Electrode assembly for a secondary battery including a current limiter

Abstract

The electrode assembly includes unit cells stacked in a stacking direction, each including an electrode structure, a separator structure, and a counter electrode structure. The electrode structure includes an electrode current collector and an electrode active material layer, the electrode structure extending in a longitudinal direction perpendicular to the stacking direction, with an end portion of the electrode current collector extending past the outer surface of the electrode active material layer and the separator structure. The electrode assembly further includes an adhesive layer including a resistive polymer material and an electrode bus bar attached to the end portion of the electrode current collector through the adhesive layer. The adhesive layer is configured to bond to the electrode bus bar and the electrode current collector below a transition temperature and to at least partially melt at or above the transition temperature to increase the electrical resistance between the electrode bus bar and the electrode current collector.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 378,493, filed October 5, 2022, which is incorporated herein by reference in its entirety.

[0002] The field of the disclosure relates generally to energy storage technologies, such as battery technologies. More particularly, the field of the disclosure relates to electrode assemblies including current limiters and secondary batteries having such electrode assemblies. [Background technology]

[0003] Secondary batteries, such as lithium-based secondary batteries, have become a desirable energy source due to their relatively high energy density, power, and shelf life. Examples of lithium secondary batteries include non-aqueous batteries such as lithium-ion batteries and lithium-polymer batteries.

[0004] Known energy storage devices, such as batteries, fuel cells, and electrochemical capacitors, typically have two-dimensional thin-layer architectures, such as flat or spirally wound (i.e., jelly-roll) thin-layer structures, where the surface area of ​​each thin layer is approximately equal to its geometric footprint (neglecting porosity and surface roughness).

[0005] FIG. 1 shows a cross-sectional view of a known thin-film type secondary battery, generally designated 10. Battery 10 includes a positive electrode current collector 15 in contact with a positive electrode 20. A negative electrode 25 is separated from positive electrode 20 by separator 30. A negative electrode 25 is in contact with a negative electrode current collector 35. As shown in FIG. 1, battery 10 is formed into a stack. The stack is sometimes covered with another separator layer (not shown) over negative electrode current collector 35, and then rolled and positioned in a can (not shown) to assemble battery 10. During the charging process, carrier ions (typically lithium) leave positive electrode 20 and travel through separator 30 into negative electrode 25. Depending on the positive electrode material used, the carrier ions either intercalate (e.g., sit in the matrix of the negative electrode material without forming an alloy) or form an alloy with the negative electrode material. During the discharge process, carrier ions leave the negative electrode 25 and travel back through the separator 30 back to the positive electrode 20 .

[0006] Three-dimensional secondary batteries can provide increased capacity and lifespan compared to thin-layer secondary batteries. Three-dimensional battery architectures (e.g., interdigitated electrode arrays) have been proposed in this literature to provide larger electrode surface areas, higher energy and power densities, improved battery capacities, and improved active material utilization compared to two-dimensional architectures (e.g., flat spiral thin layers). For example, reference to Long et al., "Three-dimensional battery architectures," Chemical Reviews, 2004, 104, 4463-4492, may be helpful in illustrating the state of the art of proposed three-dimensional battery architectures, and is therefore incorporated herein by reference as non-essential subject matter.

[0007] Energy storage devices, including secondary batteries, are at risk of releasing energy in an undesired or uncontrolled manner through accident, abuse, exposure to extreme conditions, etc. Building safety features into secondary batteries can reduce this risk and improve abuse resistance.

[0008] The safety of current lithium-based batteries can be compromised by a variety of mechanisms, many of which are related to temperature rise phenomena. Electrolyte decomposition at overcharge and high operating temperatures can result in excessive heat and thermal runaway. In the case of high-voltage cathode materials such as LiCoO2, oxygen evolution can also cause thermal runaway. In some cases, mechanical abuse can short the active materials together, thereby resulting in thermal runaway. This can be caused by overcharging the battery, an electrical short, or a short circuit associated with mechanical abuse. The rapid release of heat during chemical reactions associated with electrolyte or cathode decomposition can increase the risk of thermal runaway in conventional two-dimensional batteries.

[0009] Self-terminating devices, such as polymer or ceramic materials with a positive temperature coefficient of resistance (PTC), have been used to enhance the safety of conventional two-dimensional batteries. Such materials are sometimes referred to as resettable fuses or self-regulating thermostats. Other systems have been proposed, including non-resettable or sacrificial fuses that melt to mechanically create an open circuit that interrupts the flow of excessive current through the battery. For example, reference to P.G. Balakrishnan, R. Ramesh, and T. Prem Kumar, "Safety mechanisms in lithium-ion batteries," Journal of Power Sources, 2006, 155, 401-414, may be helpful in illustrating the state of the art in safety mechanisms for conventional lithium-ion batteries, and is therefore incorporated herein by reference as non-essential subject matter.

[0010] In at least some known lithium-based secondary batteries, resettable or non-resettable fuses have a measurable time lag between excessive current flow and fuse tripping. This time lag occurs because fuses are typically activated by heat generated when excessive current flows through the battery. Thus, excessive current flows through the battery for some time until the temperature experienced by the fuse reaches the temperature required to melt the fuse, in the case of a non-resettable fuse, or increases the resistance enough to limit the current flow through the battery, in the case of a resettable fuse using a PTC material. In some circumstances, the time lag between the initiation of excessive current and fuse tripping can result in the fuse failing to prevent thermal runaway.

[0011] Therefore, to address the problems in the known art, it would be desirable to create a three-dimensional battery that includes a current limiter for limiting the current that can flow through the battery regardless of the battery's temperature. It would further be desirable to create a three-dimensional battery in which the current limiter and attached structure operate in the event of abuse (e.g., nail penetration) to prevent thermal runaway. Summary of the Invention

[0012] In one aspect, an electrode assembly for cycling between a charged state and a discharged state is provided. The electrode assembly includes a collection of unit cells stacked on top of each other in a stacking direction, with each member of the collection of unit cells including an electrode structure, a separator structure, and a counter electrode structure. The electrode structure includes an electrode current collector and an electrode active material layer, and the electrode structure extends in a longitudinal direction perpendicular to the stacking direction, with an end portion of the electrode current collector extending in the longitudinal direction past the outer surface of the electrode active material layer and the separator structure. The counter electrode structure includes a counter electrode current collector and a counter electrode active material layer, and the counter electrode structure extends in the longitudinal direction perpendicular to the stacking direction. The electrode assembly includes an adhesive layer including a resistive polymer material and an electrode bus bar extending in the stacking direction and having a first surface and a second surface opposite the first surface, the first surface being positioned adjacent to the end portion of the electrode current collector and attached to the end portion of the electrode current collector through the adhesive layer. The adhesive layer is configured to adhere to the electrode bus bar and the electrode current collector below a transition temperature, and the adhesive layer is configured to at least partially melt at or above the transition temperature to increase the electrical resistance between the electrode bus bar and the electrode current collector.

[0013] In another aspect, an electrode assembly for cycling between a charged state and a discharged state is provided. The electrode assembly includes a collection of unit cells stacked on top of each other in a stacking direction, with each member of the collection of unit cells including an electrode structure, a separator structure, and a counter electrode structure. The electrode structure includes an electrode current collector and an electrode active material layer, and the electrode structure extends in a longitudinal direction perpendicular to the stacking direction, with an end portion of the electrode current collector extending in the longitudinal direction past the outer surface of the electrode active material layer and the separator structure. The counter electrode structure includes a counter electrode current collector and a counter electrode active material layer, and the counter electrode structure extends in a longitudinal direction perpendicular to the stacking direction. The electrode assembly includes an adhesive layer including a resistive polymer material and an electrode bus bar extending in the stacking direction and having a first surface and a second surface opposite the first surface, the first surface being positioned adjacent to the end portion of the electrode current collector and attached to the end portion of the electrode current collector through the adhesive layer. The resistive polymer material includes at least one phase change element configured to expand a volume of the adhesive layer at or above a transition temperature, the adhesive layer having a first volume below the transition temperature, and the adhesive layer configured to expand from the first volume toward a second volume at or above the transition temperature to increase the electrical resistance between the electrode bus bar and the electrode current collector.

[0014] In another aspect, an electrode assembly for cycling between a charged state and a discharged state is provided. The electrode assembly includes a collection of unit cells stacked on top of each other in a stacking direction, with each member of the collection of unit cells including an electrode structure, a separator structure, and a counter electrode structure. The electrode structure includes an electrode current collector and an electrode active material layer, and the electrode structure extends in a longitudinal direction perpendicular to the stacking direction, with an end portion of the electrode current collector extending in the longitudinal direction past the outer surface of the electrode active material layer and the separator structure. The counter electrode structure includes a counter electrode current collector and a counter electrode active material layer, and the counter electrode structure extends in a longitudinal direction perpendicular to the stacking direction. The electrode assembly includes an adhesive layer including a resistive polymer material and an electrode bus bar extending in the stacking direction and having a first surface and a second surface opposite the first surface, the first surface being positioned adjacent to the end portion of the electrode current collector and attached to the end portion of the electrode current collector through the adhesive layer. The electrode bus bar and the electrode current collector are configured to adhere to the adhesive layer below a transition temperature, and at least one of the electrode bus bar and the electrode current collector is configured to at least partially detach from the adhesive layer at or above the transition temperature.

[0015] In another aspect, an electrode assembly for cycling between a charged state and a discharged state is provided. The electrode assembly includes a collection of unit cells stacked on top of each other in a stacking direction, with each member of the collection of unit cells including an electrode structure, a separator structure, and a counter electrode structure. The electrode structure includes an electrode current collector and an electrode active material layer, and the electrode structure extends in a longitudinal direction perpendicular to the stacking direction, with an end portion of the electrode current collector extending in the longitudinal direction past the outer surface of the electrode active material layer and the separator structure. The counter electrode structure includes a counter electrode current collector and a counter electrode active material layer, and the counter electrode structure extends in a longitudinal direction perpendicular to the stacking direction. The electrode assembly includes an adhesive layer including a resistive polymer material and an electrode bus bar extending in the stacking direction and having a first surface and a second surface opposite the first surface, the first surface being positioned adjacent to the end portion of the electrode current collector and attached to the end portion of the electrode current collector through the adhesive layer. The first surface of the electrode bus bar and the outer surface of the electrode active material layer are separated by a separation distance, and the separation distance between the first surface of the electrode bus bar and the outer surface of the electrode active material layer changes in response to at least one of an electrical short and a current passing through the adhesive layer.

[0016] Various refinements exist to the features described in connection with the above aspects. Additional features may also be incorporated into the above aspects. These refinements and additional features may exist individually or in any combination. For example, the various features discussed below in connection with any of the illustrated embodiments may be incorporated into any of the above aspects, alone or in any combination. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view of an existing thin-film battery. [Figure 2] FIG. 1 is a simplified diagram of an example electrode assembly for cycling between charged and discharged states in a secondary battery. [Figure 3A] 3 is a simplified diagram of the end of the counter electrode current collector of the electrode assembly of FIG. 2. [Figure 3B]FIG. 3B is a view of the end of the counter electrode current collector of FIG. 3A connected to a counter electrode bus bar. [Figure 4A] 3 is a top view of a pair of electrode structures of the electrode assembly of FIG. 2 with current collectors attached to bus bars through current limiters. [Figure 4B] 4B is a side view of one of the electrode structures of FIG. 4A with a current collector attached to a bus bar through a current limiter. FIG. [Figure 5] FIG. 1 is a simplified diagram of another example electrode assembly for cycling between charged and discharged states in a secondary battery. [Figure 6] FIG. 10 is a simplified diagram of yet another example electrode assembly for cycling between charged and discharged states in a secondary battery. [Figure 7] FIG. 10 is a simplified diagram of yet another example electrode assembly for cycling between charged and discharged states in a secondary battery. [Figure 8A] FIG. 1 is a simplified isometric view of an anode electrode structure for use in an electrode assembly. [Figure 8B] FIG. 1 is a simplified isometric view of a cathode electrode structure for use in an electrode assembly. [Figure 9] FIG. 1 is an isometric view of an example of a stacked cell created as part of the manufacture of a secondary battery. [Figure 10] FIG. 10 is a partial top view of the stacked cell shown in FIG. 9. [Figure 11A] FIG. 10 is an isometric view of the stacked cells shown in FIG. 9 positioned in a packaging station. [Figure 11B] FIG. 11B is an isometric view of the stacked cells shown in FIG. 11A with a battery package positioned thereon. [Figure 12] FIG. 1 is a simplified diagram of a unit cell of an electrode assembly being tested in a forced internal short circuit test. [Figure 13] FIG. 1 is a simplified diagram of a portion of another example electrode assembly for cycling between charged and discharged states in a secondary battery. [Figure 14]FIG. 1 is a side view of an electrode structure with a current limiter and its current collector attached to a busbar through an interface layer applied to the busbar. [Figure 15] FIG. 1 is a side view of an electrode structure with a current limiter and electrode current collector attached to a bus bar through an interface layer applied to the current collector. [Figure 16] FIG. 1 is a side view of an electrode structure with a current limiter, an interface layer applied to the current electrode current collector, and the current collector attached to the bus bar through an interface layer applied to the bus bar. [Figure 17] FIG. 10 is a side view of a counter electrode current collector connected to a counter electrode bus bar without the use of a slot in the current collector. [Figure 18] FIG. 10 is a side view of one of the electrode structures with the current collector attached to the bus bar through a current limiter formed as a single layer without slots in the current collector. [Figure 19] FIG. 10 is a side view of one of the electrode structures with the current collector attached to the busbar through a separate current limiter formed as a single layer without the use of slots in the current collector. [Figure 20] FIG. 10 is an isometric view of another example stacked cell created as part of the manufacture of a secondary battery. [Figure 21] FIG. 10 is a side view of another electrode structure with a current collector attached to a bus bar through a current limiter formed as a single layer without the use of slots in the current collector. [Figure 22] FIG. 10 is a side view of an alternative electrode structure in which the current collector is attached to the busbar through a separate current limiter formed as a single layer without the use of slots in the current collector. DETAILED DESCRIPTION OF THE INVENTION

[0018] Corresponding reference characters indicate corresponding parts throughout the drawings.

[0019] definition As used herein, "a," "an," and "the" (i.e., singular) refer to plural referents unless the context clearly dictates otherwise. For example, in one instance, reference to an "electrode" includes both a single electrode and a plurality of similar electrodes.

[0020] As used herein, "about" and "approximately" refer to plus or minus 10%, 5%, or 1% of the stated value. For example, in one example, about 250 μm includes 225 μm to 275 μm. As a further example, in one example, about 1,000 μm includes 900 μm to 1,100 μm. Unless otherwise indicated, all numbers expressing quantities (e.g., measurements, etc.) and the like used in the specification and claims should be understood as being modified in all instances by the term "about." Accordingly, unless otherwise indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations. Each numerical parameter should be construed, at least in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0021] "Anode" as used herein in the context of a secondary battery refers to the negative electrode in the secondary battery.

[0022] As used herein, "anode material" or "anode active" means a material suitable for use as the negative electrode of a secondary battery.

[0023] "Cathode" as used herein in the context of a secondary battery refers to the positive electrode in the secondary battery.

[0024] As used herein, "cathode material" or "cathode active" means a material suitable for use as the positive electrode of a secondary battery.

[0025] "Conversion chemical active material" or "conversion chemical material" refers to a material that undergoes a chemical reaction during the charge and discharge cycle of a secondary battery.

[0026] As used herein, "counter electrode" may refer to either the negative electrode or the opposite positive electrode (anode or cathode) of a secondary battery, unless the context clearly indicates otherwise.

[0027] As used herein, "counter electrode current collector" may refer to the negative electrode current connector or the opposite positive electrode current collector (anode or cathode) of a secondary battery, unless the context clearly indicates otherwise.

[0028] As used herein, "cycling" in the context of cycling a secondary battery between a charging state and a discharging state refers to charging and / or discharging the battery to move it in a cycle from a first state, either a charging state or a discharging state, to a second state that is the opposite of the first state (i.e., a charging state if the first state was discharged, or a discharging state if the first state was charged), and then returning the battery to the first state to complete the cycle. For example, a single cycle of a secondary battery between a charging state and a discharging state may include charging the battery from the discharging state to the charging state, and then discharging it to the discharging state to complete the cycle, as in a charging cycle. A single cycle may also include discharging the battery from the charging state to the discharging state, and then charging it to the charging state to complete the cycle, as in a discharging cycle.

[0029] As used herein, "electrochemically active material" means an anode active material or a cathode active material.

[0030] As used herein, "electrode" may refer to either the negative or positive electrode (anode or cathode) of a secondary battery, unless the context clearly indicates otherwise.

[0031] As used herein, "electrode current collector" may refer to either the negative or positive (anode or cathode) current collector of a secondary battery, unless the context clearly indicates otherwise.

[0032] As used herein, "electrode material" may refer to either an anode material or a cathode material, unless the context clearly indicates otherwise.

[0033] As used herein, "electrode structure" may refer to an anode structure (e.g., anode structure) or a cathode structure (e.g., cathode structure) adapted for use in a battery, unless the context clearly indicates otherwise.

[0034] As used herein, "longitudinal axis," "lateral axis," and "vertical axis" refer to mutually perpendicular axes (i.e., each perpendicular to one another) that define a length L, a width W, and a height H, respectively. For example, as used herein, "longitudinal axis," "lateral axis," and "vertical axis" are analogous to a Cartesian coordinate system used to define three-dimensional aspects or orientations. As such, the description of elements of the presently disclosed subject matter is not limited to the particular axis(es) used to describe the three-dimensional orientation of the elements. Alternatively stated, axes may be interchangeable when referring to three-dimensional aspects of the disclosed subject matter.

[0035] Embodiments of the present disclosure relate to batteries, such as three-dimensional secondary batteries, and electrode assemblies for such batteries that include a current limiter to limit the current that can flow through the battery, thereby limiting heat gain, helping to prevent thermal runaway, and improving battery safety.

[0036] 2 is a simplified diagram of an example electrode assembly 200 for cycling between charge and discharge states in a battery. The electrode assembly 200 includes a collection of electrode structures 202, a collection of counter electrode structures 204, a collection of separator structures 205, a collection of current limiters 206, an electrode bus bar 208, and a counter electrode bus bar 210. The example embodiment is an electrode assembly suitable for use in a three-dimensional secondary battery, in which the electrode structures 202 and counter electrode structures 204 each extend primarily along a length (or longitudinal) direction L and a height direction H of the assembly, and are separated from each other along a width direction W. In other embodiments, the electrode assembly 200 may be for use in a thin-film secondary battery.

[0037] A voltage difference V exists between adjacent electrode structures 202 and counter electrode structures 204, and the adjacent pair can be considered a unit cell. Each unit cell has a capacitance C determined by the assembly and configuration of the electrode structures 202 and counter electrode structures 204. In the example embodiment, each unit cell generates a voltage difference of about 4.35 volts. In other embodiments, each unit cell has a voltage difference of about 0.5 volts, about 1.0 volts, about 1.5 volts, about 2.0 volts, about 2.5 volts, about 3.0 volts, about 3.5 volts, about 4.0 volts, 4.5 volts, about 5.0 volts, 4-5 volts, or any other suitable voltage. During cycling between charge and discharge, the voltage can fluctuate, for example, between about 2.5 volts and about 4.35 volts. The capacity C of the unit cell in the example embodiment is about 25 mAh. In other embodiments, the capacity C of the unit cell is about 50 mAh, less than 50 mAh, or any other suitable capacity. In some embodiments, the capacity C of the unit cell can be up to about 500 mAh.

[0038] In the example embodiment, the electrode structures 202 and counter electrode structures 204 are generally rectangular and arranged in an interdigitated configuration, i.e., the electrode structures 202 and counter electrode structures 204 extend from opposing electrode bus bars 208 and counter bus bars 210 and alternate along the length direction L. In other embodiments, other shapes and arrangements of the electrode structures 202 and counter electrode structures 204 are used. For example, the electrode assembly 200 (and the battery it is included in) can have any of the shapes and / or arrangements described or shown in U.S. Pat. No. 9,166,230, the entire contents of which are incorporated herein by reference.

[0039] Each member of the collection of electrode structures 202 includes an electrode active material 212 and an electrode current collector 214. The electrode structures 202 are electrically connected in parallel to an electrode bus bar 208 through a current limiter 206. The electrode structures 202 can be anodes or cathodes, although in example embodiments, all of the electrode structures 202 in the collection are of the same type (anode or cathode). In some other embodiments, the electrode structures 202 may include anode and cathode structures. Each member of the collection of counter electrode structures 204 includes a counter electrode active material 216 and a counter electrode current collector 218. The counter electrode structures 204 are electrically connected in parallel to a counter electrode bus bar 210. In example embodiments, the counter electrode structures 204 are all of the same type (anode or cathode), the opposite type from the electrode structures 202. In some other embodiments, the counter electrode structures 204 may include anode and cathode structures. Although only two electrode structures 202 and two counter electrode structures 204 are shown in FIG. 2 , the electrode assembly 200 can have any number of electrode structures 202 and counter electrode structures 204. The assemblies of electrode structures 202 and counter electrode structures 204 generally include the same number of elements, but in some embodiments, they can include different numbers of electrode structures 202 and counter electrode structures 204. For example, some embodiments can start and end with the same electrode structure 202 or counter electrode structure 204, resulting in another electrode structure 202 or counter electrode structure 204. In some embodiments, the assemblies of electrode structures 202 and counter electrode structures 204 include at least 20 elements each. Some embodiments include assemblies of electrode structures 202 and counter electrode structures 204 with approximately 10 elements each, 10-25 elements each, 25-250 elements each, 25-150 elements each, 50-150 elements each, or up to 500 elements each. In some embodiments, the electrode structure 202 or the counter electrode structure 204 does not contain an active material when discharged, and only the other of the counter electrode structure 204 or the electrode structure 202 contains an active material when discharged.

[0040] The cathode type of electrode structure 202 or counter electrode structure 204 includes a current collector 214 or 218 that is a cathode current collector. The cathode current collector may include aluminum, nickel, cobalt, titanium, and tungsten, or alloys thereof, or any other material suitable for use as a cathode current collector layer. Generally, the cathode current collector has a thickness of at least about 10 3 For example, in one such embodiment, the cathode current collector has an electrical conductivity of at least about 10 Siemens / cm. 4 By way of further example, in one such embodiment, the cathode current collector has a conductivity of at least about 10 Siemens / cm. 5 The anode type of electrode structure 202 or counter electrode structure 204 includes anode current collector 214 or 218. The anode current collector may include conductive materials such as copper, carbon, nickel, stainless steel, cobalt, titanium, and tungsten, and alloys thereof, or any other material suitable as an anode current collector layer.

[0041] The cathode type of electrode structure 202 or counter electrode structure 204 includes an active material 212 or 216 that is a cathode active material. The cathode active material can be an intercalation-type chemically active material, a conversion-type chemically active material, or a combination thereof.

[0042] Exemplary conversion chemical materials useful in the present disclosure include S (or its lithiated form, LiS), LiF, Fe, Cu, Ni, FeF, FeO d F 3.2d , FeF3, CoF3, CoF2, CuF2, NiF2, where 0≦d≦0.5 and the like.

[0043] Exemplary cathode active materials include any of a wide range of cathode active materials. For example, in the case of a lithium-ion battery, the cathode active material may include a cathode material selected from transition metal oxides, transition metal sulfides, transition metal nitrides, lithium transition metal oxides, and lithium transition metal sulfides, and lithium transition metal nitrides may be used selectively. The transition metal elements of these transition metal oxides, transition metal sulfides, and transition metal nitrides may include metal elements having a d-shell or f-shell. Specific examples of such metal elements include Sc, Y, lanthanides, actinides, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pb, Pt, Cu, Ag, and Au. Additional cathode active materials include LiCoO, LiNiO.5MnO, Li(NixCoyAlz)O, LiFePO, LiMnO, VO, oxymolybdenum sulfide, phosphate, silicate, vanadate, sulfur, sulfur compounds, oxygen (air), Li(NixMnyCoz)O, and combinations thereof. Furthermore, the compound for the cathode active material layer can include lithium-containing compounds further comprising a metal oxide or metal phosphate, such as a compound containing lithium, cobalt, and oxygen (e.g., LiCoO), a compound containing lithium, manganese, and oxygen (e.g., LiMnO), and a compound containing lithium iron and phosphate (e.g., LiFePO). In one embodiment, the cathode active material includes at least one of lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron phosphate, or a composite oxide formed from a combination of the foregoing oxides.In another embodiment, the cathode active material may include lithium cobalt oxide (LiCoO₂), lithium nickel oxide (LiNiO₂), etc., or a compound substituted with one or more transition metals; lithium manganese oxides such as Li₁₊ₓMn₂₋ₓO₄ (where x is from 0 to 0.33), LiMnO₃, LiMn₂O₃, LiMnO₂; lithium copper oxide (Li₂CuO₂); vanadium oxides such as LiV₃O₈, LiFe₃O₄, V₂O₅, Cu₂V₂O₇, Ni-site type lithium nickel oxides represented by the chemical formula LiNi₁₋ₓMₓO₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3); lithium manganese composite oxides represented by the chemical formula LiMn₂₋ₓMₓO₂ (where M = Co, Ni, Fe, Cr, Zn, or Ta, and x = 0.01 to 0.1) or Li₂Mn₃MO₈ (where M = Fe, Co, Ni, Cu, or Zn); LiMn₂O₄ in which a part of Li is substituted with an alkaline earth metal ion; disulfide compounds; and one or more of Fe₂(MoO₄)₃, etc. In one embodiment, the cathode active material may include a lithium metal phosphate having an olivine crystal structure of the formula.

[0044] Li₁₊ₐFe₁₋ₓM′ₓ(PO₄₋b)Xb, where M’ is at least one selected from Al, Mg, Ni, Co, Mn, Ti, Ga, Cu, V, Nb, Zr, Ce, In, Zn, and Y, X is at least one selected from F, S, and N, -0.5 ≤ a ≤ +0.5, 0 ≤ x ≤ 0.5, and 0 ≤ b ≤ 0.1, and at least one of LiFePO₄, Li(Fe, Mn)PO₄, Li(Fe, Co)PO₄, Li(Fe, Ni)PO₄, etc. In one embodiment, the cathode active material includes at least one of LiCoO₂, LiNiO₂, LiMnO₂, LiMn₂O₄, LiNi₁₋yCoₙO₂, LiCo₁₋yMnₙO₂, LiNi₁₋yMnₙO₂ (0 ≤ y ≤ 1), Li(NiaCobMnc)O₄ (0 < a < 2, 0 < b < 2, 0 < c < 2, and a + b + c = 2), LiMn₂₋zNiₙO₄, LiMn₂₋zCoₙO₄ (0 < z < 2), LiCoPO₄, and LiFePO₄, or a mixture of two or more thereof.

[0045] In yet another embodiment, the negative electrode active material may include elemental sulfur (S), a sulfur-based compound, or a mixture thereof. The sulfur-based compound may specifically include Li2Sn (n≧1), an organic sulfur compound, a carbon-sulfur polymer ((CSx)n: x=2.5-50, n≧2), or the like. In yet another embodiment, the negative electrode active material may include oxides of lithium and zirconium.

[0046] In yet another embodiment, the cathode active material can include at least one composite oxide of lithium and a metal such as cobalt, manganese, nickel, or a combination thereof, and can be used. Examples thereof include LiaA1-bMbD2 (where 0.90 ≦ a ≦ 1 and 0 ≦ b ≦ 0.5); LiaE1-bMbO2-cDc (where 0.90 ≦ a ≦ 1, 0 ≦ b ≦ 0.5, and 0 ≦ c ≦ 0.05); LiE2-bMbO4-cDc (where 0 ≦ b ≦ 0.5 and 0 ≦ c ≦ 0.05); LiaNi1-b-cCobMcDa (where 0.90 ≦ a ≦ 1, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, and 0 < a ≦ 2); LiaNi1-b-cCobMcO2-aXa (where 0.9 ≦ a ≦ 1, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, and 0 < a < 2); LiaNi1-b-cCobMcO2-aX2 (where 0.90 ≦ a ≦ 1, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, and 0 < a < 2); LiaNi1-b-cMnbMcDa (where 0.90 ≦ a ≦ 1, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, and 0 < a ≦ 2); LiaNi1-b-cMnbMcO2-aXa (where 0.90 ≦ a ≦ 1, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, and 0 < a < 2); LiaNi1-b-cMnbMcO2-aX2 (where 0.90 ≦ a ≦ 1, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, and 0 < a < 2); LiaNibEcGdO2 (where 0.90 ≦ a ≦ 1, 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.5, and 0.001 ≦ d ≦ 0.1); LiaNibCocMndGeO2 (where 0.90 ≦ a ≦ 1, 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.5, 0 ≦ d ≦ 0.5, and 0.001 ≦ e ≦ 0.1); LiaNiGbO2 (where 0.90 ≦ a ≦ 1 and 0.001 ≦ b ≦ 0.1); LiaCoGbO2 (where 0.90 ≦ a ≦ and 0.001 ≦ b ≦ 0.1); LiaMnGbO2 (where 0.90 ≦ a ≦ 1 and 0.001 ≦ b ≦ 0.1); LiaMn2GbO4 (where 0.90 ≦ a ≦ 1 and 0.001 ≦ b ≦ 0.1); QO2; QS2; LiQS2; V2O5; LiV2O5; LiX′O2; LiNiVO4; Li(3-f)J2(PO4)3 (0 ≦ f ≦ 2); Li(3-f)Fe2(PO4)3 (0 ≦ f ≦ 2); and LiFePO4.In the above formula, A is Ni, Co, Mn, or a combination thereof; M is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; X is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; X' is Cr, V, Fe, Sc, Y, or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof. For example, LiCoO2, LiMnxO2x (x = 1 or 2), LiNi1-xMnxO2x (0 < x < 1), LiNi1-x-yCoxMnyO2 (0 ≦ x ≦ 0.5, 0 ≦ y ≦ 0.5), or FePO4 can be used. In one embodiment, the cathode active material includes at least one of lithium compounds such as lithium cobalt oxide, lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide, lithium nickel cobalt manganese oxide, lithium manganese oxide, or lithium iron phosphate; nickel sulfide; copper sulfide; sulfur; iron oxide; or vanadium oxide.

[0047] In one embodiment, the cathode active material can include a sodium-containing material, such as at least one of oxides of the formula NaM1aO2, such as NaFeO2, NaMnO2, NaNiO2, or NaCoO2, or oxides represented by the formula NaMn1-aM1aO2 (where M1 is at least one transition metal element, and 0≦a<1). Exemplary cathode active materials include Na[Ni1 / 2Mn1 / 2]O2, Na2 / 3[Fe1 / 2Mn1 / 2]O2, and oxides represented by the formula Na0.44Mn1-aM1aO2, Na0.7Mn1-aM1aO2.05. an oxide represented by the formula: an (wherein M1 is at least one transition metal element and 0≦a<1); an oxide represented by the formula: NabM2cSi12O30, such as Na6Fe2Si12O30 or Na2Fe5Si12O (wherein M2 is at least one transition metal element and 2≦b≦6 and 2≦c≦5); an oxide represented by the formula: NadM3eSi6O18, such as Na2Fe2Si6O18 or Na2MnFeSi6O18 (wherein M3 is at least one transition metal element and 3≦d≦6 and 1≦e≦2); an oxide represented by the formula: NafM4gSi2O6, such as Na2FeSiO6 (wherein M4 is a transition metal element, magnesium oxides, where f is at least one element selected from magnesium (Mg) and aluminum (Al), and the formula is 1≦f≦2 and 1≦g≦2; phosphates, such as NaFePO, NaFe(PO), NaV(PO, and NaCo(PO)P; borates, such as NaFeBO or NaFe(BO); fluorides, such as NahMf (where M is at least one transition metal element, and 2≦h≦3), such as NaFeF or NaMnF; and fluorophosphates, such as NaV(PO)F and NaV(PO)FO. The positive electrode active material is not limited to those described above, and any suitable positive electrode active material used in the art can be used.In one embodiment, the positive electrode active material preferably comprises a layered-type oxide cathode material such as NaMnO2, Na[NiMn]O2, and Na2 / 3[FeMns]O2, a phosphate cathode such as Na3V2(PO4)3 and Na4Co3(PO4)2P2O7, or a fluorophosphate cathode such as Na3V2(PO4)2F3 and Na3V2(PO4)2FO2.

[0048] In yet another embodiment, the cathode active material may further include one or more conductive aids and / or binders, which may be, for example, any of the conductive aids and / or binders described for the anode active material herein.

[0049] Generally, the cathode active material has a thickness of at least about 20 μm when either the electrode structure 202 or the counter electrode structure 204 is a cathode-type structure. For example, in one embodiment, the cathode active material has a thickness of at least about 40 μm. By way of further example, in such an embodiment, the cathode active material has a thickness of at least about 60 μm. By way of further example, in such an embodiment, the cathode active material has a thickness of at least about 100 μm. However, typically, the cathode active material has a thickness of less than about 90 μm, or even less than about 70 μm.

[0050] The anode type of electrode structure 202 or counter electrode structure 204 includes an active material 212 or 216 that is an anode active material. Generally, anode active materials include: (a) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), nickel (Ni), cobalt (Co), and cadmium (Cd); (b) alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Ni, Co, or Cd with other elements; (c) Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, (d) oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Fe, Ni, Co, V, or Cd, and mixtures, composites, or lithium-containing composites thereof; (d) salts and hydroxides of Sn; (e) lithium titanate, lithium manganate, lithium aluminate, lithium-containing titanium oxide, lithium transition metal oxide, ZnCo2O4; (f) particles of graphite and carbon; (g) lithium metal; and (h) combinations thereof.

[0051] Exemplary anode active electroactive materials include carbon materials such as graphite and soft or hard carbon, or any of a range of metals, metalloids, alloys, oxides, and compounds capable of forming alloys with lithium. Specific examples of metals or metalloids that can comprise the anode material include graphite, tin, lead, magnesium, aluminum, boron, gallium, silicon, Si / C composites, Si / graphite blends, SiOx, porous Si, intermetallic Si alloys, indium, zirconium, germanium, bismuth, cadmium, antimony, silver, zinc, arsenic, hafnium, yttrium, lithium, sodium, graphite, carbon, lithium titanate, palladium, and mixtures thereof. In one exemplary embodiment, the anode active material comprises aluminum, tin, or silicon, or an oxide thereof, a nitride thereof, a fluoride thereof, or another alloy thereof. In another exemplary embodiment, the anode active material comprises silicon, silicon oxide, or an alloy thereof.

[0052] In a further embodiment, the anode active material may include lithium metal, lithium alloy, carbon, petroleum coke, activated carbon, graphite, silicon compounds, tin compounds, and alloys thereof. In one embodiment, the anode active material includes carbon such as non-graphitized carbon and graphite-based carbon; LixFe2O3 (0 ≦ x ≦ 1), LixWO2 (0 ≦ x ≦ 1), SnxMe1-xMe′yOz (Me: Mn, Fe, Pb, Ge; Me′: Al, B, P, Si, elements found in Group 1, Group 2, and Group 3 of the periodic table, halogen; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8), lithium metal; lithium alloy; silicon-based alloy, tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5; conductive polymers such as polyacetylene, Li-Co-Ni-based materials, and the like. In one embodiment, the anode active material may include a carbon-based active material including crystalline graphite such as natural graphite and synthetic graphite, and amorphous carbon such as soft carbon and hard carbon. Other examples of carbon materials suitable for the anode active material may include graphite, Kish graphite, pyrolytic carbon, mesophase pitch-based carbon fibers, mesocarbon microbeads, mesophase pitch, graphitized carbon fibers, and high-temperature sintered carbon such as coke derived from petroleum or coal tar pitch. In one embodiment, the negative electrode active material may include tin oxide, titanium nitrate, and silicon. In another embodiment, the negative electrode may include a lithium metal such as a lithium metal film, or a lithium alloy such as an alloy of lithium and one or more types of metals selected from the group consisting of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al, and Sn.In yet another embodiment, the anode active material may include metal compounds such as Si, Al, C, Pt, Sn, Pb, Ir, Ni, Cu, Ti, Na, K, Rb, Cs, Fr, Be, Ca, Sr, Sb, Ba, Ra, Ge, Zn, Bi, In, Mg, Ga, Cd, Si alloys, Sn alloys, and Al alloys that can alloy and / or intercalate with lithium; metal oxides such as SiOv (0 < v < 2), SnO2, vanadium oxide, or lithium vanadium oxide that can dope and undope lithium ions; and composites including metal compounds and carbon materials such as Si-C composites or Sn-C composites. For example, in one embodiment, materials that can alloy / intercalate with lithium are metals such as lithium, indium, tin, aluminum, or silicon, or their alloys; transition metal oxides such as Li4 / 3Ti5 / 3O4 or SnO; and carbonaceous materials such as artificial graphite, graphite carbon fiber, resin calcined carbon, pyrolytic vapor-grown carbon, cork, mesocarbon microbeads ("MCMB"), furfuryl alcohol resin calcined carbon, polyacene, pitch-based carbon fiber, vapor-grown carbon fiber, or natural graphite. In yet another embodiment, the negative electrode active material may include a composition suitable for carrier ions such as sodium or magnesium. For example, in one embodiment, the negative electrode active material may include a layered carbonaceous material and a composition of the formula NaxSny-zMz (where M is Ti, K, Ge, P, or a combination thereof, 0 < x ≦ 15, 1 ≦ y ≦ 5, and 0 ≦ z ≦ 1) disposed between the layers of the layered carbonaceous material.

[0053] In one embodiment, the negative electrode active material may further include a conductive material and / or conductive additive such as carbon-based materials, carbon black, graphite, graphene, activated carbon, carbon fiber, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, etc.; conductive fibers such as carbon fibers and metal fibers; conductive tubes such as carbon nanotubes; metal powders such as fluorocarbon powder, aluminum powder, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide, or polyphenylene derivatives. In addition, metal fibers such as metal mesh; metal powders such as copper, silver, nickel, and aluminum; or organic conductive materials such as polyphenylene derivatives may also be used. In yet another embodiment, a binder such as one or more of polyethylene, polyethylene oxide, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene-butadiene rubber, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, vinylidene fluoride-pentafluoropropylene copolymer, propylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene copolymer, ethylene-acrylic acid copolymer, and the like may be provided and may be used either alone or as a mixture.

[0054] In one embodiment, the positive electrode active material is microstructured to provide a significant void volume fraction to accommodate volume expansion and contraction as lithium ions (or other carrier ions) are incorporated into or released from the negative electrode active material during charge and discharge processes. Generally, the void volume fraction of the (each of) the positive electrode active material layer(s) is at least 0.1. Typically, however, the void volume fraction of the (each of) the positive electrode active material layer(s) is 0.8 or less. For example, in one embodiment, the void volume fraction of the (each of) the positive electrode active material layer(s) is about 0.15 to about 0.75. By way of further example, in one embodiment, the void volume fraction of the (each of) the positive electrode active material layer(s) is about 0.2 to about 0.7. By way of further example, in one embodiment, the void volume fraction of the (each of) the positive electrode active material layer(s) is about 0.25 to about 0.6.

[0055] Depending on the composition of the microstructured anode active material and its method of formation, the microstructured anode active material can comprise a macroporous, microporous, or mesoporous material layer, or a combination thereof, such as a combination of mesoporous and macroporous. Microporous materials are typically characterized by pore dimensions of less than 10 nm, wall dimensions of less than 10 nm, pore depths of 1 to 50 micrometers, and pore morphologies generally characterized by a "spongy" and irregular appearance, non-smooth walls, and branched pores. Mesoporous materials are typically characterized by pore dimensions of 10 to 50 nm, wall dimensions of 10 to 50 nm, pore depths of 1 to 100 micrometers, and pore morphologies generally characterized by somewhat well-defined branched or dendritic pores. Macroporous materials are typically characterized by pore dimensions greater than 50 nm, wall dimensions greater than 50 nm, pore depths between 1 and 500 micrometers, and various pore morphologies that can be linear, branched, or dendritic, and smooth or rough-walled. Additionally, the pore volume can include open porosity or closed porosity, or a combination thereof. In one embodiment, the pore volume includes open porosity, i.e., the positive electrode active material includes pores with openings in the lateral surfaces of the negative electrode active material through which lithium ions (or other carrier ions) can pass in and out of the positive electrode active material; for example, lithium ions can enter the positive electrode active material through the pore openings after exiting the negative electrode active material. In another embodiment, the pore volume includes closed porosity, i.e., the positive electrode active material includes pores that are surrounded by the positive electrode active material. Generally, open porosity can provide a larger interfacial surface area for carrier ions, while closed porosity tends to be less susceptible to solid electrolyte interfaces, each providing room for expansion of the anode active material upon entry of carrier ions. Thus, in certain embodiments, it is preferred that the anode active material include a combination of open and closed porosity.

[0056] In one embodiment, the anode active material comprises porous aluminum, tin, or silicon, or an alloy, oxide, or nitride thereof. The porous silicon layer can be formed, for example, by anodization, by etching (e.g., by depositing a noble metal such as gold, platinum, silver, or gold / palladium on the surface of single-crystal silicon and etching the surface with a mixture of hydrofluoric acid and hydrogen peroxide), or by other methods known in the art, such as patterned chemical etching. Additionally, the porous anode active material generally has a porosity of at least about 0.1 but less than 0.8 and a thickness of about 1 to about 100 micrometers. For example, in one embodiment, the anode active material comprises porous silicon, has a thickness of about 5 to about 100 micrometers, and has a porosity of about 0.15 to about 0.75. By way of further example, in one embodiment, the anode active material comprises porous silicon, has a thickness of about 10 to about 80 micrometers, and has a porosity of about 0.15 to about 0.7. By way of further example, in one such embodiment, the anode active material comprises porous silicon, has a thickness of about 20 to about 50 micrometers, and has a porosity of about 0.25 to about 0.6. By way of further example, in one embodiment, the anode active material comprises a porous silicon alloy (such as nickel silicide), has a thickness of about 5 to about 100 micrometers, and has a porosity of about 0.15 to about 0.75.

[0057] In another embodiment, the anode active material comprises fibers of aluminum, tin, or silicon, or alloys thereof. Individual fibers can have a diameter (thickness dimension) of about 5 nm to about 10,000 nm and a length generally corresponding to the thickness of the anode active material. Silicon fibers (nanowires) can be formed by chemical vapor deposition or other techniques known in the art, such as vapor-liquid-solid (VLS) growth and solid-liquid-solid (SLS) growth. Additionally, the anode active material generally has a porosity of at least about 0.1 but less than 0.8 and a thickness of about 1 to about 200 micrometers. For example, in one embodiment, the anode active material comprises silicon nanowires, has a thickness of about 5 to about 100 micrometers, and has a porosity of about 0.15 to about 0.75. By way of further example, in one embodiment, the anode active material comprises silicon nanowires, has a thickness of about 10 to about 80 micrometers, and has a porosity of about 0.15 to about 0.7. By way of further example, in one such embodiment, the anode active material comprises silicon nanowires, has a thickness of about 20 to about 50 micrometers, and has a porosity of about 0.25 to about 0.6. By way of further example, in one embodiment, the anode active material comprises silicon alloy (such as nickel silicide) nanowires, has a thickness of about 5 to about 100 micrometers, and has a porosity of about 0.15 to about 0.75.

[0058] In yet another embodiment, the positive electrode (i.e., the electrode or counter electrode) is coated with a particulate lithium material selected from the group consisting of stabilized lithium metal particles, such as lithium carbonate stabilized lithium metal powder, lithium silicate stabilized lithium metal powder, or other sources of stabilized lithium metal powder or ink. The particulate lithium material is coated in an amount of about 0.05 to 5 mg / cm. 2 , for example, about 0.1 to 4 mg / cm 2 , or even about 0.5-3 mg / cm 2 The lithium particulate material may be applied onto the negative electrode active material layer by spraying, packing, or otherwise disposing the lithium particulate material onto the negative electrode active material layer at a loading of 0.05 to 0.15 μm. 50The average particle size (D) can be 5 to 200 μm, for example, about 10 to 100 μm, 20 to 80 μm, or even about 30 to 50 μm. 50 ) can be defined as the particle size corresponding to 50% on the cumulative volume-based particle size distribution curve. 50 ) can be measured, for example, using laser diffraction methods.

[0059] The anode type of electrode structure 202 or counter electrode structure 204 includes a current collector 214 or 218 that is an anode current collector. Generally, the anode current collector has a capacitance of at least about 10 3 For example, in one such embodiment, the anode current collector has an electrical conductivity of at least about 10 Siemens / cm. 4 By way of further example, in one such embodiment, the anode current collector has a conductivity of at least about 10 Siemens / cm. 5 It has a conductivity of Siemens / cm. Exemplary electrically conductive materials suitable for use as the anode current collector include metals such as copper, nickel, cobalt, titanium, and tungsten, and alloys thereof.

[0060] In one embodiment, when either the electrode current collector 214 or the counter electrode current collector 218 is of the anode type, the anode current collector has an electrical conductivity substantially greater than the electrical conductivity of its associated electrode active material 212 or counter electrode active material 216. For example, in one embodiment, when there is an applied current to store energy in the device or an applied load to discharge the device, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material is at least 100:1. By way of further example, in some embodiments, when there is an applied current to store energy in the device or an applied load to discharge the device, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material is at least 500:1. By way of further example, in some embodiments, when there is an applied current to store energy in the device or an applied load to discharge the device, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material is at least 1000:1. By way of further example, in some embodiments, when there is an applied current to store energy in the device or an applied load to discharge the device, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material layer is at least 5000: 1. By way of further example, in some embodiments, when there is an applied current to store energy in the device or an applied load to discharge the device, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material layer is at least 10,000: 1.

[0061] Generally, the cathode-type current collector, whether electrode current collector 214 or counter electrode current collector 218, is cathode-type, can include metals such as aluminum, carbon, chromium, gold, nickel, NiP, palladium, platinum, rhodium, ruthenium, alloys of silicon and nickel, titanium, or combinations thereof (see, "Current collectors for positive electrodes of lithium-based batteries" by A. H. Whitehead and M. Schreiber, Journal of the Electrochemical Society, 152(11) A2105-A2113 (2005)). By way of further example, in one embodiment, the cathode current collector includes gold or an alloy thereof, such as gold silicide. By way of further example, in one embodiment, the cathode current collector includes nickel or an alloy thereof, such as nickel silicide.

[0062] Referring to FIG. 8A, each anode electrode structure, i.e., each electrode structure 202 or counter electrode structure 204 of the anode type, is aligned along the longitudinal axis (A E ) measured along the length (L E ) and width (W E ) and length L E and width W E The height (H E ) and.

[0063] Length L of the anode electrode assembly E will vary depending on the energy storage device and its intended use. In general, however, the anode electrode structure typically has a length L in the range of about 5 mm to about 500 mm. E For example, in one such embodiment, the anode electrode structure has a length L of about 10 mm to about 250 mm. E By way of further example, in one such embodiment, the anode assembly members have a length L of about 25 mm to about 100 mm. EAccording to one embodiment, the anode electrode structure includes one or more first electrode members having a first length and one or more second electrode members having a second length other than the first length. In yet another embodiment, the different lengths of the one or more first electrode members and the one or more second electrode members can be selected to conform to a predetermined shape of the electrode assembly, such as an electrode assembly shape having different lengths along one or more of the longitudinal and / or lateral axes, and / or to provide predetermined performance characteristics of the secondary battery.

[0064] Anode electrode structure width W E will vary depending on the energy storage device and its intended use. In general, however, each anode electrode structure typically has a width W in the range of about 0.01 mm to 2.5 mm. E For example, in one embodiment, each anode electrode structure has a width W E By way of further example, in one embodiment, the width W of each anode electrode structure is in the range of about 0.025 mm to about 2 mm. E is in the range of about 0.05 mm to about 1 mm. According to one embodiment, the anode electrode structure includes one or more first electrode members having a first width and one or more second electrode members having a second width other than the first width. In yet another embodiment, the different widths of the one or more first electrode members and the one or more second electrode members can be selected to conform to a predetermined shape of the electrode assembly, such as an electrode assembly shape having different widths along one or more of the longitudinal and / or lateral axes, and / or to provide predetermined performance characteristics of the secondary battery.

[0065] Anode electrode structure height H E will vary depending on the energy storage device and its intended use. In general, however, the anode electrode structure typically has a height H in the range of about 0.05 mm to about 25 mm. E For example, in one embodiment, each anode electrode structure has a height H E By way of further example, in one embodiment, the height H of each anode electrode structure is in the range of about 0.05 mm to about 5 mm. Eis in the range of about 0.1 mm to about 1 mm. According to one embodiment, the anode electrode structure includes one or more first electrode members having a first height and one or more second electrode members having a second height other than the first height. In yet another embodiment, the different heights of the one or more first electrode members and the one or more second electrode members may be selected to conform to a predetermined shape of the electrode assembly, such as an electrode assembly shape having different heights along one or more of the longitudinal and / or lateral axes, and / or to provide predetermined performance characteristics of the secondary battery.

[0066] Generally, the anode electrode structure has a width W E and its height H E a length L substantially greater than each of E For example, in one embodiment, L E And, W E and H E The ratio of each of the anode assemblies to each other is at least 5:1 (i.e., L E and W E and the ratio of L to L is at least 5:1, respectively. E and H E and the ratio of L to L is at least 5:1, respectively. E And, W E and H E and each of is at least 10:1. By way of further example, in one embodiment, L E And, W E and H E and each of the ratios is at least 15:1. By way of further example, in one embodiment, L E And, W E and H E is at least 20:1 for each member of the anode assembly.

[0067] In one embodiment, the height H of the anode electrode structure E and width W E and H are at least 0.4:1, respectively. For example, in one embodiment, E and W EThe ratio of H to H is at least 2:1 for each member of the anode assembly. E and W E and H are in a ratio of at least 10:1, respectively. E and W E The ratio of H to H is at least 20:1, respectively. E and W E The ratio of H to H is generally less than 1,000:1, respectively. E and W E and H are each less than 500:1. E and W E and H are each less than 100:1. E and W E and H are each less than 10:1. E and W E The ratio of is in the range of about 2:1 to about 100:1 for each member of the anode electrode structure assembly.

[0068] Referring to FIG. 8B, each cathode electrode structure, i.e., each electrode structure 202 or counter electrode structure 204 of the cathode type, is oriented along a longitudinal axis (A CE ) measured along the length (L CE ) and width (W CE ) and length L CE and width W CE The height (H CE ) and.

[0069] Length of the cathode electrode structure L CE will vary depending on the energy storage device and its intended use. In general, however, each member of the cathode assembly typically has a length L in the range of about 5 mm to about 500 mm. CE For example, in one such embodiment, each cathode electrode structure has a length L of about 10 mm to about 250 mm. CEBy way of further example, in one such embodiment, each cathode electrode structure has a length L of about 25 mm to about 100 mm. CE According to one embodiment, the cathode electrode structure includes one or more first electrode members having a first length and one or more second electrode members having a second length other than the first length. In yet another embodiment, the different lengths of the one or more first electrode members and the one or more second electrode members can be selected to conform to a predetermined shape of the electrode assembly, such as an electrode assembly shape having different lengths along one or more of the longitudinal and / or lateral axes, and / or to provide predetermined performance characteristics of the secondary battery.

[0070] Width W of the cathode electrode structure CE will vary depending on the energy storage device and its intended use. In general, however, the cathode electrode structure typically has a width W in the range of about 0.01 mm to 2.5 mm. CE For example, in one embodiment, each cathode electrode structure has a width W CE By way of further example, in one embodiment, the width W of each cathode electrode structure is in the range of about 0.025 mm to about 2 mm. CE is in the range of about 0.05 mm to about 1 mm. According to one embodiment, the cathode electrode structure includes one or more first electrode members having a first width and one or more second electrode members having a second width other than the first width. In yet another embodiment, the different widths of the one or more first electrode members and the one or more second electrode members can be selected to conform to a predetermined shape of the electrode assembly, such as an electrode assembly shape having different widths along one or more of the longitudinal and / or lateral axes, and / or to provide predetermined performance characteristics of the secondary battery.

[0071] Cathode electrode structure height H CE will vary depending on the energy storage device and its intended use. In general, however, the cathode electrode structure typically has a height H in the range of about 0.05 mm to about 25 mm. CE For example, in one embodiment, each cathode electrode structure has a height H CEBy way of further example, in one embodiment, the height H of each cathode electrode structure is in the range of about 0.05 mm to about 5 mm. CE is in the range of about 0.1 mm to about 1 mm. According to one embodiment, the cathode electrode structure includes one or more first cathode members having a first height and one or more second cathode members having a second height other than the first height. In yet another embodiment, the different heights of the one or more first cathode members and the one or more second cathode members can be selected to conform to a predetermined shape of the electrode assembly, such as an electrode assembly shape having different heights along one or more of the longitudinal and / or lateral axes, and / or to provide predetermined performance characteristics of the secondary battery.

[0072] Generally, each cathode electrode structure has a width W CE and its height H CE Length L that is substantially larger than CE For example, in one embodiment, L CE And, W CE and H CE and L are at least 5:1, respectively, for each cathode electrode structure. CE and W CE and the ratio of L to L is at least 5:1, respectively. CE and H CE and the ratio of L to L is at least 5:1, respectively. CE And, W CE and H CE is at least 10:1 for each cathode electrode structure. CE And, W CE and H CE is at least 15:1 for each cathode electrode structure. CE And, W CE and H CE is at least 20:1 for each cathode electrode structure.

[0073] In one embodiment, the height H of the cathode electrode structure CE and width WCE and H are each at least 0.4:1. CE and W CE and H are at least 2:1, respectively, for each cathode electrode structure. CE and W CE and H are at least 10:1, respectively, for each cathode electrode structure. CE and W CE The ratio of H to H is at least 20:1 for each cathode electrode structure. CE and W CE The ratio of H to H is generally less than 1,000:1 for each member of the anode assembly. CE and W CE and H are at least 500:1, respectively, for each cathode electrode structure. CE and W CE and H are each less than 100:1. CE and W CE and H are each less than 10:1. CE and W CE The ratio of is in the range of about 2:1 to about 100:1 for each cathode electrode structure.

[0074] Returning to FIG. 2 , separator structure 205 separates electrode structure 202 from counter electrode structure 204. Separator structure 205 is made of an electrically insulating but ionically permeable separator material. The electrically insulating separator structure is designed to prevent electrical short circuits while also allowing the transport of ionic charge carriers necessary to complete the circuit during the passage of current in the electrochemical cell. In one embodiment, the electrically insulating separator structure is microporous and permeated with an electrolyte, e.g., a non-aqueous liquid electrolyte or a gel electrolyte. Alternatively, the electrically insulating separator structure can include a solid electrolyte, i.e., a solid ionic conductor, which can serve as both the separator and electrolyte in the battery. Separator structure 205 is adapted to electrically insulate each member of the electrode structure 202 assembly from each member of the counter electrode structure 204 assembly. Each separator structure 205 typically comprises a microporous separator material that can be permeated with a non-aqueous electrolyte, for example, in one embodiment, the microporous separator material comprises pores having diameters of at least 50 Å, more typically in the range of about 2,500 Å, and a porosity of about 25% to about 75%, more typically in the range of about 35% to 55%. Additionally, the microporous separator material can be permeated with a non-aqueous electrolyte to allow conduction of carrier ions between adjacent members of the electrode and counter electrode assemblies. In certain embodiments, for example, disregarding the porosity of the microporous separator material, at least 70% by volume of the electrically insulating separator material between a member of the electrode structure 110 assembly and the nearest member(s) of the counter electrode structure 112 assembly (i.e., an "adjacent pair") for ion exchange during a charge or discharge cycle is microporous separator material, or stated another way, the microporous separator material constitutes at least 70% by volume of the electrically insulating material between a member of the electrode structure 110 assembly and the nearest member of the counter electrode 112 assembly.

[0075] In one embodiment, the microporous separator material includes a particulate material and a binder, and has a porosity of at least about 20% by volume. The pores of the microporous separator material have a diameter of at least 50 Å, typically within the range of about 250-2,500 Å. The microporous separator material typically has a porosity of less than about 75%. In one embodiment, the microporous separator material has a porosity of at least about 25% by volume. In one embodiment, the microporous separator material has a porosity of about 35-55%.

[0076] Binders for microporous separator materials can be selected from a wide range of inorganic or polymeric materials. For example, in one embodiment, the binder can be an organic polymeric material such as a fluoropolymer derived from a monomer containing vinylidene fluoride, hexafluoropropylene, tetrafluoropropene, or the like. In another embodiment, the binder is a polyolefin such as polyethylene, polypropylene, or polybutene having any of a variety of molecular weight and density ranges. In another embodiment, the binder is selected from the group consisting of ethylene-diene-propene terpolymer, polystyrene, polymethyl methacrylate, polyethylene glycol, polyvinyl acetate, polyvinyl butyral, polyacetal, and polyethylene glycol diacrylate. In another embodiment, the binder is selected from the group consisting of methylcellulose, carboxymethylcellulose, styrene rubber, butadiene rubber, styrene-butadiene rubber, isoprene rubber, polyacrylamide, polyvinyl ether, polyacrylic acid, polymethacrylic acid, polyacrylonitrile, polyvinylidene fluoride polyacrylonitrile, and polyethylene oxide. In another embodiment, the binder is selected from the group consisting of acrylate, styrene, epoxy, and silicone. Other suitable binders may be selected from polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, polyethylene-co-vinyl acetate, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxymethyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, or mixtures thereof.In yet another embodiment, the binder may be selected from any of polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichloroethylene, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxymethyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polyether ether ketone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, polyethylene naphthalene, and / or combinations thereof. In another embodiment, the binder is a copolymer or blend of two or more of the foregoing polymers.

[0077] The particulate material included in the microporous separator material may also be selected from a wide range of materials. Generally, such materials have relatively low electronic and ionic conductivities at operating temperatures and do not corrode under the operating voltages of the battery electrodes or current collectors that contact the microporous separator material. For example, in one embodiment, the particulate material has a conductivity for carrier ions (e.g., lithium) of less than 1×10 S / cm. By way of further example, in one embodiment, the particulate material has a conductivity for carrier ions of less than 1×10 S / cm. By way of further example, in one embodiment, the particulate material has a conductivity for carrier ions of less than 1×10 S / cm. For example, in one embodiment, the particulate material is an inorganic material selected from the group consisting of silicates, phosphates, aluminates, aluminosilicates, and hydroxides, such as magnesium hydroxide and calcium hydroxide. Exemplary particulate materials include particulate polyethylene, polypropylene, TiO2-polymer composites, silica aerogel, fumed silica, silica gel, silica hydrogel, silica xerogel, silica sol, colloidal silica, alumina, titania, magnesia, kaolin, talc, diatomaceous earth, calcium silicate, aluminum silicate, calcium carbonate, magnesium carbonate, or combinations thereof. For example, in one embodiment, the particulate material comprises a particulate oxide or nitride, such as TiO2, SiO2, Al2O3, GeO2, BO3, Bi2O3, BaO, ZnO, ZrO2, BN, Si3N4, or Ge3N4. See, e.g., P. Arora and J. Zhang, "Battery Separators," Chemical Reviews 2004, 104, 4419-4462. Other suitable particles may include BaTiO3, Pb(Zr,Ti)O3 (PZT), Pb1-xLaxZr1-yTiyO3 (PLZT), PB(Mg3Nb2 / 3)O3-PbTiO3 (PMN-PT), hafnia (HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, YO3, Al2O3, TiO2, SiC, or mixtures thereof. In one embodiment, the particulate material has an average particle size of about 20 nm to 2 micrometers, more typically 200 nm to 1.5 micrometers.In one embodiment, the particulate material has an average particle size of about 500 nm to 1 micrometer.

[0078] In yet another embodiment, the separator structure includes a solid electrolyte 205, such as in a solid-state battery. Generally speaking, a solid electrolyte can facilitate the transport of carrier ions without the need for the addition of a liquid or gel electrolyte. According to certain embodiments, when a solid electrolyte is provided, the solid electrolyte can itself provide insulation between the electrodes and allow the passage of carrier ions therethrough, and may not require the addition of a liquid electrolyte that permeates the structure.

[0079] Generally, the electrically insulating separator material has a thickness of at least about 4 um. For example, in one embodiment, the electrically insulating separator material has a thickness of at least about 8 um. By way of further example, in one such embodiment, the electrically insulating separator material has a thickness of at least about 12 um. By way of further example, in one such embodiment, the electrically insulating separator material has a thickness of at least about 15 um. In some embodiments, the electrically insulating separator material has a thickness of up to 25 um, up to 50 um, or any other suitable thickness. However, typically, the electrically insulating separator material has a thickness of less than about 12 um, or even less than about 10 um.

[0080] Generally, the material of separator structure 205 can be selected from a wide range of materials capable of conducting carrier ions between the positive and negative active materials of the unit cells. For example, separator structure 205 can include a microporous separator material that can be permeated with a liquid non-aqueous electrolyte. Alternatively, separator structure 205 can include a gel or solid electrolyte that can conduct carrier ions between the positive and negative electrodes of the unit cells.

[0081] In one embodiment, the separator structure 205 may include a polymer-based electrolyte. Exemplary polymer electrolytes include PEO-based polymer electrolytes, polymer-ceramic composite electrolytes, polymer-ceramic composite electrolytes, and polymer-ceramic composite electrolytes.

[0082] In another embodiment, the separator structure 205 may include an oxide-based electrolyte. Exemplary oxide-based electrolytes include lithium lanthanum titanate (Li 0.34 La 0.56 TiO3), Al-doped lanthanum lithium zirconate (Li 6.24 La3Zr2Al 0.24 O 11.98 ), Ta-doped lithium lanthanum zirconate (Li 6.4 La3Zr 1.4 Ta 0.6 O 12 ), and lithium aluminum titanium phosphate (Li 1.4 Al 0.4 Ti 1.6 (PO4)3).

[0083] In another embodiment, the separator structure 205 may include a solid electrolyte. Exemplary solid electrolytes include lithium tin phosphorus sulfide (Li 10 SnP2S 12 ), lithium phosphorus sulfide (β-Li3PS4), and lithium phosphorus sulfide iodide (Li6PS5Cl 0.9 I 0.1 In some embodiments, the separator structure 205 may include a solid lithium-ion conducting ceramic, such as a lithium-loaded garnet.

[0084] In alternative embodiments, the particulate materials comprised by the microporous separator material may be bound together by techniques such as sintering, bonding, curing, etc., while maintaining the desired porosity for electrolyte infiltration to provide ionic conductivity for battery function.

[0085] Some embodiments include an electrolyte that can be any of an organic liquid electrolyte, an inorganic liquid electrolyte, an aqueous electrolyte, a non-aqueous electrolyte, a solid polymer electrolyte, a solid ceramic electrolyte, a solid glass electrolyte, a garnet electrolyte, a gel polymer electrolyte, an inorganic solid electrolyte, a fused-type inorganic electrolyte, etc. Other arrangements and / or configurations of the separator structure, with or without a liquid electrolyte, can also be provided. In one embodiment, the solid electrolyte can include a ceramic or glass material that can provide electrical insulation while also conducting carrier ions therethrough. Examples of ion-conducting materials can include garnet materials, sulfide glasses, lithium-ion conducting glass ceramics, or phosphate ceramic materials. In one embodiment, the solid polymer electrolyte can include any of polyethylene oxide (PEO)-based, polyvinyl acetate (PVA)-based, polyethyleneimine (PEI)-based, polyvinylidene fluoride (PVDF)-based, polyacrylonitrile (PAN)-based, LiPON (lithium phosphate nitride), and polymethyl methacrylate (PMMA)-based polymers, or copolymers thereof. In another embodiment, a sulfide-based solid electrolyte may be provided, such as a sulfide-based solid electrolyte comprising at least one of lithium and / or phosphorus, such as at least one of Li2S and P2S5, and / or other sulfides, such as SiS2, GeS2, Li3PS4, Li4P2S7, Li4SiS4, Li2S-P2S5, and 50Li4SiO4.50Li3BO3, and / or B2S3.Still other embodiments of the solid electrolyte include LiN, LiI, LiN1, LiN-LiI-LiOH, LiSiO, LiSiO-LiI-LiOH, LiSiS, LiSiO, LiSiO-LiI-LiOH, and LiPO-LiS-SiS, LiS-P2S, LiS-P2S-L4SiO, LiS-GaS-GeS, LiS-SbS-GeS, LiS-Ge-P0.75S, (La,Li)TiO(LLTO). Lithium (Li) nitrides, halides, and sulfates may include, for example, Li6La2CaTa2O12, Li6La2ANb2O12 (A=Ca, Sr), Li2Nd3TeSbO12, Li3BO2.5N0.5, Li9SiAlO8, Li1+xAlxGe2-x(PO4)3(LAGP), Li1+xAlxTi2-x(PO4)3(LATP), Li1+xTi2-xAlxSiy(PO4)3-y, LiAlxZr2-x(PO4)3, LiTixZr2-x(PO4)3. Still other embodiments of the solid electrolyte may include garnet materials, such as those described in U.S. Pat. No. 10,361,455, which is incorporated herein in its entirety. In one embodiment, the garnet solid electrolyte is a nesosilicate having the general formula XY(SiO), where X can be a divalent cation such as Ca, Mg, Fe, or Mn, or Y can be a trivalent cation such as Al, Fe, or Cr.

[0086] In some embodiments, the separator structure includes a microporous separator material that is permeated with a non-aqueous electrolyte suitable for use as a secondary battery electrolyte. Typically, the non-aqueous electrolyte includes a lithium salt and / or mixture of salts dissolved in an organic solvent and / or solvent mixture. Exemplary lithium salts include inorganic lithium salts such as LiClO, LiBF, LiPF, LiAsF, LiCl, and LiBr, and organic lithium salts such as LiB(CH), LiN(SOCF), LiN(SOCF), LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF, LiNSOCF. As yet another example, the electrolyte may include sodium ions dissolved therein, such as, for example, any one or more of NaClO4, NaPF6, NaBF4, NaCF3SO3, NaN(CF3SO2)2, NaN(C2F5SO2)2, NaC(CF3SO2)3. Salts of magnesium and / or potassium may be provided as well. For example, magnesium salts such as magnesium chloride (MgCl2), magnesium bromide (MgBr2), or magnesium iodide (MgI2) may be provided, and / or may be provided with magnesium perchlorate (Mg(ClO4)2), magnesium nitrate (Mg(NO3)2), magnesium sulfate (MgSO4), magnesium tetrafluoroborate (Mg(BF4)2), magnesium tetraphenylborate (Mg(B(C6H5)4)2, magnesium hexafluorophosphate (Mg(PF6)2), magnesium hexafluoroarsenate (Mg(AsF6)2), perfluoroalanine (Mg(PF6)2), magnesium hexafluoroarsenate (Mg(AsF6)2), magnesium hexafluoroarsenate (Mg(PF ... A magnesium salt may be provided which may be at least one selected from the group consisting of magnesium alkylsulfonate ((Mg(Rf1SO3)2) (wherein Rf1 is a perfluoroalkyl group), magnesium perfluoroalkylsulfonylimide (Mg((Rf2SO2)2N)2 (wherein Rf2 is a perfluoroalkyl group), and magnesium hexaalkyldisilazide ((Mg(HRDS)2) (wherein R is an alkyl group). Organic solvents that dissolve the lithium salt include cyclic esters, chain esters, cyclic ethers, and chain ethers.Specific examples of cyclic esters include propylene carbonate, ethylene carbonate, butylene carbonate, γ-butyrolactone, vinylene carbonate, 2-methyl-γ-butyrolactone, acetyl-γ-butyrolactone, and γ-valerolactone.Specific examples of chain esters include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dipropyl carbonate, methylethyl carbonate, methylbutyl carbonate, methylpropyl carbonate, ethylbutyl carbonate, ethylpropyl carbonate, butylpropyl carbonate, alkyl propionate, dialkyl malonate, and alkyl acetate.Specific examples of cyclic ethers include tetrahydrofuran, alkyltetrahydrofuran, dialkyltetrahydrofuran, alkoxytetrahydrofuran, dialkoxytetrahydrofuran, 1,3-dioxolane, alkyl-1,3-dioxolane, and 1,4-dioxolane. Specific examples of chain ethers include 1,2-dimethoxyethane, 1,2-diethoxyethane, diethyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, and tetraethylene glycol dialkyl ether.

[0087] In one embodiment, the microporous separator of the separator structure can be impregnated with a non-aqueous organic electrolyte comprising a mixture of a lithium salt and a high purity organic solvent. Additionally, the electrolyte can be a polymer using a polymer electrolyte or a solid electrolyte.

[0088] The electrode bus bar 208 is a cathode bus bar when the electrode structure 202 is of a cathode type, and is an anode bus bar when the electrode structure 202 is of an anode type. Similarly, the counter electrode bus bar is a cathode bus bar when the counter electrode structure 204 is of a cathode type, and is an anode bus bar when the counter electrode structure 204 is of an anode type. In example embodiments, the anode type bus bar is a copper bus bar, and the cathode type bus bar is an aluminum bus bar. In other embodiments, the electrode bus bar 208 and the counter electrode bus bar 210 can be any suitable conductive material that enables the electrode assembly 200 to function as described herein.

[0089] The counter electrode structure 204, and more specifically, the counter electrode current collector 218, is directly connected to the counter electrode bus bar 210. That is, the counter electrode current collector 218 is welded, soldered, or glued to the counter electrode bus bar 210 without any components electrically or physically positioned therebetween. The welding may be performed using a laser welder, friction welding, ultrasonic welding, or any suitable welding method for welding the counter electrode bus bar 210 to the counter electrode collector 218.

[0090] 3A and 3B show an example of a technique for connection between one of the counter electrode current collectors 218 and the counter electrode bus bar 210. FIG. 3A is a view of an end portion of one of the counter electrode current collectors 218. The end of the counter electrode current collector 218 includes a slot 300 sized and shaped to receive the counter electrode bus bar 210. A portion 302 of the counter electrode current collector 218 extends past the slot 300. The counter electrode bus bar 210 is inserted through the slot 300, as shown in FIG. 3B, and the portion 302 of the counter electrode current collector 218 is bent up to contact the counter electrode bus bar 210. The portion 302 of the counter electrode current collector 218 that contacts the counter electrode bus bar 210 is then welded to the counter electrode bus bar 210.

[0091] 17 shows an example of another technique for connection between one of the counter electrode current collectors 218 and the counter electrode bus bar 210. In this example, the counter electrode current collector 218 does not include the slot 300. A portion 1700 of the counter electrode current collector 218 is bent at approximately a 90-degree angle, and the counter electrode bus bar 210 is positioned over the portion 1700. The counter electrode bus bar 210 is then attached directly to the portion 1700 of the counter electrode current collector 218, such as by gluing, welding, soldering, or using any other suitable technique for joining the counter electrode current collector 218 to the counter electrode bus bar 210.

[0092] Returning to FIG. 2 , each member of the current limiter 206 assembly is electrically connected between a different electrode current collector 214 and electrode bus bar 208. The current limiters 206 are configured to limit the current that can flow through the electrode current collectors 214 and, accordingly, through the electrode structure 202 to which the electrode current collectors 214 are connected. Thus, for example, when a short circuit is formed between one of the electrode current collectors 214 and one of the counter electrode current collectors 218, the current limiters 206 limit the amount of current that can flow from the other electrode and counter electrode of the electrode assembly, thereby limiting the temperature experienced by the electrode assembly 200 and preventing thermal runaway. Specifically, the current limiters 206 limit the amount of current that can be conducted through a unit cell during discharge of the electrode assembly when an electrical short circuit exists between the electrode and counter electrode of the unit cell, preventing a current through a member of the unit cell assembly that would induce thermal runaway of a member of the unit cell assembly (sometimes referred to herein as I tr or I L The current limiter limits I to a value I less than the maximum current (referred to as I). The current limiter provides a soft landing for the battery in the event of a short circuit. The current limiter continues to allow a non-zero level of current to flow in the event of a short circuit, but limits that current to below a level that would induce thermal runaway. This current continues to flow until the battery is discharged and the risk of thermal runaway is eliminated.

[0093] Current limiter 206 is a resistive current limiter. Current limiter 206 has a non-zero resistance within the normal operating temperature range of electrode assembly 200. In one example, the normal operating temperature is minus 20°C to 80°C. In other embodiments, the normal operating temperature is minus 40°C to 85°C, minus 40°C to 150°C, or any other suitable range of normal operating temperatures. The resistance is such that current limiter 206 limits the current that can pass through any unit cell and prevents the current from reaching a level that could cause catastrophic failure or any other maximum current level determined for other performance or abuse tolerance reasons as determined during battery design. In some embodiments, current limiter 206 does not rely on a fuse or any PTC characteristic of a resistive material. That is, while current limiter 206 may exhibit a PTC, a PTC is not required for current limiter 206 to function as described herein. Rather, in such embodiments, the resistance of the current limiter 206 over the normal operating temperature range of the electrode assembly 200 is sufficient to limit the current. In some embodiments, the resistance may increase or decrease over the normal range of operating temperatures (i.e., the current limiter may have a negative temperature coefficient). In some embodiments, the current limiter has a resistance over the normal range of operating temperatures, and the resistance further increases above a temperature threshold or target temperature.

[0094] Each current limiter 206 is electrically in series with the electrode current collector 214 to which it is attached. Thus, the resistance of each current limiter 206 and its associated electrode structure 202 is increased by adding the resistance of the associated electrode structure 202 and the resistance of its attached current limiter 206. Adding resistance to a battery is traditionally not recommended because the added resistance increases the losses the battery experiences as current flows into (charging) and out of (discharging) the electrode structure 202. However, because the electrode current collectors 214 are all connected in parallel (electrically in parallel) to the electrode bus bar 208, the increase in total resistance seen by the electrode bus bar 208 is much smaller than the resistance of each individual current limiter 206. Furthermore, the resistance of the current limiters 206 of the present disclosure is selected to be small enough to have a limited voltage drop across the current limiter 206, thereby having limited power loss. In an example embodiment, the resistance of the current limiters is selected to have a drop of 20 mV or less across each of the current limiters 206 during charging or discharging at a 1 C rate to limit losses during normal operation while still protecting the battery during a short circuit.

[0095] In the example embodiment, each individual unit cell, i.e., each pair of one electrode structure 202 and one counter electrode structure 204 without the current limiter 206, has a relatively small size (compared to a thin-film battery), a relatively low capacity, and a sufficiently high internal resistance so that the current through an isolated unit cell cannot reach a level sufficient to cause thermal runaway and catastrophic failure, even when there is a short circuit between the electrode structure 202 and the counter electrode structure 204 of the unit cell. However, when multiple unit cells are connected in parallel to a bus bar, such as the electrode bus bar 208, within an electrode assembly, such as the electrode assembly 200, all of the unit cells supply current to the unit cell that has a short circuit therein. Under such circumstances, without the current limiter 206, sufficient current could pass through the shorted unit cell to cause thermal runaway and catastrophic failure of the electrode assembly 200 and the battery containing it. Adding the current limiter 206 effectively increases the resistance of the unit cell. For a fixed voltage V of the unit cell, increasing the resistance results in a corresponding decrease in maximum current, according to Ohm's law.

[0096] More specifically, the volume of the electrode assembly 200 is subdivided into a number (n) of electrode unit cells, each of which contains one electrode structure 202 and one counter electrode structure 204. Each unit cell generates a voltage (V). Each individual electrode unit cell has its own characteristic resistance (R ) that is a function of the conductivity and geometry of the unit cell assembly. bl Each individual unit cell has a forced internal short circuit (FISC) resistance (R s ) across a short circuit

number

number

[0097] When the electrode structure 202 and counter electrode structure 204 of each unit cell are connected in parallel to their respective bus bars 208, 210, all unit cells are affected (i.e., shorted) by the FISC of the individual unit cells.

number

number

[0098] The current limiters 206 are added, each of which has a non-zero resistance (R cld ), resulting in the FISC power for the shorted unit cell being given by:

number

number

number

[0099] The required resistance of the current limiter 206 may also be considered in terms of the resistance necessary to limit the current through a shorted unit cell below a threshold current sufficient to cause thermal runaway. Thus, by knowing the voltage generated by each unit cell, the capacity of each unit cell, the internal resistance of each unit cell, the resistance of the electrode bus bar 208, and the resistance of the counter electrode bus bar 210, one can calculate the resistance of the current limiter 206 that will limit the current through a shorted unit cell below the threshold current required to cause thermal runaway. While the threshold current required to cause thermal runaway may vary somewhat depending on the configuration of the electrode assembly and the capacity of the individual unit cells, for similarly configured electrode assemblies, the threshold current remains relatively constant. In an example embodiment, the threshold current is approximately 8 amperes. In other embodiments, the threshold current may be approximately 4 amperes, approximately 8 amperes, approximately 10 amperes, approximately 12 amperes, or between 8 amperes and 12 amperes. The required resistance of the current limiter 206 will vary depending on the specific configuration of the battery and its components. For similar electrode assemblies, the resistance required to limit the current below a threshold current generally increases as the capacitance of the individual unit cells increases.

[0100] More specifically, the capacity of a traditional stack battery cell is subdivided into the number (N) of electrode unit cells where each positive and negative electrode forms a voltage (V). The number of unit cells in a complete stack is represented by an uppercase N, while the number of unit cells as a variable is represented by a lowercase n, for example, when performing replicate assays with different numbers of unit cells. Each individual electrode unit cell has its own characteristic resistance (R), which is a function of the conductivity and geometry of the unit cell assembly. bl Each individual unit cell has a forced internal short circuit (FISC) resistance (R s ) across the current (I bl ) can be discharged. The FISC current of an individual unit cell is given by:

number

number

[0101] In at least some cases, the characteristic resistance of an individual unit cell determines the current that an individual unit cell can discharge across the FISC beyond the thermal runaway current (I tr ), which is a current that can be sufficient to cause self-accelerating exothermic decomposition and thermal runaway. When multiple electrode unit cells are interconnected through a shared terminal, the discharge current across the FISC of each affected unit cell is the thermal runaway current (I tr ) and makes it increasingly likely to result in catastrophic cell failure.

[0102] The resistor of each current limiter 206 limits the current that may pass through any individual unit cell to a thermal runaway current (I tr The resistance of each current limiter (R cld ) is determined as the resistance that satisfies

number

number

[0103] The resistance of an individual unit cell is determined by the impedance at the top of the live part, further considering the resistance of the terminals calculated based on the number of unit cell subdivisions and their material composition and geometry. For an example using 20 kHz impedance, the resistance of the unit cell is given by:

number

[0104] In an example embodiment, the thermal runaway current (I tr ) is determined by performing a worst-case forced internal short circuit assay described below. In other embodiments, the thermal runaway current (I tr ) can be estimated, derived from simulations, determined using different assays, or arrived at through any other suitable method. However, once determined, the thermal runaway current (I tr ) in equation (6) to satisfy the inequality, cld ) is determined. cldBy choosing to provide a thermal runaway current (I), the current limiter 206 limits the current through any unit cell to a thermal runaway current (I tr ) effectively limiting

[0105] In an example embodiment, the resistance of each current limiter 206 at 25 degrees Celsius (°C) is approximately 0.25 ohms (Ω), limiting short-circuit current to less than approximately 8 amps. This results in a voltage drop of 20 mV or less across each current limiter 206 when the electrode assembly 200 is charging or discharging at a 1 C rate. In other embodiments, the resistance of each current limiter 206 is between 0.25 Ω and 2.5 Ω. In some embodiments, the resistance of each current limiter 206 is between 0.1 Ω and 1.5 Ω. These ranges provide a range of resistance that balances the need to limit current during a short circuit while also limiting losses during normal operation of the battery. The exact value within the range, and which range to select, can be selected based on the voltage, capacity, or other characteristics of a particular battery. More generally, in some embodiments, the resistance of each current limiter 206 is determined by selecting a resistor that produces a voltage drop of less than 0.5 volts when the electrode assembly 200 (or individual unit cell) is charging or discharging at a 1 C rate when discharged from a maximum of charge (TOC) condition. That is, the current at a 1 C rate multiplied by the resistance of the current limiter 206 is less than 0.5 volts to minimize losses during normal operation while still adequately limiting the current during a short circuit.

[0106] The current limiter 206, in the example embodiment, is positioned on the electrode bus bar 208. The current limiter is physically positioned between the electrode current collector 214 and the electrode bus bar 208. In other embodiments, the current limiter 206 may be electrically coupled between the electrode current collector 214 and the electrode bus bar 208, but may also be physically coupled outside of the connection between the electrode current collector 214 and the electrode bus bar 208.

[0107] In the embodiments described herein, the current limiter 206 has a measurable resistance at room / normal operating temperature sufficient to prevent thermal runaway during the initiation of a short circuit without a time lag. As the temperature of the current limiter 206 increases during a short circuit, the resistance of the current limiter 206 increases above a transition temperature, thereby providing additional protection during a short circuit. For example, the current limiter 206 may at least partially melt, expand, and / or partially detach from the electrode bus bar 208 and / or electrode current collector 214 above the transition temperature, thereby increasing the resistance of the current limiter 206 and providing additional protection from a short circuit.

[0108] 2 , interfaces 220, 222 are formed between electrode current collector 214, electrode bus bar 208, and current limiter 206. Specifically, interface 220 is formed between electrode current collector 214 and current limiter 206, and interface 222 is formed between electrode bus bar 208 and current limiter 206. Current limiter 206 adheres to electrode current collector 214 and electrode bus bar 208 at interfaces 220, 222, respectively. For example, during normal operating currents and temperatures of current limiter 206, interfaces 220, 220 form mechanical and electrical connections between current limiter 206, electrode current collector 214, and electrode bus bar 208, respectively.

[0109] More specifically, the current limiter 206 adheres to the electrode current collector 214 and the electrode bus bar 208 at interfaces 220, 222, respectively, when the current limiter 206 is below a transition temperature. To specifically select a transition temperature at which the current limiter 206 begins to melt and reduces adhesion to the electrode current collector 214 and the electrode bus bar 208 at interfaces 220, 222, the transition temperature can be adjusted by modifying one or more design parameters of the current limiter 206 prior to assembling the electrode assembly 200. For example, the chemical composition of the current limiter 206, the additives included in the current limiter 206, the thickness of the current limiter 206, etc. can be modified to adjust the transition temperature.

[0110] The transition temperature may be the minimum expected temperature of the current limiter 206 during abnormal operation of the electrode assembly 200. The abnormal operation of the electrode assembly 200 may be, for example, exceeding the rated current and / or temperature of the electrode assembly 200. When the current limiter 206 is at or above the transition temperature, the current limiter 206 at least partially melts, reducing adhesion between the current limiter 206 and one or more of the electrode current collector 214 and the electrode bus bar 208 at their respective interfaces 220 and 222. This reduced adhesion results in increased resistance. Specifically, reduced adhesion occurs when the current limiter 206 is at or above the transition temperature compared to when the current limiter 206 is below the transition temperature. The reduced adhesion may include the creation of voids at the interfaces 220 and 222, partial delamination at the interfaces 220 and 222, a reduction in contact surface area at the interfaces 220 and 222, a reduction in mechanical strength at the interfaces 220 and 222, etc. Generally, an increase in resistance between the electrode bus bar 208 and the electrode current collector 214 can be attributed to an increase in resistance at the interfaces 220, 222. Each of the interfaces 220, 222 has a contact resistance, the electrode current collector 214 has a resistance, the electrode bus bar 208 has a resistance, and the current limiter 206 has a resistance, each of which is in series. By reducing the adhesion at the interfaces 220, 222, one or more of the contact resistances at the interfaces 220, 222 increases, resulting in an overall increase in the series resistance through the electrode current collector 214 and the electrode bus bar 208, regardless of any change in the resistance through the current limiter 206.

[0111] In other embodiments, the transition temperature may be selected to be an amount above the minimum expected temperature of the current limiter 206 during abnormal operation of the electrode assembly 200 to allow slight abnormal operation to occur for a limited period of time without melting the current limiter 206.

[0112] For example, one or more of the current limiters 206 may at least partially melt in response to an electrical short between the electrode structure 202 and the counter electrode structure 204 of a unit cell, such as an electrical short between the electrode active material 212 and the counter electrode active material 216 of a unit cell (or between the electrode current collector 214 and the counter electrode current collector 218). A higher-than-normal current flowing through the electrode current collector 214 and the current limiter 206 associated with the shorted unit cell heats the current limiter 206 to a temperature above its transition temperature, causing the current limiter 206 associated with the shorted unit cell to at least partially melt. An electrical short between the electrode active material 212 and the counter electrode active material 216 may occur due to intrusion by an external conductive object, for example, due to one or more electrically conductive dendrites extending through the separator structure 205, the inclusion of an external conductive material within the assembly, or any other occurrence that electrically connects the electrode active material 212 and the counter electrode active material 216.

[0113] When the current limiter 206 at least partially melts, the adhesion between the current limiter 206 and the electrode current collector 214 at interface 220 is reduced and / or the adhesion between the current limiter 206 and the electrode bus bar 208 at interface 222 is reduced. The reduced adhesion increases the electrical resistance between the electrode current collector 214 and the electrode bus bar 208. The increased electrical resistance limits the amount of current that can flow between the electrode current collector 214 and the electrode bus bar through the at least partially melted current limiter 206, thereby limiting the temperature increase and preventing thermal runaway from occurring.

[0114] In some embodiments, the current limiter 206 includes an adhesive polymer and a conductive material suspended in the polymer. In these embodiments, for example, the polymer at least partially melts above a transition temperature to reduce the adhesion between the current limiter 206 and the electrode current collector 214 at interface 220 and / or the adhesion between the current limiter 206 and the electrode bus bar 208 at interface 222, thereby increasing the electrical resistance between the electrode current collector 214 and the electrode bus bar 208. In some embodiments, the polymer includes an electrical insulator.

[0115] At least partially melting the polymer, in one embodiment, increases the bulk resistivity of current limiter 206, increasing the electrical resistance between electrode current collector 214 and electrode bus bar 208. In another embodiment, at least partially melting the polymer increases the interfacial resistance between current limiter 206 and electrode current collector 214 at interface 220 and / or increases the interfacial resistance between current limiter 206 and electrode bus bar 208 at interface 222, increasing the electrical resistance between electrode current collector 214 and electrode bus bar 208.

[0116] In some embodiments, at least partially melting the polymer modifies the electrical resistance of the current limiter 206 in other ways. In one embodiment, at least partially melting the polymer reduces the contact of the conductive material within the current limiter 206, thereby increasing the volume resistivity of the current limiter 206 and increasing the electrical resistance between the electrode current collector 214 and the electrode bus bar 208. In another embodiment, at least partially melting the polymer may cause the polymer and / or portions of the polymer to flow and / or be engulfed in the region proximate the interface 220 and / or to flow and / or be engulfed in the region proximate the interface 222. The polymer flowing in such regions positions more polymer between the conductive material within the current limiter 206 and the interfaces 220, 222, thereby increasing the electrical resistance between the electrode current collector 214 and the electrode bus bar 208.

[0117] In some embodiments, the current limiter 206 at least partially carbonizes at or above the transition temperature, which increases the electrical resistance between the electrode current collector 214 and the electrode bus bar 208. In one embodiment, carbonizing the current limiter 206 forms an electrical insulating layer between the current limiter 206 and the electrode current collector 214 at interface 220 and / or forms an electrical insulating layer between the current limiter 206 and the electrode bus bar 208 at interface 222, depending on the location of the carbonization.

[0118] In some embodiments, at least partially melting the current limiter 206 at least partially decouples the current limiter 206 from the electrode current collector 214 at interface 220 and / or the current limiter 206 from the electrode bus bar 208 at interface 222, thereby increasing the electrical resistance between the electrode current collector 214 and the electrode bus bar 208. In some embodiments, this decoupling is not reversible. For example, even if the temperature of the current limiter 206 is below the transition temperature, the current limiter 206 may remain at least partially decoupled from the electrode current collector 214 and / or the electrode bus bar 208 at interfaces 220, 222, respectively. In this example, the electrode assembly 200 may continue to operate with a reduced energy capacity and / or a reduced current handling capacity. That is, a unit cell that has experienced a fault event that at least partially melts its current limiter 206 and permanently disconnects it from its current collector 214 and / or electrode bus bar 208 is inoperable to conduct current to the electrode bus bar, while the remaining unit cells (which did not experience the fault that melted their current limiters 206) can continue to conduct current to the electrode bus bar 208.

[0119] In some embodiments, the current limiter 206 changes volume based on a change in temperature of the current limiter 206. In one embodiment, the current limiter 206 includes a polymer material and at least one phase change element that varies the volume of the current limiter 206 based on temperature. In this embodiment, the phase change element facilitates a volume expansion of the current limiter 206 based on a change in temperature of the current limiter 206, thereby reducing adhesion between the current limiter 206 and the electrode current collector 214 at interface 220 and / or reducing adhesion between the current limiter 206 and the electrode bus bar 208 at interface 222, increasing the electrical resistance between the electrode current collector 214 and the electrode bus bar 208.

[0120] As discussed above, the current limiter 206 adheres to the electrode current collector 214 and the electrode bus bar 208 at interfaces 220, 222, respectively, when the current limiter 206 is below the transition temperature. To specifically select the transition temperature at which the current limiter 206 begins to change volume and / or at which the current limiter 206 changes volume by a threshold amount, the transition temperature can be adjusted by modifying one or more design parameters of the current limiter 206 prior to assembling the electrode assembly 200.

[0121] For example, the transition temperature may be the minimum expected temperature of the current limiter 206 during abnormal operation of the electrode assembly 200. The abnormal operation of the electrode assembly 200 may be, for example, exceeding the rated current and / or temperature of the electrode assembly 200. When the current limiter 206 is at or above the transition temperature, the current limiter 206 reduces adhesion between the current limiter 206 and one or more of the electrode current collector 214 and the electrode bus bar 208 at interfaces 220 and 222, respectively, thereby increasing the electrical resistance between the electrode current collector 214 and the electrode bus bar 208. This reduced adhesion results in an increase in resistance. Specifically, adhesion is reduced when the current limiter 206 is at or above the transition temperature compared to when the current limiter 206 is below the transition temperature. In other embodiments, the transition temperature may be selected to be an amount above the minimum expected temperature of the current limiter 206 during abnormal operation of the electrode assembly 200 to allow for slight abnormal operation to occur for a limited period of time without changing the volume of the current limiter 206.

[0122] For example, one or more of the current limiters 206 may volumetrically expand in response to an electrical short between the electrode structure 202 and the counter electrode structure 204 of a unit cell, such as an electrical short between the electrode active material 212 and the counter electrode active material 216 (or between the electrode current collector 214 and the counter electrode current collector 218 of a unit cell). A higher-than-normal current flowing through the electrode current collector 214 and current limiter 206 associated with the shorted unit cell heats the current limiter 206 to a temperature above its transition temperature, causing the current limiter 206 associated with the shorted unit cell to volumetrically expand. An electrical short between the electrode active material 212 and the counter electrode active material 216 may occur due to intrusion by an external conductive object, for example, due to one or more electrically conductive dendrites extending through the separator structure 205, the inclusion of an external conductive material within the electrode assembly 200, or any other occurrence that electrically connects the electrode active material 212 and the counter electrode active material 216.

[0123] As the current limiter 206 volumetrically expands, the adhesion between the current limiter 206 and the electrode current collector 214 at interface 220 decreases and / or the adhesion between the current limiter 206 and the electrode bus bar 208 decreases. The reduced adhesion increases the electrical resistance between the electrode current collector 214 and the electrode bus bar 208. The increased electrical resistance limits the amount of current that can flow between the electrode current collector 214 and the electrode bus bar through the expanded current limiter 206, thereby limiting the temperature increase and preventing thermal runaway from occurring.

[0124] In one embodiment, below the transition temperature, the current limiter 206 adheres to the electrode current collector 214 and the electrode bus bar 208 at interfaces 220, 222, respectively. Below the transition temperature, the current limiter 206 may have a substantially constant first volume. At or above the transition temperature, the current limiter 206 expands from the first volume toward a second volume, thereby reducing the adhesion between the current limiter 206 and the electrode current collector 214 at interface 220 and / or reducing the adhesion between the current limiter 206 and the electrode bus bar 208 at interface 222, increasing the resistance between the electrode current collector 214 and the electrode bus bar 208.

[0125] In some embodiments, increasing the volume of the current limiter 206 at least partially decouples the current limiter 206 from the electrode current collector 214 at interface 220 and / or at least partially decouples the current limiter 206 from the electrode bus bar 208 at interface 222, thereby increasing the electrical resistance between the electrode current collector 214 and the electrode bus bar 208. In some embodiments, this decoupling is not reversible. For example, even if the temperature of the current limiter 206 is below the transition temperature, the current limiter 206 may remain at least partially decoupled from the electrode current collector 214 and / or the electrode bus bar 208 at interfaces 220, 222, respectively. In this example, the electrode assembly 200 may continue to operate with a reduced energy capacity and / or a reduced current handling capacity. That is, a unit cell that has experienced a fault event that at least partially melts its current limiter 206 and permanently disconnects it from its current collector 214 and / or electrode bus bar 208 is inoperable to conduct current to the electrode bus bar, while the remaining unit cells (which did not experience the fault that melted their current limiters 206) can continue to conduct current to the electrode bus bar 208.

[0126] Some non-limiting embodiments of the phase change element include one or more of expandable graphite, sodium carbonate, and calcium carbonate. In other embodiments, the phase change element includes any material that operates to modify the volume of the current limiter 206 based on temperature.

[0127] In some embodiments, the electrode current collector 214 and / or the electrode bus bar 208 at least partially decouple from the current limiter 206 at or above a transition temperature. In this embodiment, the electrode current collector 214 and the electrode bus bar 208 adhere to the current limiter 206 at interfaces 220 and 222, respectively, below the transition temperature. However, above the transition temperature, the electrode current collector 214 and / or the electrode bus bar 208 at least partially decouple from the current collector 206 at interfaces 220 and 222, respectively. To specifically select the transition temperature at which the electrode current collector 214 and / or the electrode bus bar 208 at least partially decouple from the current limiter 206, the transition temperature can be adjusted by modifying one or more design parameters of the electrode current collector 214 and / or the electrode bus bar 208 prior to assembling the electrode assembly 200. In some embodiments, the electrode bus bar 208 and / or the electrode collector 214 comprises one or more of a bimetal, a trimetal, and / or nitinol.

[0128] At least partial decoupling at interface 220 and / or interface 222 may result, for example, due to thermal stresses applied to electrode current collector 214 by current limiter 206 and / or due to thermal stresses applied to electrode bus bar 208 by current limiter 206. For example, Joule heating of electrode bus bar 208 by one or more of current limiters 206 may bend, distort, or deform the electrode bus bar, thereby at least partially decoupling current limiter 206 from interface 220 and / or interface 222. In another example, Joule heating of electrode current collector 214 by current limiter 206 may bend, distort, or deform electrode current collector 214, thereby at least partially decoupling current limiter 206 from interface 220 and / or interface 222. In another example, heating of the electrode current collector 214 and / or the electrode bus bar 208 may cause at least partial debonding at the interfaces 220, 222, respectively.

[0129] For example, the transition temperature may be the minimum expected temperature of the electrode bus bar 208 and / or the electrode current collector 214 during abnormal operation of the electrode assembly 200. The abnormal operation of the electrode assembly 200 may be, for example, exceeding the rated current and / or temperature of the electrode assembly 200.

[0130] A partial disconnection can increase the resistance between one or more of the electrode current collectors 214 and the electrode bus bar 208, while a complete disconnection can create an open circuit between one or more of the electrode current collectors 214 and the electrode bus bar 208.

[0131] For example, at least partial decoupling may occur in response to an electrical short between the electrode structure 202 and the counter electrode structure 204 of a unit cell, such as an electrical short between the electrode active material 212 and the counter electrode active material 216 (or between the electrode current collector 214 and the counter electrode current collector 218 of a unit cell). A higher-than-normal current flowing through the electrode current collector 214 and current limiter 206 associated with the shorted unit cell heats the current limiter 206 to a temperature above its transition temperature, at least partially decoupling the current limiter 206 associated with the shorted unit cell. An electrical short between the electrode active material 212 and the counter electrode active material 216 may occur due to intrusion by an external conductive object, for example, due to one or more electrically conductive dendrites extending through the separator structure 205, the inclusion of an external conductive material within the electrode assembly 200, or any other occurrence that electrically connects the electrode active material 212 and the counter electrode active material 216.

[0132] When the current limiter 206 is at least partially decoupled, the adhesion between the current limiter 206 and the electrode current collector 214 at interface 220 is reduced and / or the adhesion between the current limiter 206 and the electrode bus bar 208 at interface 222 is reduced. The reduced adhesion increases the electrical resistance between the electrode current collector 214 and the electrode bus bar 208. The increased electrical resistance limits the amount of current that can flow between the electrode current collector 214 and the electrode bus bar through the at least partially decoupled current limiter 206, thereby limiting the temperature increase and preventing thermal runaway from occurring.

[0133] In some embodiments, the at least partial decoupling is not reversible. For example, the current limiter 206 may remain at least partially decoupled from the electrode current collector 214 and / or the electrode bus bar 208 at interfaces 220, 222, respectively, even when the temperature of the electrode current collector 214 and / or the electrode bus bar 208 is below the transition temperature. In this example, the electrode assembly 200 may continue to operate with a reduced energy capacity and / or a reduced current handling capacity. In other embodiments, the at least partial decoupling includes electrical decoupling between the electrode bus bar 208 and the electrode current collector 214.

[0134] Each unit cell of the collection of unit cells of the electrode assembly 200 has an ionic resistance (also referred to as internal resistance). In some embodiments, the current limiter 206 at least partially melts upon formation of an electrical short within a member of the collection of unit cells when the electrical short has an electrical resistance less than the ionic resistance of the member of the collection of unit cells in which the electrical short is formed. In embodiments in which the current limiter 206 includes at least one phase change element that expands the volume of the current limiter 206 at or above the transition temperature, the current limiter 206 expands from a first volume below the transition temperature to a second volume at or above the transition temperature upon formation of an electrical short within a member of the collection of unit cells when the electrical short has an electrical resistance less than the ionic resistance of the member of the collection of unit cells in which the electrical short is formed. In some embodiments, at least one of electrode current collector 214 and electrode bus bar 208 is at least partially decoupled from current limiter 206 upon formation of an electrical short within a member of the unit cell assembly when the electrical short has an electrical resistance less than the ionic resistance of the member of the unit cell assembly in which the electrical short is formed. In other embodiments, at least one of electrode current collector 214 and electrode bus bar 208 is electrically decoupled from current limiter 206 upon formation of an electrical short within a member of the unit cell assembly when the electrical short has an electrical resistance less than the ionic resistance of the member of the unit cell assembly in which the electrical short is formed.

[0135] Each unit cell of the collection of unit cells of the electrode assembly 200 has a capacitance (C), and the current limiter 206 at least partially melts upon passage of a current therethrough at a current of at least x times C. In embodiments in which the current limiter 206 includes at least one phase change element that expands the volume of the current limiter 206 at or above the transition temperature, the current limiter 206 expands from a first volume below the transition temperature to a second volume at or above the transition temperature upon passage of a current therethrough at a current of at least x times C. In other embodiments, at least one of the electrode current collector 214 and the electrode bus bar 208 at least partially decouples from the current limiter 206 upon passage of a current therethrough at a current of at least x times C. In other embodiments, at least one of the electrode current collector 214 and the electrode bus bar 208 is electrically decoupled from the current limiter 206 upon passage of a current through the current limiter 206 of at least x times C. In some embodiments, x is from about 1 C to about 15. In one embodiment, x is about 1. In another embodiment, x is about 2. In another embodiment, x is about 3. In another embodiment, x is about 4. In another embodiment, x is about 5. In another embodiment, x is about 6. In another embodiment, x is about 7. In another embodiment, x is about 8. In another embodiment, x is about 9. In another embodiment, x is about 10. In another embodiment, x is about 11. In another embodiment, x is about 12. In another embodiment, x is about 13. In another embodiment, x is about 14. In another embodiment, x is about 15. In some embodiments, a current of at least x times C is a C rate of at least x times C, where C rate and current are interchangeable. In these embodiments, x is from about 1 C to about 15 C.

[0136] In some embodiments, the transition temperature is between about 60°C and about 125°C. In another embodiment, the transition temperature is about 60°C. In another embodiment, the transition temperature is about 65°C. In another embodiment, the transition temperature is about 70°C. In another embodiment, the transition temperature is about 72°C. In another embodiment, the transition temperature is about 75°C. In another embodiment, the transition temperature is about 80°C. In another embodiment, the transition temperature is about 85°C. In another embodiment, the transition temperature is about 90°C. In another embodiment, the transition temperature is about 95°C. In another embodiment, the transition temperature is about 100°C. In another embodiment, the transition temperature is about 105°C. In another embodiment, the transition temperature is about 110°C. In another embodiment, the transition temperature is about 115°C. In another embodiment, the transition temperature is about 120°C. In another embodiment, the transition temperature is about 125°C.

[0137] For example, 60°C may be the maximum temperature at which a lithium-ion cell should be expected to function reliably over an extended period of time. 125°C is the maximum temperature at which a lithium-ion battery can be expected to function under abusive operating conditions when a diethyl carbonate-based electrolyte is employed (e.g., its boiling point is about 126°C to about 128°C). In another example, 72°C is the maximum soaking temperature at which a lithium-ion battery must maintain voltage under UN38.3, IEC62133, and UL1642 standards. In some embodiments, the transition temperature may be about 85°C (e.g., 85°C for LiPF6) where the electrolyte salt begins to decompose and the battery may be irreversibly damaged. In some embodiments, the transition temperature may be about 90°C (e.g., 90°C for dimethyl carbonate, which lowers the boiling point of the linear alkyl carbonate solvent used in most electrolytes).

[0138] In some embodiments, the electrical resistance increases without completely decoupling both the electrode bus bar 308 and the electrode current collector 214 from the current limiter 206. In other embodiments, the electrode bus bar 208 is configured by a design that bends, distorts, or deforms above a transition temperature to at least partially decouple the electrode bus bar 208 from at least one of the electrode current collector 214 and the current limiter 206. In other embodiments, the electrode bus bar 208 comprises a bimetal. In other embodiments, the electrode bus bar 208 comprises a trimetal. In other embodiments, the electrode bus bar 208 comprises Nitinol.

[0139] In some embodiments, the electrode current collector 214 is configured with a design that bends, distorts, or deforms above a transition temperature to at least partially decouple the electrode current collector 214 from at least one of the electrode bus bar 208 and the current limiter 206. In other embodiments, the electrode current collector 214 comprises a bimetal. In other embodiments, the electrode current collector 214 comprises a trimetal. In other embodiments, the electrode collector 214 comprises nitinol.

[0140] In some embodiments, the electrode bus bar 208 and / or the counter electrode bus bar 210 are thermally coupled to an enclosure (not shown in FIG. 2 ) to facilitate heat transfer from the electrode assembly 200 to the enclosure. In some embodiments, the enclosure is hermetically sealed. In some embodiments, the enclosure is a pouch for the electrode assembly 200. For example, Joule heating of the current limiter 206 can thermally heat the electrode bus bar 208, which conducts heat from the electrode assembly 200 to the pouch (not shown in FIG. 2 ). Other embodiments of the electrode assembly 200 include a current limiter 206 disposed between the counter electrode bus bar 210 and the counter electrode current collector 218, which can operate in a similar manner as described for FIG. 2 .

[0141] The specific physical orientation and connections of the components of the electrode assembly 200 may vary in different embodiments. Specifically, the connections between the electrode current collector 214, the current limiter 206, and the electrode bus bar 208 of the electrode assembly 200, and their orientations, may vary. Some variations in orientation and connections are described below. All of the features discussed above with respect to FIG. 2 apply to the configurations discussed below, unless explicitly stated otherwise.

[0142] 4A and 4B, in some embodiments using the connection method shown in FIGS. 3A and 3B, an example current limiter 206 is comprised of a single layer 400 of conductive adhesive disposed on a surface 402 of the electrode bus bar 208 to which the electrode current collector 214 is welded. The electrode current collector 214 includes slots 404 (FIG. 4B) and portions 406, similar to the slots 300 and portions 302 of the counter electrode current collector 218 shown in FIGS. 3A and 3B, which are similarly used to connect the electrode current collector 214 to the electrode bus bar 108. Each individual current limiter 206 is a portion 408 of the single layer 400 located between the current collector portions 406 that are bent over and welded to the electrode bus bar 208. In other embodiments, the conductive adhesive is applied to the electrode bus bar 208 in individual portions, one for each electrode current collector 214 that is connected to the electrode bus bar 208. For example, conductive adhesive may be applied to the electrode bus bar 208 around the location of the portion 406 where the electrode current collector will be positioned when the portion 406 is bent over the electrode bus bar. Each application of conductive adhesive, and therefore each current limiter 206, is physically separated from each other application of conductive adhesive. In other embodiments, the conductive adhesive of the current limiters 206 is applied to each electrode current collector 214 such that the conductive adhesive is positioned around the location of the portion 406 in FIG. 4B , physically separating each current limiter 206 from the other current limiters 206. In other embodiments, the bus bar is connected to the current collector by any other suitable connection arrangement (e.g., the bus bar is on top of the end of the current collector without the use of a slot), and conductive adhesive is positioned between the current collector and the bus bar(s). As discussed above with respect to FIG. 2, the current limiter 206 formed by the portion 406 of the single layer 400 includes interfaces 220, 222 between the current limiter 206 and the electrode current collector 214 and electrode bus bar 208, respectively.

[0143] 4B , interfaces 220, 222 are formed between portion 406 of electrode current collector 214, electrode bus bar 208, and portion 408 of single layer 400. Specifically, interface 220 is formed between portion 406 of electrode current collector 214 and portion 408 of single layer 400, and interface 222 is formed between electrode bus bar 208 and portion 408 of single layer 400. Portion 408 of single layer 400 adheres to portion 406 of electrode current collector 214 and electrode bus bar 208 at interfaces 220, 222, respectively. For example, during normal operating currents and temperatures of portion 408 of single layer 400, interfaces 220, 220 form mechanical and electrical connections between portion 408 of single layer 400, portion 406 of electrode current collector 214, and electrode bus bar 208, respectively.

[0144] In one embodiment, each member of the electrode assembly 200's unit cell assembly has an ionic resistance, and the surface 228 of the electrode bus bar and the surface 230 of the electrode active material layer 212 are separated by a separation distance. The separation distance between the surfaces 228 and 230 decreases upon the formation of an electrical short within the member of the unit cell assembly, such that the electrical short has a resistance less than the ionic resistance of the member of the unit cell assembly in which the electrical short is formed. In another embodiment, the surface 224 of the electrode bus bar and the surface 226 of the portion 406 of the electrode current collector 214 are separated by a separation distance. The separation distance between the surfaces 224 and 226 increases upon the formation of an electrical short within the member of the unit cell assembly, such that the electrical short has a resistance less than the ionic resistance of the member of the unit cell assembly in which the electrical short is formed.

[0145] In another embodiment, each of the collection of unit cells of electrode assembly 200 has a capacitance (C), and surface 228 of electrode bus bar and surface 230 of electrode active material layer 212 are separated by a separation distance. The separation distance between surfaces 228 and 230 decreases upon passage of a current through portion 408 of single layer 400 at a current of at least x times C. In another embodiment, surface 224 of electrode bus bar and surface 226 of portion 406 of electrode current collector 214 are separated by a separation distance. The separation distance between surfaces 224 and 226 increases upon passage of a current through portion 408 of single layer 400 at a current of at least x times C. In some embodiments, x is between about 1 and about 15.

[0146] 18 shows an example of another embodiment in which the electrode current collector 214 does not include the slot 300. The current limiter 206 is composed of a single layer 1801 of conductive adhesive disposed on the surface 228 of the electrode bus bar 208 to which the electrode current collector 214 will be attached. A portion 1802 of the electrode current collector 214 is bent at approximately a 90-degree angle, and the electrode bus bar 208 is positioned over the portion 1802. It should be understood that the portion 1802 need not be bent at exactly 90 degrees, but may be generally perpendicular to the remainder of the current collector. The electrode bus bar 208 is then attached to the portion 1802 of the electrode current collector 214, such as by gluing, welding, soldering, or using any other suitable technique for joining the electrode current collector 214 to the electrode bus bar 208. In the example embodiment, the electrode bus bar 208 is attached to the portion 1802 by hot pressing the electrode bus bar to soften the conductive adhesive and applying pressure to the bus bar to bond the electrode bus bar 208 to the portion 1802 using the conductive adhesive. Although shown abutting against the conductive adhesive, it should be understood that the current collector portion 1802 may extend into the conductive adhesive. Each individual current limiter 206 is a portion 1804 of a single layer 1801 that is bent over and positioned between the current collector portions 1802 that are attached to the electrode bus bar 208.

[0147] 18 , interfaces 220 and 222 are formed between portion 1802 of electrode current collector 214, electrode bus bar 208, and portion 1804 of single layer 1801. Specifically, interface 220 is formed between portion 1802 of electrode current collector 214 and portion 1804 of single layer 1801, and interface 222 is formed between electrode bus bar 208 and portion 1804 of single layer 1801. Portion 1804 of single layer 1801 adheres to portion 1802 of electrode current collector 214 and electrode bus bar 208 at interfaces 220 and 222, respectively. For example, during normal operating currents and temperatures of portion 1804 of single layer 1801, interfaces 220 and 222 form mechanical and electrical connections between portion 1802 of electrode current collector 214 and electrode bus bar 208, respectively.

[0148] In one embodiment, each of the unit cell clusters of the electrode assembly 200 has an ionic resistance, and the surface 228 of the electrode bus bar and the surface 230 of the electrode active material layer 212 are separated by a separation distance. The separation distance between the surfaces 228 and 230 increases upon the formation of an electrical short within the member of the unit cell cluster, the electrical short having a resistance less than the ionic resistance of the member of the unit cell cluster in which the electrical short is formed. In another embodiment, the surface 228 of the electrode bus bar 208 and the surface 232 of the portion 1802 of the electrode current collector 214 are separated by a separation distance. The separation distance between the surfaces 228 and 232 increases upon the formation of an electrical short within the member of the unit cell cluster, the electrical short having a resistance less than the ionic resistance of the member of the unit cell cluster in which the electrical short is formed.

[0149] In another embodiment, each of the unit cell clusters of the electrode assembly 200 has a capacitance (C), and the surface 228 of the electrode bus bar 208 and the surface 230 of the electrode active material layer 212 are separated by a separation distance. The separation distance between the surfaces 228 and 230 increases upon passage of a current through the portion 1804 of the single layer 1801 at a current of at least x times C. In another embodiment, the surface 228 of the electrode bus bar 208 and the surface 232 of the portion 1802 of the electrode current collector 214 are separated by a separation distance. The separation distance between the surfaces 228 and 232 increases upon passage of a current through the portion 1804 of the single layer 1801 at a current of at least x times C. FIG. 22 shows an example of another embodiment in which the electrode current collector 214 does not include the slot 300. The current limiter 206 is comprised of a single layer 1801 of conductive adhesive disposed on the surface 228 of the electrode bus bar 208 to which the electrode current collector 214 is attached. In this embodiment, the electrode current collector 214 extends substantially straight from the electrode active material 212 such that the end 2202 of the electrode current collector 214 is positioned adjacent the surface 228 of the electrode bus bar 208. The electrode bus bar 208 is then mechanically attached to the end 2202 of the electrode current collector 214 by a single layer of conductive adhesive and / or by using glue, welding, soldering, or any other suitable technique for joining the electrode current collector 214 to the electrode bus bar 208. In the example embodiment, the electrode bus bar 208 is attached to the end 2202 by hot pressing the electrode bus bar 208 to soften the conductive adhesive and applying pressure to the electrode bus bar 208 to bond the electrode bus bar 208 to the end 2202 of the electrode current collector 214 using the conductive adhesive. While shown extending into the conductive adhesive, it should be understood that the end 2202 of the electrode current collector 214 may abut the conductive adhesive. Each individual current limiter 206 is a portion 1804 of a single layer 1801 located between an end 2202 of an electrode current collector 214 and a surface 228 of an electrode bus bar 208. Current limiters 206 formed from portions 1804 of a single layer 1801 may operate in a similar manner as previously described.

[0150] 19 and 21, conductive adhesive is applied to the electrode bus bar 208 in individual sections 1900, one for each electrode current collector 214 connected to the electrode bus bar 208. For example, the conductive adhesive is applied to the electrode bus bar 208 around the location of the section of the electrode bus bar where the individual section 1900 is positioned (e.g., 1802 in FIG. 19). Each application of conductive adhesive, and therefore each current limiter 206, is physically separated from each other application of conductive adhesive. In another embodiment, the conductive adhesive of the current limiters 206 is applied to each electrode current collector 214 such that the conductive adhesive is positioned around the location of the section (e.g., 1802 in FIG. 21) and each current limiter 206 is physically separated from the other current limiters 206.

[0151] 19 , interfaces 220, 222 are formed between portion 1802 of electrode current collector 214, electrode bus bar 208, and conductive adhesive portion 1900. Specifically, interface 220 is formed between portion 1802 of electrode current collector 214 and conductive adhesive portion 1900, and interface 222 is formed between electrode bus bar 208 and conductive adhesive portion 1900. Conductive adhesive portion 1900 adheres to portion 1802 of electrode current collector 214 and electrode bus bar 208 at interfaces 220, 222, respectively. For example, during normal operating currents and temperatures of conductive adhesive portion 1900, interfaces 220, 220 form mechanical and electrical connections between conductive adhesive portion 1900, portion 1802 of electrode current collector 214, and electrode bus bar 208, respectively.

[0152] In another embodiment, each of the collection of unit cells of the electrode assembly 200 has a capacitance (C), and the surface 228 of the electrode bus bar 208 and the surface 230 of the electrode active material layer 212 are separated by a separation distance. The separation distance between the surfaces 228 and 230 increases upon passage of a current through the conductive adhesive portion 1900 at a current of at least x times C. In another embodiment, the surface 228 of the electrode bus bar 208 and the surface 232 of the portion 1802 of the electrode current collector 214 are separated by a separation distance. The separation distance between the surfaces 228 and 232 increases upon passage of a current through the conductive adhesive portion 1900 at a current of at least x times C.

[0153] In other embodiments, for example, as shown in FIG. 21 , conductive adhesive is applied to the electrode bus bar 208 in individual portions 1900, one for each electrode current collector 214 connected to the electrode bus bar 208. For example, the conductive adhesive is applied to the electrode bus bar 208 around the location of the end 2202 where the electrode current collector 214 would be positioned when the end 2202 is positioned adjacent to the electrode bus bar 208. Each application of conductive adhesive, and therefore each current limiter 206, is physically separated from each other application of conductive adhesive. In other embodiments, the conductive adhesive of the current limiters 206 is applied to each electrode current collector 214 such that the conductive adhesive is positioned around the location of the end 2202, physically separating each current limiter 206 from the other current limiters 206. Current limiters 206 formed from the portions 1900 of conductive adhesive may operate in a similar manner as described above.

[0154] In still other embodiments, resistors other than conductive adhesives are used in the current limiter 206. For example, a conductive film having a desired resistance may be applied to the electrode bus bar 208 in a single strip, in individual sections to the electrode bus bar, or in individual sections to each electrode current collector 214 in a manner similar to conductive adhesive. Alternatively, a non-adhesive conductive polymer may be applied in place of conductive adhesive. Furthermore, in some embodiments, individual resistors may be electrically connected between the electrode current collector 214 and the electrode bus bar 208. The individual resistors may be physically located between the electrode current collector 214 and the electrode bus bar 208, or may be physically outside the interface between the electrode current collector 214 and the electrode bus bar 208 but electrically located between the electrode current collector 214 and the electrode bus bar 208. The individual resistors may be any suitable resistor, including wirewound resistors, thick film resistors, thin film resistors, carbon film resistors, carbon pile resistors, metal film resistors, foil resistors, etc.

[0155] In some embodiments, one or more interfacial layers are included between the current limiter 206 and the electrode bus bar 208 or between the current limiter 206 and the electrode current collector 214. Generally, the resistance between the electrode bus bar 208 and each electrode current collector 214 is defined by the resistance of the interface between the current limiter 206 and the electrode bus bar 208, in addition to the resistance of the current limiter 206, plus the resistance of the interface between the current limiter 206 and the electrode current collector 214. Generally, the interfacial resistance may be generated by imperfect (e.g., "real" rather than "ideal") electrical connections between the current limiter 206, the electrode bus bar 208, and the electrode current collector 214. Without being limited to any particular theory, the imperfect electrical connection may be caused by, for example, microscopic structural variations in the surfaces of the electrode bus bar 208 and / or the electrode current collector 214, the distribution and structure of conductive particles within the current limiter 206, etc.

[0156] The interface layer is provided to improve the electrical connection between these components to reduce the series resistance of the electrical connection between the current limiter 206, the electrode bus bar 208, and the electrode current collector 214. Referring now to Figures 14-16, an embodiment similar to that shown in Figure 4B is shown. Like reference numbers in Figures 14-16 refer to like components in Figure 4B. In Figure 14, an interface layer 1400 is applied to the electrode bus bar 208. In this embodiment, the current limiter 206 is formed from portion 408 of a single layer 400 and operates substantially similarly to that described above with respect to Figures 4A and 4B.

[0157] 14 , interface 220 is formed between portion 406 of electrode current collector 214 and portion 408 of monolayer 400, interface 1402 is formed between electrode bus bar 208 and interface layer 1400, and interface 1404 is formed between interface layer 1400 and portion 408 of monolayer 400. During normal operation, adhesion is formed at interfaces 220, 1402, and 1404. For example, during normal operating currents and temperatures of portion 408 of monolayer 400, interfaces 220, 1402, and 1404 form mechanical and electrical connections between portion 406 of electrode current collector 214 and electrode bus bar 208.

[0158] 15, an interfacial layer 1500 is applied to the electrode current collectors 214. The interfacial layer 1500 may be applied to each electrode current collector 214 or to less than all of the electrode current collectors 214.

[0159] 15 , interface 222 is formed between portion 408 of monolayer 400 and electrode bus bar 208, interface 1406 is formed between portion 406 of electrode current collector 214 and interface layer 1500, and interface 1408 is formed between interface layer 1500 and portion 408 of monolayer 400. During normal operation, adhesion is formed at interfaces 222, 1406, and 1408. For example, during normal operating currents and temperatures of portion 408 of monolayer 400, interfaces 222, 1406, and 1408 form mechanical and electrical connections between portion 406 of electrode current collector 214 and electrode bus bar 208.

[0160] In FIG. 16, interface layer 1400 is applied to electrode busbar 208 and interface layer 1500 is applied to electrode current collector 214 .

[0161] 16 , interface 1402 is formed between electrode bus bar 208 and interface layer 1400, interface 1404 is formed between interface layer 1400 and portion 408 of monolayer 400, interface 1406 is formed between portion 406 of electrode current collector 214 and interface layer 1500, and interface 1408 is formed between interface layer 1500 and portion 408 of monolayer 400. During normal operation, adhesion is formed at interfaces 1402, 1404, 1406, and 1408. For example, during normal operating currents and temperatures of portion 408 of monolayer 400, interfaces 1402, 1404, 1406, and 1408 form mechanical and electrical connections between portion 406 of electrode current collector 214 and electrode bus bar 208.

[0162] In some embodiments, the interface layers 1400 and 1500 are carbon-based coatings. For example, the interface layers 1400 and / or 1500 may be coatings produced by slurry coating carbon nanotubes onto the electrode bus bars 208 and / or electrode current collectors 214. In other embodiments, the interface layers are graphite coatings or any other suitable electrically conductive coatings. In some embodiments, the interface layers 1400 and / or 1500 are applied using a hot anvil technique in which heat is applied to the electrode bus bars 208 and / or electrode current collectors 214 to coat the electrode bus bars 208 and / or electrode current collectors 214 with the selected material to form the interface layers 1400 and / or 1500.

[0163] The conductive adhesive used in the current limiter 206 in the example embodiment is an adhesive polymer, copolymer, or blend with a conductive material suspended therein. In the example embodiment, the conductive adhesive is a thermoplastic material. In other embodiments, the conductive adhesive is a thermosetting material. The adhesive polymer is substantially non-conductive (e.g., insulating) prior to the suspension of the conductive material therein. Generally, a desirable polymer is any that (a) is stable in the environment of a lithium-ion battery cell (i.e., does not dissolve in the electrolyte, react with the electrolyte components or any other battery components, or undergo redox chemistry or reactions that degrade the material during cell operation), and (b) has a melting point above the typical operating temperature of a lithium-ion battery. Because adhesion is an important characteristic of a conductive adhesive, a polymer that exhibits adhesive properties is desirable as at least one component of the conductive adhesive. Flexibility of the polymer is another desirable attribute. Therefore, a material or blend of materials that has some degree of elasticity, particularly a glass transition temperature (Tg) above 0° C., is preferred, but not required. In some embodiments, the conductive adhesive is a polymer blend having at least one component with high elasticity (measured by standard methods such as modulus and / or elongation to break). In some embodiments, the adhesive polymer is a flowable adhesive polymer. In such embodiments, the conductive adhesive must have flow properties that allow melt processing, including the incorporation of conductive aids and other additives, if desired, and film / sheet preparation by standard methods such as cast film, blown film, and calendering. For example, the melt flow index (I2, 190°C, ASTM D1238) of the polymer blend used in the conductive adhesive should be in the range of 0.1 to 1000 grams (g) / 10 minutes, preferably 0.1 to 100 g / 10 minutes, and most preferably 0.5 to 20 g / 10 minutes. The melting point of the polymer used in the conductive adhesive must allow melt processing and bonding to the cell via melt pressing or related techniques and exceed the typical operating temperature range of the cell. Polymers that melt at 40°C to 300°C may be used in the conductive adhesive.Polymers having a melting point in the range of 60°C to 200°C are preferred, with polymers having a melting point in the range of 70°C to 165°C being most preferred.

[0164] Examples of suitable adhesive polymers or copolymers for use in the conductive adhesive include EAA (ethylene-co-acrylic acid) and EMAA (ethylene-co-methacrylic acid), ionomers of EAA or EMAA, polyethylene and copolymers thereof (such as ethylene / 1-octene, ethylene / 1-hexene, ethylene / 1-butene, and ethylene / propylene copolymers), polypropylene and copolymers thereof, functionalized or derivatized polyethylene or polypropylene (such as maleic anhydride grafted materials), and the like.

[0165] The conductive material suspended in the polymer to form the conductive adhesive can be any powder, fiber, particle, etc. that imparts the desired conductivity to the conductive adhesive after compounding with the polymer blend. Because high loadings of additives can alter the properties of the polymer blend in undesirable ways, materials that impart the desired conductivity at lower loadings are most desirable. For example, high loadings can lead to a significant decrease in melt processability, affecting the ability to manufacture conductive polymer films or sheets using conventional equipment. In addition, conductive additives are often expensive materials, and lower loadings are desirable to maintain lower manufacturing costs.

[0166] The conductive material may be metal powder or fiber, conductive carbon black, metal-coated carbon fiber, and carbon nanotubes, or a blend thereof. In various embodiments, the conductive material may be carbon black, nickel particles, copper particles, gold particles, silver particles, tin particles, titanium particles, graphite particles, molybdenum particles, platinum particles, chromium particles, aluminum particles, or any other metal particles, including alloys. Preferred conductive materials for use in the conductive adhesive are metal-coated carbon fiber and conductive carbon black, or a blend thereof. Metal-coated carbon fiber may be coated with any other metal coating, including nickel, copper, gold, silver, tin, titanium, molybdenum, platinum chromium, aluminum, or an alloy. In the most preferred examples, the conductive materials include nickel-coated carbon fibers and "superconducting" carbon black (examples include, but are not limited to, Nouryon Ketjenblack EC 300-J and EC 600-JD materials, Orion Printex XE2B, Cabot Vulcan XCmax™ 22).

[0167] For embodiments in which the conductive material is a fiber (such as a nickel-coated carbon fiber), the conductive material generally has an elongated shape. In such embodiments, it is preferred that the fiber have a relatively large aspect ratio (length to diameter). In one embodiment, nickel-coated carbon fiber used as the conductive material in the conductive adhesive has an aspect ratio of about 850:1. Other useful aspect ratios for the conductive material are 10:1 to 10,000:1, preferably 50:1 to 5000:1, and most preferably 100:1 to 2000:1.

[0168] The loading of conductive material into the polymer to form the conductive adhesive can range from 1% to 50% conductive material (as a weight percent of the total mixture), preferably the loading of conductive material is 2% to 40%, and most preferably the loading is 3% to 30%.

[0169] The resistivity of the conductive adhesive is 5.0 x 10 -7 and 5.0 x 10 3 Ω-cm, preferably 5.0 x 10 -5 and 5.0 x 10 1 Ω-cm to, most preferably, 5.0×10 -3 and 5.0 x 10 -1 The resistivity must be in the range of Ω-cm to Ω-cm. Polymer resistivity is measured by preparing a sheet or film of the polymer blend with conductive additive(s) and then thinning the sheet or film onto a copper test structure consisting of four rectangular bars bonded adjacent to each other in an array with a defined spacing. Thinning can be achieved using methods such as hot pressing or a heated calendar. Once thinning is complete, resistivity measurements are achieved using a typical four-point probe method, where a source probe applies current through the sheet of film by contacting the two outermost bars, and a sense probe measures the potential between the innermost bars, which allows for the determination of bulk resistivity when the geometry of the four-point test structure array and the thickness of the sheet or film are defined.

[0170] In an example embodiment, the conductive material is carbon black. The conductive adhesive is formed by mixing carbon black into the adhesive polymer until the adhesive polymer has a volume resistivity of approximately 0.01 to 1.0 Ω-cm. The resistivity can be adjusted by adjusting the amount of carbon black added to the adhesive polymer. Adding more carbon black decreases the resistivity (i.e., makes it more conductive), while adding less carbon black increases the resistivity (i.e., makes it less conductive). In an example embodiment, carbon black is added to the adhesive polymer in an amount of 5% to 30% by weight to achieve the desired resistivity. The conductive adhesive thus prepared is applied to the electrode bus bar 208 at a thickness of 20 microns to 200 microns. By adjusting the resistivity of the adhesive polymer and the application thickness, the desired resistance for the current limiter 206 can be achieved.

[0171] FIG. 5 is a simplified diagram of another example electrode assembly 500 for cycling between charge and discharge states in a battery. The electrode assembly 500 is similar to the electrode assembly 200, and the same reference numerals are used to identify common components. The features and operation are the same as the electrode assembly 200, except as explicitly stated herein. For clarity of illustration, the separator structure 205 is not shown in FIG. 5 but is included in this example electrode assembly 500. Unlike the electrode assembly 200, the electrode assembly 500 includes a collection of additional current limiters 502. The additional current limiters 502 are each electrically connected between a different one of the counter electrode current collectors 218 and the counter electrode busbar 210. In some embodiments, the additional current limiters 502 are the same as the current limiter 206 discussed above, and are connected in the same manner as the current limiter 206. However, in some embodiments, the additional current limiters 502 have a different composition and / or are different from the current limiter 206. For example, a conductive film may be used as the resistance of the additional current limiter 502, while a conductive adhesive is used in the current limiter 206. Alternatively, one type of conductive adhesive may be used in the current limiter 206, and a different type of conductive adhesive may be used in the additional current limiter 502. This may be particularly useful when the counter electrode bus bar 210 and the electrode bus bar 208 are made of different materials that may adhere differently to different conductive adhesives. As another example, the additional current limiter 502 may use a different conductive material suspended in a conductive adhesive than the current limiter 206. Furthermore, in some embodiments, the additional current limiter 502 has a different resistance than the current limiter 206. In certain embodiments, the additional current limiter 502 has a resistance less than that of the current limiter 206, including having a resistance of less than 0.25 Ω when the resistance of the current limiter 206 is sufficient to limit the current below a threshold that leads to catastrophic failure.

[0172] 5 , interfaces 504 and 506 are formed between the counter electrode current collector 218, the counter electrode bus bar 210, and the additional current limiter 502. Specifically, interface 504 is formed between the counter electrode current collector 218 and the additional current limiter 502, and interface 506 is formed between the counter electrode bus bar 210 and the additional current limiter 502. The additional current limiter 502 is bonded to the counter electrode current collector 218 and the counter electrode bus bar 210 at interfaces 504 and 506, respectively. For example, during normal operating currents and temperatures of the additional current limiter 502, interfaces 504 and 506 form mechanical and electrical connections between the additional current limiter 502, the counter electrode current collector 218, and the counter electrode bus bar 210, respectively.

[0173] 6 is a simplified diagram of another example electrode assembly 600 for cycling between charge and discharge states in a battery. The electrode assembly 600 is similar to the electrode assembly 200, and the same reference numerals are used to identify common components. The features and operation are the same as the electrode assembly 200, except as explicitly stated herein. For clarity of illustration, some details of the electrode structure 202 and counter electrode structure 204 are omitted, but all aspects of the electrode structure 202 and counter electrode structure 204 discussed above remain the same in the electrode assembly 600. Unlike the electrode assembly 200, the electrode assembly 600 includes a collection of additional electrode structures 602 that are directly connected to the electrode bus bar 208. That is, the additional electrode structures 602 are connected to the electrode bus bar 208 without the current limiter 206.

[0174] FIG. 7 is a simplified diagram of another example electrode assembly 700 for cycling between charge and discharge states in a battery. Electrode assembly 700 is similar to electrode assembly 500, and the same reference numbers are used to identify common components. The features and operation are the same as electrode assembly 200, except as explicitly stated herein. For clarity of illustration, some details of electrode structure 202 and counter electrode structure 204 are omitted, but all aspects of electrode structure 202 and counter electrode structure 204 discussed above are the same in electrode assembly 700. Unlike electrode assembly 500, electrode assembly 500 includes a collection of additional electrode structures 602 and a collection of additional counter electrode structures 704, all directly connected to electrode bus bar 208. That is, the additional electrode structures 602 and additional counter electrode structures 704 are connected to electrode bus bar 208 without current limiter 206 or additional current limiter 502. Current limiter 206 and additional current limiter 502 operate in substantially the same manner as described above with respect to FIGS. 2 and 5 for electrode structure 202 and counter electrode structure 204.

[0175] FIG. 9 illustrates a stacked cell 900 created as part of the manufacture of a secondary battery. To form a secondary battery, an electrode assembly, such as electrode assembly 200, 500, 600, or 700, is first assembled. An electrode structure 202, a counter electrode structure 204, and (if applicable) an additional electrode structure 602 and / or an additional counter electrode structure 704 are assembled. The formed electrode structure 202, counter electrode structure 204, additional electrode structure 602, and additional counter electrode structure 704 are referred to as "electrode subunits" in the following paragraphs. A predetermined number of electrode subunits are stacked with a separator structure 205 in a stacking direction (e.g., the width direction in FIG. 2 ) to form a multi-unit electrode stack. Generally, at least 10 electrode structures 202 and at least 10 counter electrode structures 204 are included in the multi-unit electrode stack. In some embodiments, at least 20 electrode structures 202 and at least 20 counter electrode structures 204 are included in the multi-unit electrode stack. Other embodiments may include any suitable number of electrode structures 202 and at least 10 counter electrode structures 204 in the multi-unit electrode stack. The multi-unit electrode stack is then placed under a pressure constraint with a pressure plate applying pressure to the multi-unit electrode stack to bond all of the electrode subunits together.

[0176] In a multi-unit electrode stack, the electrode and counter electrode structures extend in a longitudinal direction perpendicular to the stacking direction (e.g., the length direction in FIG. 2 ). The end portions of the electrode current collectors (e.g., the portions of the electrode current collectors 214 extending above the remainder of the electrode structure 202 in FIGS. 4B , 14 , 15 , 16 , 18 , and 19 ) extend longitudinally past the electrode active material and separator structures. The end portions extending above the electroactive material and separator structures are bent so that they are approximately perpendicular to the longitudinal direction of the electrode structures and extend in or opposite the stacking direction, as shown in FIGS. 4B , 14 , 15 , 16 , 18 , and 19 . In non-slotted embodiments (e.g., FIGS. 18 and 19 ), the end portions are bent with the surfaces of the electrode bus bars in contact with the end portions of the electrode current collectors (i.e., the bent end portions) before the electrode bus bars are positioned extending in the stacking direction. In exemplary embodiments, a conductive adhesive layer (e.g., a conductive adhesive as discussed herein that functions as a current-limiting device) is located between the surface of the electrode bus bar and the end portion of the electrode current collector. In some embodiments, the conductive adhesive layer is disposed on the surface of the electrode bus bar that contacts the electrode current collector. In other embodiments, the conductive adhesive layer is disposed on the electrode current collector. In yet other embodiments, the conductive adhesive layer is a separate layer positioned between the electrode bus bar and the electrode current collector. Heat and pressure are applied to the electrode bus bar to bond the end portion of the electrode current collector to the bus bar through the conductive adhesive layer. The applied heat can be between 100°C and 300°C, preferably between 125°C and 250°C, and most preferably between 150°C and 225°C. The pressure can be between 10 psi and 1000 psi, preferably between 15 psi and 750 psi, and more preferably between 20 psi and 500 psi.

[0177] In embodiments using slots in the current collectors (e.g., FIGS. 4B and 14-16), the bus bars are inserted through the slots before the current collectors are bent. In such embodiments, the electrode bus bar 208 and counter bus bar 210 are positioned through slots 404, 300 (shown in FIGS. 3A-4B) in the respective current collectors 214, 218 with the current limiter 206 (and additional current limiter 502, if applicable) between the bus bar 208, 210 and the collector 214, 218. Once the bus bars 208, 210 are positioned through the slots 404, 300, the portions 406, 302 are bent toward their respective bus bars 208, 210. The electrode bus bar 208 is welded to the portion 406 of the electrode current collector 214, and the counter bus bar 210 is welded to the portion 302 of the counter current collector 218. The welding may be performed using a laser welder, friction welding, ultrasonic welding, or any suitable welding method for welding the bus bars 208, 210 to the current collectors 214, 218. After welding the bus bars to the multi-unit electrode stack, the stacked cell 900 is complete and may be placed in a battery-formed pouch, metal can, or other suitable container. In other embodiments, any other suitable method for connecting the electrode bus bars 208 and counter electrode bus bars 210 to the current collectors may be used, including methods that do not use slots, methods that attach the bus bars to the top of tabs on the current collectors, etc.

[0178] Figure 10 is a top view (i.e., viewed from the height direction H) of a portion of a stacked cell 900. The portion of the stacked cell 900 shown in Figure 9 includes one electrode structure 202 and two counter electrode structures 204. In this example, the electrode structure 202 is an anode electrode structure and the counter electrode structure 204 is a cathode electrode structure.

[0179] 11A and 11B, after the stacked cells 900 are formed, they proceed to a packaging station 1100, where they are coated with insulating packaging material 1101, such as a multi-layer aluminum polymer material, plastic, or the like, to form a battery package 1102. In one embodiment, the battery package 1102 is evacuated using a vacuum and filled with electrolyte material through an opening (not shown). The insulating packaging material may be sealed around the stacked cells 900 using heat sealing, laser welding, adhesives, or any suitable sealing method. After sealing, the battery-insulated packaging material forms a sealed enclosure. The ends of the bus bars 208 and 210 remain exposed and are not covered by the battery package 1102; the exposed ends serve as electrode and counter terminals external to the sealed battery enclosure. The exposed ends of the bus bars allow a user to connect the bus bars to a powered device or a battery charger. In other embodiments, separate external electrode and counter terminals are welded to the bus bars 208 and 210 and positioned outside the sealed battery package 1102. In some embodiments, the connections between such external electrode and counter terminals are located within the battery package 1102, and the ends of the bus bars 208, 210 do not extend outside the battery package 1102.

[0180] Referring now to FIG. 12, the thermal runaway current (I trA wet (i.e., the unit cell contains a liquid electrolyte) forced internal short circuit (FISC) assay can be performed to determine the current capacity (V) of the unit cell. The FISC assay is an iterative test. The test is performed on an electrode assembly containing n unit cells (where n is a positive integer). Each unit cell includes a single electrode structure 202 adjacent to a single counter electrode 204, with a separator structure 205 therebetween, and includes a current limiter 206. The first iteration is performed on an electrode assembly with n=1 (i.e., a single unit cell) electrically disconnected from any other electrode structures 202, 204. FIG. 12 shows a tested electrode assembly containing a single unit cell 1200. Note that FIG. 12 is not to scale. To perform the test, conductive particles 1202 are positioned in the region between the fully charged positive and negative electrodes of the unit cell (e.g., on the separator structure 205 between the electrode structure 202 and the counter electrode structure 204). In one example, the conductive particles 1202 are 2 mm x 0.2 mm x 0.1 mm L-shaped nickel particles. In other embodiments, the conductive particles 1202 may have any other suitable shape and / or may be made of any other suitable conductive material. The servo motor 1204 presses a 5 mm x 5 mm flat acrylic indenter 1206 onto the unit cell 1200 at a location where the embedded conductive particles are located, at a speed of 1.0 mm / s. This causes the conductive particles 1202 to electrically connect the electrode structure 202 and the counter electrode structure 204 in a short circuit. The servo motor 1204 continues to displace the indenter 1206 until a voltage drop of more than 80% of the unit cell voltage occurs. If the unit cell 1200 undergoes a catastrophic failure (e.g., the unit cell 1200 catches fire or explodes), the test is stopped. If a single unit cell 1200 fails the test, the configuration of the failed unit cell is determined using this test to determine the thermal runaway current (I tr ) for this configuration of unit cell 1200, different tests, estimates, simulations, etc. can be performed to determine the thermal runaway current (I tr) must be determined. Furthermore, if a single unit cell 1200 fails the test, the configuration of the failing unit cell may not be a good candidate for use with the current limiter described herein, as the resistance required for the current limiter to adequately limit the current may be high enough to result in undesirable energy loss under normal charging and discharging.

[0181] If no unit cells 1200 have suffered a catastrophic failure, the configuration of unit cells 1200 passes the first iteration, n is incremented by 1, and a new assembly is assembled containing two unit cells (i.e., n=2), one of which is configured with conductive particles 1202 as discussed above for the first step. The FISC test is repeated for this new assembly with two unit cells. If the new assembly passes the test, the above steps in this paragraph are performed again. That is, a new assembly with n=n+1 unit cells is assembled with one of the unit cells including conductive particles, and the FISC test is performed again. The worst-case forced internal short-circuit resistance is given at each step by: R s,WCFISC (n)=R 20kHz(Vtoc,n) (9) In this example, an impedance of 20 kHz is used, but an impedance at any other suitable non-zero frequency may be used. This iteration is repeated until the electrode assembly fails the test. If one of the electrode assemblies fails the test, the test is stopped. The number of unit cells from the last successful iteration (i.e., the electrode assembly with the current value of n-1 unit cells) is used to calculate the thermal runaway current (I tr ) is used to determine the thermal runaway current (I tr ) is given by:

number

[0182] Although discussed above as starting with a single unit cell and n=1, the assay may begin with any suitable, non-zero number of unit cells. For example, if a particular unit cell configuration is expected (e.g., estimated, calculated, etc.) to fail a test at n=4, testing can begin at n=3 with an electrode assembly containing three unit cells.

[0183] R in equation (6) s The actual short-circuit resistance for use as a unit cell can be determined using a dry FISC assay. A dry FISC assay is similar to the FISC assay discussed above, but is performed on one or more unit cells. In a dry FISC assay, one or more unit cells without any electrolyte are subjected to FISC using the assembly and techniques described above with reference to FIG. 12 . That is, a unit cell (including a single electrode structure 202 adjacent to a single counter electrode 204 having a separator structure 205) has conductive particles 1202 positioned in the region between the positive and negative electrodes of the unit cell (e.g., on the separator structure 205 between the electrode structure 202 and the counter electrode structure 204), and an indenter 1206 compresses the unit cell, causing the conductive particles 1202 to electrically connect the electrode structure 202 and the counter electrode structure 204 in a short circuit. The actual short-circuit resistance of the shorted unit cell can then be measured and used in equation (6).

[0184] FIG. 13 is a simplified diagram of a portion of another electrode assembly 1300 for cycling between charge and discharge states in a battery. The electrode assembly 1300 includes similar components to the electrode assemblies described above, and the components are the same unless otherwise specified. For clarity, the counter electrode structure assembly, separator structure assembly, and counter electrode bus bar are omitted from the figure. The current limiter 206 assembly in the electrode assembly 1300 has fewer components than the electrode structure 202 assembly. The electrode structure assembly is divided into groups 1302 of electrode structures 202. Each group 1302 of electrode structures 202 includes two electrode structures 202 of FIG. 13. In other embodiments, the group 1302 can include any number of electrode structures 202, so long as the group includes more than one electrode structure 202. Each electrode structure 202 in a group 1302 is electrically connected in parallel to the other electrode structures 202 in that group 1302. The parallel connections of the electrode structures 202 in a group 1302 are connected to the electrode bus bar 208 by a single current limiter 206. That is, all of the electrode structures in a group 1302 share a single current limiter 206. Other embodiments may additionally or alternatively include similar grouped arrangements of counter electrode structures 204 that share a single current limiter 206. Furthermore, in some embodiments, some of the electrode structures 202 and / or some of the counter electrode structures 204 in an electrode assembly may be grouped as described above, while other electrode structures 202 and / or counter electrode structures 204 in the assembly are not grouped and each have their own current limiter 206.

[0185] The resistance of the current limiter 206 in the electrode assembly 1300 is determined by variation of inequality (6) discussed above. Specifically, the resistance of the shared current limiter 206 in the electrode assembly 1300 is determined to satisfy:

number

[0186] In some embodiments, the resistance of the current limiter 206 is defined by the relationship between the resistance of the current limiter and the cell resistance of the unit cells. Specifically, within a normal operating temperature range of minus 30 degrees Celsius (°C) to 80°C, each unit cell has a cell resistance R1. Each current limiter has a resistance R2 such that: R2 / R1>0.01 (12) This is when the electrode assembly is within its normal operating temperature range. The exact value of the ratio R2 / R1 can vary depending on the capacity and / or voltage of the battery. In example embodiments, R2 / R1 is approximately equal to 0.5, 0.95, or 0.0275. In some embodiments, R2 / R1 can be greater than 0.1, greater than 0.5, greater than 0.95, or greater than 0.1.

[0187] FIG. 20 is an example of another stacked cell 2000 created as part of the manufacture of a secondary battery. To form a secondary battery, an electrode assembly, such as electrode assembly 200, 500, 600, or 700, is first assembled. An electrode structure 202, a counter electrode structure 204, and (if applicable) an additional electrode structure 602 and / or an additional counter electrode structure 704 are assembled. The formed electrode structure 202, counter electrode structure 204, additional electrode structure 602, and additional counter electrode structure 704 are referred to as "electrode subunits" in the following paragraphs. A predetermined number of electrode subunits are stacked with a separator structure 205 in a stacking direction (e.g., the width direction in FIG. 2 ) to form a multi-unit electrode stack. Generally, at least 10 electrode structures 202 and at least 10 counter electrode structures 204 are included in the multi-unit electrode stack. In some embodiments, at least 20 electrode structures 202 and at least 20 counter electrode structures 204 are included in the multi-unit electrode stack. Other embodiments may include any suitable number of electrode structures 202 and at least 10 counter electrode structures 204 in the multi-unit electrode stack. The multi-unit electrode stack is then placed under a pressure constraint with a pressure plate applying pressure to the multi-unit electrode stack to bond all of the electrode subunits together.

[0188] In a multi-unit electrode stack, the electrode and counter electrode structures extend in a longitudinal direction perpendicular to the stacking direction (e.g., the length direction in FIG. 2 ). The end portions of the electrode current collectors (e.g., the portions of the electrode current collectors 214 extending above the remainder of the electrode structure 202 in FIGS. 18 and 19 ) extend longitudinally past the electrode active material and separator structures. In some embodiments, the end portions extending above the electroactive material and separator structures are bent so that they are approximately perpendicular to the longitudinal direction of the electrode structures and extend in or opposite the stacking direction, as shown in FIGS. 18 and 19 . In some non-slotted embodiments (e.g., FIGS. 18 and 19 ), the end portions are bent with a surface of the electrode bus bar in contact with the end portion of the electrode current collector (i.e., the bent end portion) before the electrode bus bar is positioned extending in the stacking direction. In still other embodiments, the upwardly extending end portions of the electroactive material and separator structure are not bent at all, as shown in FIGS. 21 and 22. In exemplary embodiments, a conductive adhesive layer (e.g., a conductive adhesive as discussed herein that functions as a current-limiting device) is located between the surface of the electrode bus bar and the end portion of the electrode current collector. In some embodiments, the conductive adhesive layer is disposed on the surface of the electrode bus bar that contacts the electrode current collector. In other embodiments, the conductive adhesive layer is disposed on the electrode current collector. In still other embodiments, the conductive adhesive layer is a separate layer positioned between the electrode bus bar and the electrode current collector. Heat and pressure are applied to the electrode bus bar to bond the end portion of the electrode current collector to the bus bar through the conductive adhesive layer. The applied heat can be between 100°C and 300°C, preferably between 125°C and 250°C, and most preferably between 150°C and 225°C. The pressure can be between 10 psi and 1000 psi, preferably between 15 psi and 750 psi, and more preferably between 20 psi and 500 psi.

[0189] 2 , in some embodiments, the bus bar 208 and / or counter electrode bus bar 210 are thermally coupled to a pouch 2002 that is at least partially thermally conductive with respect to the electrode assembly 200, 500, 600, or 700 to facilitate heat transfer from the bus bar 208 and / or counter electrode bus bar 210 to the pouch 2002. For example, Joule heating of the current limiter 206 may thermally heat the electrode bus bar 208 and / or Joule heating of the additional current limiter 502 may heat the counter electrode bus bar 210, thereby conducting heat from the electrode assembly 200, 500, 600, or 700 to the pouch 2002. In this embodiment, a thermally conductive material 2004 is applied to the electrode bus bar 208 and / or counter electrode bus bar 210 and contacts the electrode bus bar 208 and / or counter electrode bus bar 210 and the pouch 2002. In some embodiments, the thermally conductive material 2004 is an electrically insulating material to avoid electrically coupling the electrode bus bar 210 to the pouch 2002. In some embodiments, the pouch is made from an electrically insulating material. The thermally conductive material 2004 allows heat generated by the current limiter 206 and / or the additional current limiter 502 and applied to the electrode bus bar 208 and / or the counter electrode bus bar 210 to be transferred through the thermally conductive material 2004 to the pouch 2002, thereby removing heat from the stacked cell 2000 and reducing the possibility of thermal runaway of the stacked cell 2000 during abnormal operation of the stacked cell 2000.

[0190] For example, one or more of the current limiters 206 (see FIG. 2 ) may be subject to excessive Joule heating due to current flowing through and heating the current limiter 206 in response to an electrical short between the electrode active material 212 and the counter electrode active material 216. During these types of abnormal events, the heat generated by the current limiter 206 also heats the electrode bus bar 208, which transfers the heat to the pouch 2002 via the thermally conductive material 2004. This heat transfer removes heat from the stacked cell 2000, reducing the risk of fire and / or thermal runaway for the stacked cell 2000.

[0191] In another example, one or more of the additional current limiters 502 (see FIG. 5 ) may be subject to excessive Joule heating due to current flowing through and heating the additional current limiter 502 in response to an electrical short between the electrode active material 212 and the counter electrode active material 216. During these types of abnormal events, the heat generated by the additional current limiter 502 also heats the counter electrode bus bar 210, which transfers the heat to the pouch 2002 via the thermally conductive material 2004. This heat transfer removes heat from the stacked cell 2000, reducing the risk of fire and / or thermal runaway for the stacked cell 2000.

[0192] In some embodiments, the thermally conductive material 2004 comprises an epoxy, glue, or other type of material that secures the electrode bus bar 208 and / or counter electrode bus bar 210 to the pouch 2002 .

[0193] The following embodiments are provided to illustrate aspects of the present disclosure, but these embodiments are not intended to be limiting, and other aspects and / or embodiments may be provided.

[0194] Embodiment 1. An electrode assembly for cycling between a charged state and a discharged state, the electrode assembly being a collection of unit cells stacked on top of each other in a stacking direction, each member of the collection of unit cells including an electrode structure, a separator structure, and a counter electrode structure, the electrode structure comprising an electrode current collector and an electrode active material layer, the electrode structure extending in a longitudinal direction perpendicular to the stacking direction, an end portion of the electrode current collector extending in the longitudinal direction past an outer surface of the electrode active material layer and the separator structure, the counter electrode structure comprising a counter electrode current collector and a counter electrode active material layer, the counter electrode structure extending in the longitudinal direction perpendicular to the stacking direction; an adhesive layer comprising a resistive polymer material; and an electrode bus bar, the electrode bus bar extending in the stacking direction and having a first surface and a second surface opposite the first surface, the first surface positioned adjacent to the end portion of the electrode current collector, the first surface attached to the end portion of the electrode current collector through the adhesive layer.

[0195] Embodiment 2. An electrode assembly as described in embodiment 1, wherein (i) the adhesive layer is configured to adhere to the electrode bus bar and the electrode current collector below a transition temperature, and (ii) the adhesive layer is configured to at least partially melt above the transition temperature to increase the electrical resistance between the electrode bus bar and the electrode current collector.

[0196] Embodiment 3. An electrode assembly according to any one of the preceding embodiments, wherein (i) each member of the collection of unit cells has an ionic resistance, and (ii) the adhesive layer is configured to at least partially melt upon formation of an electrical short within a member of the collection of unit cells, the electrical short having an electrical resistance less than the ionic resistance of the member of the collection of unit cells in which the electrical short is formed.

[0197] Embodiment 4. The electrode assembly of any one of the preceding embodiments, wherein (i) each member of the collection of unit cells has a capacitance (C), and (ii) the adhesive layer is configured to at least partially melt upon passage of a current through the adhesive layer of a member of the collection of unit cells at a current of at least x times C of the member of the collection of unit cells.

[0198] Embodiment 5. An electrode assembly according to any one of the preceding embodiments, wherein (i) the resistive polymer material includes at least one phase change element configured to expand a volume of the adhesive layer at or above a transition temperature, (ii) the adhesive layer has a first volume below the transition temperature, and (iii) the adhesive layer is configured to expand from the first volume towards a second volume at or above the transition temperature to increase electrical resistance between the electrode bus bar and the electrode current collector.

[0199] Embodiment 6. An electrode assembly according to any one of the preceding embodiments, wherein (i) each member of the collection of unit cells has an ionic resistance, (i) the resistive polymer material includes at least one phase change element configured to expand the volume of the adhesive layer at or above a transition temperature, (ii) the adhesive layer has a first volume below the transition temperature, and (iii) the adhesive layer is configured to expand from the first volume towards a second volume at or above the transition temperature upon formation of an electrical short in a member of the collection of unit cells, the electrical short having an electrical resistance less than the ionic resistance of the member of the collection of unit cells in which the electrical short is formed.

[0200] Embodiment 7. The electrode assembly of any one of the preceding embodiments, wherein (i) each member of the collection of unit cells has a capacitance (C), (i) the resistive polymer material includes at least one phase change element configured to expand the volume of the adhesive layer at or above a transition temperature, (ii) the adhesive layer has a first volume below the transition temperature, and (iii) the adhesive layer is configured to expand from the first volume toward a second volume at or above the transition temperature upon passage of a current through the adhesive layer of a member of the collection of unit cells at a current of at least x times C of the member of the collection of unit cells.

[0201] Embodiment 8. The electrode assembly of any one of the preceding embodiments, wherein (i) each member of the collection of unit cells has an ionic resistance; (ii) the first surface of the electrode bus bar and the outer surface of the electrode active material layer are separated by a separation distance; and (iii) the separation distance between the first surface of the electrode bus bar and the outer surface of the electrode active material layer increases upon formation of an electrical short circuit within a member of the collection of unit cells, the electrical short circuit having an electrical resistance that is less than the ionic resistance of the member of the collection of unit cells in which the electrical short circuit is formed.

[0202] Embodiment 9. The electrode assembly of any one of the preceding embodiments, wherein (i) each member of the assembly of unit cells has a capacitance (C); (ii) the first surface of the electrode bus bar and the outer surface of the electrode active material layer are separated by a separation distance; and (iii) the separation distance between the first surface of the electrode bus bar and the outer surface of the electrode active material layer increases upon passage of a current through the adhesive layer of the member of the assembly of unit cells at a current of at least x times C of the member of the assembly of unit cells.

[0203] Embodiment 10. The electrode assembly of any one of the preceding embodiments, wherein (i) each member of the collection of unit cells has an ionic resistance; (ii) the first surface of the electrode bus bar and the outer surface of the electrode active material layer are separated by a separation distance; and (iii) the separation distance between the first surface of the electrode bus bar and the outer surface of the electrode active material layer decreases upon formation of an electrical short circuit within a member of the collection of unit cells, and the electrical short circuit has an electrical resistance that is less than the ionic resistance of the member of the collection of unit cells in which the electrical short circuit is formed.

[0204] Embodiment 11. An electrode assembly according to any one of the preceding embodiments, wherein (i) each member of the assembly of unit cells has a capacitance (C), (ii) the first surface of the electrode bus bar and the outer surface of the electrode active material layer are separated by a separation distance, and (iii) the separation distance between the first surface of the electrode bus bar and the outer surface of the electrode active material layer decreases upon passage of a current through the adhesive layer of the member of the assembly of unit cells at a current of at least x times C of the member of the assembly of unit cells.

[0205] Embodiment 12. An electrode assembly according to any one of the preceding embodiments, wherein (i) each member of the assembly of unit cells has an ionic resistance; (ii) the first surface of the electrode bus bar and the end portion of the electrode current collector are separated by a separation distance; and (iii) the separation distance between the first surface of the electrode bus bar and the end portion of the electrode current collector increases upon formation of an electrical short circuit within a member of the assembly of unit cells, the electrical short circuit having an electrical resistance less than the ionic resistance of the member of the assembly of unit cells in which the electrical short circuit is formed.

[0206] Embodiment 13. An electrode assembly according to any one of the preceding embodiments, wherein (i) each member of the assembly of unit cells has a capacitance (C), (ii) the first surface of the electrode bus bar and the end portion of the electrode current collector are separated by a separation distance, and (iii) the separation distance between the first surface of the electrode bus bar and the end portion of the electrode current collector increases upon passage of a current through the adhesive layer of the member of the assembly of unit cells at a current of at least x times C of the member of the assembly of unit cells.

[0207] Embodiment 14. An electrode assembly according to any one of the preceding embodiments, wherein (ii) the resistive polymer material has a melting point at a temperature defined by the design parameters of the adhesive layer, (iii) the adhesive layer has a first electrical resistance between the electrode bus bar and the electrode current collector below this temperature, and (iv) the electrical resistance of the adhesive layer increases from the first electrical resistance towards a second electrical resistance above this temperature as the adhesive layer partially melts.

[0208] Embodiment 15. An electrode assembly according to any one of the preceding embodiments, wherein (i) the electrode bus bar and the electrode current collector are configured to adhere to the adhesive layer below the transition temperature, and (ii) at least one of the electrode bus bar and the electrode current collector is configured to at least partially detach from the adhesive layer above the transition temperature.

[0209] Embodiment 16. An electrode assembly according to any one of the preceding embodiments, wherein (i) each member of the assembly of unit cells has an ionic resistance, and (ii) at least one of the electrode bus bar and the electrode current collector is configured to be at least partially detached from the adhesive layer upon the formation of an electrical short circuit within a member of the assembly of unit cells, the electrical short circuit having an electrical resistance less than the ionic resistance of the member of the assembly of unit cells in which the electrical short circuit is formed.

[0210] Embodiment 17. An electrode assembly according to any one of the preceding embodiments, wherein (i) each member of the assembly of unit cells has a capacitance (C), and (ii) at least one of the electrode busbar and the electrode current collector is configured to be at least partially decoupled from the adhesive layer of a member of the assembly of unit cells upon passage of a current through the adhesive layer of the member of the assembly of unit cells at a current of at least x times C of the member of the assembly of unit cells.

[0211] Embodiment 18. An electrode assembly described in any one of the preceding embodiments, wherein (i) the electrode bus bar and the electrode current collector are configured to adhere to the adhesive layer below the transition temperature, and (ii) at least one of the electrode bus bar and the electrode current collector is configured to be electrically disconnected from the adhesive layer above the transition temperature.

[0212] Embodiment 19. An electrode assembly according to any one of the preceding embodiments, wherein (i) each member of the assembly of unit cells has an ionic resistance, and (ii) at least one of the electrode bus bar and the electrode current collector is configured to be electrically disconnected from the adhesive layer upon the formation of an electrical short circuit within a member of the assembly of unit cells, the electrical short circuit having an electrical resistance less than the ionic resistance of the member of the assembly of unit cells in which the electrical short circuit is formed.

[0213] Embodiment 20. An electrode assembly according to any one of the preceding embodiments, wherein (i) each member of the assembly of unit cells has a capacitance (C), and (ii) at least one of the electrode bus bar and the electrode current collector is configured to be electrically decoupled from the adhesive layer of a member of the assembly of unit cells upon passage of a current through the adhesive layer of a member of the assembly of unit cells at a current of at least x times C of the member of the assembly of unit cells.

[0214] Embodiment 21. An electrode assembly according to any one of the preceding embodiments, wherein the end portions of each electrode current collector are bent in a direction perpendicular to the longitudinal direction of the electrode structure and extend in the stacking direction or opposite to the stacking direction.

[0215] Embodiment 22. An electrode assembly according to any one of the preceding embodiments, wherein the resistive polymer material comprises a thermoplastic material.

[0216] Embodiment 23. An electrode assembly according to any one of the preceding embodiments, wherein the resistive polymer material comprises an adhesive polymer and a conductive material suspended in the adhesive polymer.

[0217] Embodiment 24. An electrode assembly as described in embodiment 23, wherein the conductive material comprises nickel particles.

[0218] Embodiment 25. An electrode assembly as described in embodiment 23, wherein the conductive material comprises metal particles.

[0219] Embodiment 26. An electrode assembly as described in embodiment 23, wherein the conductive material comprises one or more of carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

[0220] Embodiment 27. An electrode assembly as described in embodiment 23, wherein the conductive material comprises metal-coated carbon fiber.

[0221] Embodiment 28. An electrode assembly as described in embodiment 27, wherein the metal-coated carbon fibers comprise nickel-coated carbon fibers.

[0222] Embodiment 29. An electrode assembly as described in embodiment 27, wherein the metal-coated carbon fiber has a length and a diameter, and the aspect ratio of the length to the diameter of the metal-coated carbon fiber is 10:1 or greater.

[0223] Embodiment 30. An electrode assembly as described in embodiment 29, wherein the metal coated carbon fiber has a length and a diameter, and the aspect ratio of the length to the diameter of the metal coated carbon fiber is from 10:1 to 10,000:1.

[0224] Embodiment 31. An electrode assembly as described in embodiment 30, wherein the aspect ratio of length to diameter is from 50:1 to 5,000:1.

[0225] Embodiment 32. An electrode assembly as described in embodiment 31, wherein the aspect ratio of length to diameter is from 100:1 to 2,000:1.

[0226] Embodiment 33. An electrode assembly as described in embodiment 32, wherein the aspect ratio of length to diameter is about 850:1.

[0227] Embodiment 34. An electrode assembly according to any one of the preceding embodiments, wherein the adhesive layer comprises a hot-melt adhesive polymer.

[0228] Embodiment 35. An electrode assembly according to any one of the preceding embodiments, wherein the resistive polymeric material has a melt flow index, determined according to ASTM D1238 at 190°C, of ​​0.1 to 1000 grams (g) / 10 minutes.

[0229] Embodiment 36. An electrode assembly according to embodiment 35, having a melt flow index of 0.1 to 100 g / 10 min.

[0230] Embodiment 37. An electrode assembly according to embodiment 36, having a melt flow index of 0.5 to 20 g / 10 min.

[0231] Embodiment 38. An electrode assembly according to any one of the preceding embodiments, wherein the resistive polymer material has a melting point of 40°C to 300°C.

[0232] Embodiment 39. An electrode assembly as described in embodiment 38, wherein the melting point of the resistive polymer material is 60°C to 200°C.

[0233] Embodiment 40. An electrode assembly as described in embodiment 39, wherein the resistive polymer material has a melting point of 70°C to 165°C.

[0234] Embodiment 41. An electrode assembly according to any one of the preceding embodiments, wherein an end portion of each counter electrode current collector extends past the counter electrode active material layer and separator structure in an opposite longitudinal direction to the end portion of the electrode current collector, wherein the end portion of each counter electrode current collector is bent so as to be approximately perpendicular to the longitudinal direction of the counter electrode structure and extend in the stacking direction or opposite the stacking direction, and wherein a counter electrode bus bar is positioned on a surface of the counter electrode bus bar that contacts the end portion of the counter electrode current collector and extends in the stacking direction, and wherein the counter electrode bus bar is attached to the end portion of the counter electrode current collector.

[0235] Embodiment 42. An electrode assembly as described in embodiment 41, wherein the surface of the counter electrode bus bar contacts the end portion of the counter electrode current collector and has a counter electrode adhesive layer comprising a resistive polymer material disposed thereon, and the counter electrode bus bar is attached to the end portion of the counter electrode current collector by the counter electrode adhesive layer.

[0236] Embodiment 43. An electrode assembly according to any one of the preceding embodiments, wherein the adhesive layer has a resistivity of 0.01 Ω·cm or greater.

[0237] Embodiment 44. An electrode assembly according to any one of the preceding embodiments, wherein the adhesive layer has a resistivity of 1.0 Ω·cm or less.

[0238] Embodiment 45. An electrode assembly according to any one of the preceding embodiments, wherein the adhesive layer comprises one of ethylene-co-acrylic acid, an ionomer of ethylene-co-acrylic acid, and a polymer of ethylene-co-acrylic acid.

[0239] Embodiment 46. An electrode assembly according to any one of the preceding embodiments, wherein the adhesive layer comprises one of ethylene-co-methacrylic acid, an ionomer of ethylene-co-methacrylic acid, and a polymer of ethylene-co-methacrylic acid.

[0240] Embodiment 47. An electrode assembly according to any one of the preceding embodiments, wherein the adhesive layer comprises a functionalized polyethylene.

[0241] Embodiment 48. An electrode assembly according to any one of the preceding embodiments, wherein the adhesive layer comprises functionalized polypropylene.

[0242] Embodiment 49. An electrode assembly described in any one of the preceding embodiments, wherein the resistive polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to at least partially melt above a transition temperature to increase the bulk resistivity of the adhesive layer.

[0243] Embodiment 50. An electrode assembly described in any one of the preceding embodiments, wherein the resistive polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to at least partially melt above a transition temperature to increase the bulk resistivity of the adhesive layer.

[0244] Embodiment 51. An electrode assembly described in any one of the preceding embodiments, wherein the resistive polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to at least partially melt at or above a transition temperature to increase the interfacial resistance between the adhesive layer and at least one of the electrode bus bar and the electrode current collector.

[0245] Embodiment 52. An electrode assembly described in any one of the preceding embodiments, wherein the resistive polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to at least partially melt above a transition temperature to reduce contact of the conductive material within the bulk of the adhesive layer and increase the volume resistivity of the adhesive layer.

[0246] Embodiment 53. An electrode assembly according to any one of the preceding embodiments, wherein the resistive polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to at least partially melt at or above a transition temperature and flow into and / or be drawn into the interface between the conductive materials.

[0247] Embodiment 54. An electrode assembly according to any one of the preceding embodiments, wherein the resistive polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to at least partially melt at or above a transition temperature and flow into and / or be drawn into an interface between the adhesive layer and at least one of the electrode busbar and the electrode current collector.

[0248] Embodiment 55. An electrode assembly according to any one of the preceding embodiments, wherein the resistive polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is an electrical insulator.

[0249] Embodiment 56. An electrode assembly according to any one of the preceding embodiments, wherein the adhesive layer is configured to at least partially carbonize at or above a transition temperature to increase the electrical resistance between the electrode bus bar and the electrode current collector.

[0250] Embodiment 57. An electrode assembly described in any one of the preceding embodiments, wherein the adhesive layer is configured to at least partially carbonize at or above a transition temperature to form an electrical insulating layer between the adhesive layer and at least one of the electrode bus bar and the electrode current collector.

[0251] Embodiment 58. An electrode assembly according to any one of the preceding embodiments, wherein the at least partial detachment from at least one of the electrode busbar and the electrode current collector is irreversible.

[0252] Embodiment 59. An electrode assembly according to any one of the preceding embodiments, wherein at least one phase change element comprises expandable graphite.

[0253] Embodiment 60. An electrode assembly according to any one of the preceding embodiments, wherein at least one phase change element comprises sodium carbonate.

[0254] Embodiment 61. An electrode assembly according to any one of the preceding embodiments, wherein at least one phase change element comprises calcium carbonate.

[0255] Embodiment 62. The electrode assembly of any one of the preceding embodiments, wherein x is from about 1 to about 15.

[0256] Embodiment 63. The electrode assembly of embodiment 62, wherein x is about 1.

[0257] Embodiment 64. An electrode assembly as described in embodiment 62, wherein x is about 2.

[0258] Embodiment 65. An electrode assembly as described in embodiment 62, wherein x is about 3.

[0259] Embodiment 66. An electrode assembly as described in embodiment 62, wherein x is about 4.

[0260] Embodiment 67. The electrode assembly of embodiment 62, wherein x is about 5.

[0261] Embodiment 68. The electrode assembly of embodiment 62, wherein x is about 6.

[0262] Embodiment 69. The electrode assembly of embodiment 62, wherein x is about 7.

[0263] Embodiment 70. The electrode assembly of embodiment 62, wherein x is about 8.

[0264] Embodiment 71. The electrode assembly of embodiment 62, wherein x is about 9.

[0265] Embodiment 72. The electrode assembly of embodiment 62, wherein x is about 10.

[0266] Embodiment 73. The electrode assembly of embodiment 62, wherein x is about 11.

[0267] Embodiment 74. The electrode assembly of embodiment 62, wherein x is about 12.

[0268] Embodiment 75. The electrode assembly of embodiment 62, wherein x is about 13.

[0269] Embodiment 76. The electrode assembly of embodiment 62, wherein x is about 14.

[0270] The electrode assembly of embodiment 62, wherein embodiment 77.x is about 15.

[0271] Embodiment 78. An electrode assembly according to any one of the preceding embodiments, wherein the resistive adhesive layer is not a fuse.

[0272] Embodiment 79. A secondary battery comprising an electrode assembly described in any one of the preceding embodiments.

[0273] Embodiment 80. A secondary battery as described in embodiment 79, wherein the electrode assembly is contained within a hermetically sealed enclosure.

[0274] Embodiment 81. A secondary battery as described in embodiment 79, wherein the electrode assembly is housed in a hermetically sealed enclosure, and the hermetically sealed enclosure is a pouch.

[0275] Embodiment 82. A secondary battery as described in embodiment 79, wherein the electrode assembly is contained in a hermetically sealed enclosure, and the second surface of the electrode bus bar and the hermetically sealed enclosure are in contact with a thermally conductive material.

[0276] Embodiment 83. An electrode assembly or secondary battery described in any one of the preceding embodiments, wherein (i) a member of the electrode structure assembly is an anode structure and a member of the counter electrode structure assembly is a cathode structure, or (ii) a member of the electrode structure assembly is a cathode structure and a member of the electrode structure assembly is an anode structure.

[0277] Embodiment 84. An electrode assembly or secondary battery described in any one of the preceding embodiments, wherein a member of the electrode structure assembly is an anode structure including an anode active material layer, and a member of the counter electrode structure assembly is a cathode structure including a cathode active material layer.

[0278] Embodiment 85. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the carrier ions are contained within a hermetically sealed battery enclosure.

[0279] Embodiment 86. The members of the assembly of the electrode structure are selected from the group consisting of carbon materials, graphite, soft or hard carbon, metals, semimetals, alloys, oxides, compounds capable of forming alloys with lithium, tin, lead, magnesium, aluminum, boron, gallium, silicon, Si / C composites, Si / graphite blends, SiOx, porous Si, intermetallic Si alloys, indium, zirconium, germanium, bismuth, cadmium, antimony, silver, zinc, arsenic, hafnium, yttrium, lithium, sodium, lithium titanate, palladium, lithium metal, carbon, petroleum coke, activated carbon, graphite, silicon compounds, silicon alloys, tin compounds, non-graphitized carbon, graphitic carbon, Li x Fe2O3(0≦x≦1), Li x WO2(0≦x≦1), Sn x Me 1-x Me' y O z(Me: Mn, Fe, Pb, Ge; Me′: Al, B, P, Si, elements found in Group 1, Group 2, and Group 3 of the periodic table, halogens; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8), lithium alloys, silicon-based alloys, tin-based alloys; metal oxides, SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5, conductive polymers, polyacetylene, Li-Co-Ni-based materials, crystalline graphite, natural graphite, synthetic graphite, amorphous carbon, Kish graphite, pyrolytic carbon, mesophase pitch-based carbon fibers, mesocarbon microbeads, mesophase pitch, graphitized carbon fibers, high-temperature sintered carbon, petroleum, coke derived from coal tar pitch, tin oxide, titanium nitrate, lithium metal film, alloys of lithium, and one or more types of metals selected from the group consisting of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al, and Sn, Si, Al, C, Pt, Sn, Pb, Ir, Ni, Cu, Ti, Na, K, Rb, Cs, Fr, Be, Ca, Sr, Sb, Ba, Ra, Ge, Zn, Bi, In, Mg, Ga, Cd, metal compounds capable of alloying and / or intercalating with lithium selected from any of them, Sn alloys, Al alloys, metal oxides capable of doping and undoping lithium ions, SiO v (0 < v < 2), composites containing SnO2, vanadium oxide, lithium vanadium oxide, metal compounds and carbon materials, Si-C composites, Sn-C composites, transition metal oxides, Li4 / 3Ti5 / 3O4, SnO, carbonaceous materials, graphite carbon fibers, resin calcined carbon, pyrolytic vapor grown carbon, cork, mesocarbon microbeads ("MCMB"), furfuryl alcohol resin calcined carbon, polyacene, pitch-based carbon fibers, vapor grown carbon fibers, or natural graphite, and formula Na disposed between layers of layered carbonaceous materials x Sn y-z M z(where M is Ti, K, Ge, P, or a combination thereof, 0 < x ≦ 15, 1 ≦ y ≦ 5, and 0 ≦ z ≦ 1, and is any one of the above-mentioned oxides, alloys, nitrides, fluorides), and any combination of any of the above, and an anode active material containing any one of them, an electrode assembly or a secondary battery according to any one of the preceding embodiments.

[0280] Embodiment 87. An electrode assembly or a secondary battery according to any one of the preceding embodiments, wherein the anode active material contains at least one of lithium metal, a lithium metal alloy, silicon, a silicon alloy, silicon oxide, tin, a tin alloy, tin oxide, and a carbon-containing material.

[0281] Embodiment 88. An electrode assembly or a secondary battery according to any one of the preceding embodiments, wherein the anode active material contains at least one of silicon and silicon oxide.

[0282] Embodiment 89. An electrode assembly or a secondary battery according to any one of the preceding embodiments, wherein the anode active material contains at least one of lithium and a lithium metal alloy.

[0283] Embodiment 90. An electrode assembly or a secondary battery according to any one of the preceding embodiments, wherein the anode active material contains a carbon-containing material.

[0284] Embodiment 91. An electrode assembly or a secondary battery according to any one of the preceding embodiments, wherein a member of the aggregate of electrically insulating separators contains a microporous separator material permeated with a non-aqueous liquid electrolyte.

[0285] Embodiment 92. An electrode assembly or a secondary battery according to any one of the preceding embodiments, wherein a member of the aggregate of electrically insulating separators contains a solid electrolyte.

[0286] Embodiment 93. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the members of the electrically insulating separator assembly comprise a ceramic material, a glass, or a garnet material.

[0287] Embodiment 94. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrode assembly comprises an electrolyte selected from the group consisting of a non-aqueous liquid electrolyte, a gel electrolyte, a solid electrolyte, and combinations thereof.

[0288] Embodiment 95. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrode assembly comprises a liquid electrolyte.

[0289] Embodiment 96. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrode assembly comprises an aqueous liquid electrolyte.

[0290] Embodiment 97. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrode assembly comprises a non-aqueous liquid electrolyte.

[0291] Embodiment 98. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrode assembly comprises a gel electrolyte.

[0292] Embodiment 99. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrically insulating separator comprises a solid electrolyte.

[0293] Embodiment 100. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrically insulating separator comprises a solid polymer electrolyte.

[0294] Embodiment 101. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrically insulating separator comprises a solid inorganic electrolyte.

[0295] Embodiment 102. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrically insulating separator comprises a solid organic electrolyte.

[0296] Embodiment 103. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrically insulating separator comprises a ceramic electrolyte.

[0297] Embodiment 104. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrically insulating separator comprises an inorganic electrolyte.

[0298] Embodiment 105. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrically insulating separator comprises a ceramic.

[0299] Embodiment 106. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrically insulating separator comprises a garnet material.

[0300] Embodiment 107. An electrode assembly or a secondary battery according to any one of the preceding embodiments, comprising an electrolyte selected from the group consisting of an aqueous electrolyte, a non-aqueous liquid electrolyte, a solid polymer electrolyte, a solid ceramic electrolyte, a solid glass electrolyte, a solid garnet electrolyte, a gel polymer electrolyte, an inorganic solid electrolyte, and a molten-type inorganic electrolyte.

[0301] Embodiment 108. A member of the counter electrode structure assembly comprises a cathode active material including at least one of a transition metal oxide, a transition metal sulfide, a transition metal nitride, a lithium transition metal oxide, a lithium transition metal sulfide, and a lithium transition metal nitride (including transition metal oxides, transition metal sulfides, and transition metal nitrides having a metal element with a d-shell or an f-shell), and / or the metal element is selected from the group consisting of Sc, Y, lanthanides, actinides, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pb, Pt, Cu, Ag, and Au, LiCoO, LiNi 0.5 Mn 1.5 O4, Li(Nix Co y Al z )O2, LiFePO4, Li2MnO4, V2O5, molybdenum oxysulfide, phosphates, silicates, vanadates, sulfur, sulfur compounds, oxygen (air), Li(Ni x Mn y Co z )O2, lithium-containing compounds including metal oxides or metal phosphates, compounds containing lithium, cobalt, and oxygen (e.g., LiCoO2), compounds containing lithium, manganese, and oxygen (e.g., LiMn2O4), compounds containing lithium iron and phosphate (e.g., LiFePO), lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron phosphate, lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), substituted compounds with one or more transition metals, lithium manganese oxide, Li 1+x Mn 2-x O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2, lithium copper oxide (Li2CuO2), vanaum oxide, LiV3O8, LiFe3O4, V2O5, Cu2V2O7, LiNi 1-x M x Ni-site type lithium nickel oxide, LiMnO2 (wherein M=Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x=0.01 to 0.3), 2-x M x Lithium manganese composite oxides represented by the chemical formula Li2Mn3MO8 (wherein M=Co, Ni, Fe, Cr, Zn, or Ta, and x=0.01 to 0.1), Li2Mn3MO8 (wherein M=Fe, Co, Ni, Cu, or Zn), LiMn2O4 in which part of the Li is substituted with an alkaline earth metal ion, disulfide compounds, Fe2(MoO4)3, and lithium metal phosphates having an olivine crystal structure represented by formula 2: Li 1+a Fe 1-x M′ x (PO 4-b )X b(where M’ is at least one selected from Al, Mg, Ni, Co, Mn, Ti, Ga, Cu, V, Nb, Zr, Ce, In, Zn, and Y; X is at least one selected from F, S, and N; -0.5 ≦ a ≦ +0.5, 0 ≦ x ≦ 0.5, and 0 ≦ b ≦ 0.1), LiFePO4, Li(Fe, Mn)PO4, Li(Fe, Co)PO4, Li(Fe, Ni)PO4, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, LiNi 1-y Co y O2, LiCo 1-y Mn y O2, LiNi 1-y Mn y O2 (0 ≦ y ≦ 1), Li(Ni a Co b Mn c )O4 (0 < a < 2, 0 < b < 2, 0 < c < 2, and a + b + c = 2), LiMn 2-z Ni z O4, LiMn 2-z Co z O4 (0 < z < 2), LiCoPO4, and LiFePO4, elemental sulfur (S8), sulfur-based compounds, Li2S n (n ≧ 1), organic sulfur compounds, carbon-sulfur polymers ((C2S x ) n : x = 2.5~50, n ≧ 2), oxides of lithium and zirconium, composite oxides of lithium and metals (cobalt, manganese, nickel, or combinations thereof), Li a A 1-b M b D2 (where 0.90 ≦ a ≦ 1, and 0 ≦ b ≦ 0.5), Li a E 1-b M b O 2-c D c (where 0.90 ≦ a ≦ 1, 0 ≦ b ≦ 0.5, and 0 ≦ c ≦ 0.05), LiE 2-b M b O 4-c D c (where 0 ≦ b ≦ 0.5, and 0 ≦ c ≦ 0.05), Li a Ni 1-b-c Co b M c D a(wherein, 0.90≦a≦1, 0≦b≦0.5, 0≦c≦0.05, and 0 <a≦2)、Li a Ni 1-b-c Co b M c O 2-a X a (wherein, 0.90≦a≦1, 0≦b≦0.5, 0≦c≦0.05, and 0 <a<2)、Li a Ni 1-b-c Co b M c O 2-a X2 (wherein 0.90≦a≦1, 0≦b≦0.5, 0≦c≦0.05, and 0 <a<2)、Li a Ni 1-b-c Mn b M c D a (wherein, 0.90≦a≦1, 0≦b≦0.5, 0≦c≦0.05, and 0 <a≦2)、Li a Ni 1-b-c Mn b M c O 2-a X a (wherein, 0.90≦a≦1, 0≦b≦0.5, 0≦c≦0.05, and 0 <a<2)、Li a Ni 1-b-c Mn b M c O 2-a X2 (wherein 0.90≦a≦1, 0≦b≦0.5, 0≦c≦0.05, and 0 <a<2)、Li a Ni b E c G d O2 (wherein 0.90≦a≦1, 0≦b≦0.9, 0≦c≦0.5, and 0.001≦d≦0.1), Li a Ni b Co c Mn d GeO2 (wherein 0.90≦a≦1, 0≦b≦0.9, 0≦c≦0.5, 0≦d≦0.5, and 0.001≦e≦0.1), Li a NiG b O2 (wherein 0.90≦a≦1 and 0.001≦b≦0.1), Li a CoG b O2 (wherein 0.90≦a≦1 and 0.001≦b≦0.1), Li a MnG bO2 (wherein 0.90≦a≦1 and 0.001≦b≦0.1), Li a Mn2G b O4 (wherein 0.90≦a≦1 and 0.001≦b≦0.1), QO2, QS2, LiQS2, V2O5, LiV2O5, LiX′O2, LiNiVO4, Li (3-f) J2(PO4)3(0≦f≦2);Li (3-f) Fe2(PO4)3 (0≦f≦2), LiFePO4, (A is Ni, Co, Mn, or a combination thereof; M is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; X is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; X' is Cr, V, Fe, Sc, Y, or a combination thereof; and J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof), LiCoO2, LiMn x O 2x (x=1 or 2), LiNi 1-x Mn x O 2x (0 <x<1)、LiNi 1-x-y Co x Mn y O2 (0≦x≦0.5, 0≦y≦0.5), FePO4, lithium compounds, lithium cobalt oxide, lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide, lithium nickel cobalt manganese oxide, lithium manganese oxide, lithium iron phosphate, nickel sulfide, copper sulfide, sulfur, iron oxide, vanadium oxide, sodium-containing materials, formula NaM 1 a O2 (in the formula, M 1 is at least one transition metal element, and is an oxide of 0≦a<1) 、 NaFeO2, NaMnO2, NaNiO2, NaCoO2, formula NaMn 1-a M 1 a O2 (in the formula, M 1is at least one transition metal element, and is represented by 0≦a<1), an oxide, Na[Ni 1 / 2 Mn 1 / 2 ]O2, Na 2 / 3 [Fe 1 / 2 Mn 1 / 2 ]O2, Na 0.44 Mn 1-a M 1 a O2 (in the formula, M 1 is at least one transition metal element, and is represented by an oxide represented by 0≦a<1), Na 0.7 Mn 1-a M 1 a O 2.05 an (wherein M 1 is at least one transition metal element, and is represented by an oxide represented by 0≦a<1), Na b M 2 c Si 12 O 30 (In the formula, M 2 is at least one transition metal element, and 2≦b≦6, and 2≦c≦5), an oxide represented by Na6Fe2Si 12 O 30 , Na2Fe5Si 12 O (where M 2 is at least one transition metal element, 2≦b≦6, and 2≦c≦5), Na d M 3 e SiO 18 (In the formula, M 3 is at least one transition metal element, 3≦d≦6, and 1≦e≦2), Na2Fe2Si6O 18 , Na2MnFeSi6O 18 (In the formula, M 3 is at least one transition metal element, 3≦d≦6, and 1≦e≦2), Na f M 4 g Si2O6 (in the formula, M 4is at least one element selected from transition metal elements, magnesium (Mg), and aluminum (Al), where 1≦f≦2 and 1≦g≦2), phosphate, Na2FeSiO6, NaFePO4, Na3Fe2(PO4)3, Na3V2(PO4)3, Na4Co3(PO4)2P2O7, borate, NaFeBO4 or Na3Fe2(BO4)3, fluoride, Na h M 5 F6 (in the formula, M 5 is at least one transition metal element, 2≦h≦3), Na3FeF6, Na2MnF6, fluorophosphates, Na3V2(PO4)2F3, Na3V2(PO4)2FO2, NaMnO2, Na[Ni 1 / 2 Mn 1 / 2 ]O2, Na 2 / 3 [Fe 1 / 2 Mn 1 / 2 ]O2, Na3V2(PO4)3, Na4Co3(PO4)2P2O7, Na3V2(PO4)2F3, and / or Na3V2(PO4)2FO2, and any complex oxides and / or other combinations of the foregoing.

[0302] Embodiment 109. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the negative electrode active material comprises at least one of a transition metal oxide, a transition metal sulfide, a transition metal nitride, a transition metal phosphate, and a transition metal nitride.

[0303] Embodiment 110. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the negative electrode active material comprises a transition metal oxide containing lithium and at least one of cobalt and nickel.

[0304] Embodiment 111. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the member of the electrode structure assembly includes an anode current collector comprising at least one of copper, nickel, aluminum, stainless steel, titanium, palladium, sintered carbon, calcined carbon, indium, iron, magnesium, cobalt, germanium, lithium, copper or stainless steel carbon, nickel, titanium, a silver surface treatment material, an aluminum-cadmium alloy, and / or alloys thereof.

[0305] Embodiment 112. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the members of the electrode structure assembly include an anode current collector comprising at least one of copper, nickel, stainless steel, and alloys thereof.

[0306] Embodiment 113. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the counter electrode structure comprises a cathode current collector comprising at least one of stainless steel, aluminum, nickel, titanium, burnt carbon, sintered carbon, carbon of aluminum or stainless steel, nickel, titanium, silver surface-treated material, or an alloy thereof.

[0307] Embodiment 114. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the cathode current collector comprises at least one of stainless steel, aluminum, nickel, titanium, baked carbon, sintered carbon, carbon of aluminum or stainless steel, a surface-treated material with silver, or an alloy thereof.

[0308] Embodiment 115. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the cathode current collector comprises aluminum.

[0309] Embodiment 116. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrical resistance is increased without completely detaching both the electrode bus bar and the electrode collector from the adhesive layer.

[0310] Embodiment 117. An electrode assembly or secondary battery described in any one of the preceding embodiments, wherein the electrode bus bar is configured by a design that bends, distorts, or deforms above a transition temperature to at least partially detach the electrode bus bar from at least one of the electrode current collector and the adhesive layer.

[0311] Embodiment 118. An electrode assembly as described in embodiment 117, wherein the electrode bus bar comprises a bimetal.

[0312] Embodiment 118. An electrode assembly as described in embodiment 117, wherein the electrode bus bar comprises trimetal.

[0313] Embodiment 119. An electrode assembly as described in embodiment 117, wherein the electrode bus bar comprises nitinol.

[0314] Embodiment 120. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the electrode current collector is configured by a design that bends, distorts, or deforms at or above a transition temperature, thereby at least partially detaching the electrode current collector from at least one of the electrode bus bar and the adhesive layer.

[0315] Embodiment 121. An electrode assembly as described in embodiment 120, wherein the electrode current collector comprises a bimetal.

[0316] Embodiment 122. An electrode assembly as described in embodiment 120, wherein the electrode current collector comprises a trimetal.

[0317] Embodiment 123. An electrode assembly as described in embodiment 120, wherein the electrode current collector comprises nitinol.

[0318] Embodiment 124. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is from about 60°C to about 125°C.

[0319] Embodiment 125. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 60°C.

[0320] Embodiment 126. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 65°C.

[0321] Embodiment 127. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 70°C.

[0322] Embodiment 128. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 75°C.

[0323] Embodiment 129. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 80°C.

[0324] Embodiment 130. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 85°C.

[0325] Embodiment 131. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 90°C.

[0326] Embodiment 132. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 95°C.

[0327] Embodiment 133. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 100°C.

[0328] Embodiment 134. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 105°C.

[0329] Embodiment 135. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 110°C.

[0330] Embodiment 136. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 115°C.

[0331] Embodiment 137. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 120°C.

[0332] Embodiment 138. An electrode assembly or secondary battery according to any one of the preceding embodiments, wherein the transition temperature is about 125°C.

[0333] Embodiment 139. An electrode assembly for cycling between a charged state and a discharged state, the electrode assembly being a collection of unit cells stacked on top of each other in a stacking direction, each member of the collection of unit cells including an electrode structure, a separator structure, and a counter electrode structure, the electrode structure including an electrode current collector and an electrode active material layer, the electrode structure extending in a longitudinal direction perpendicular to the stacking direction, an end portion of the electrode current collector extending in the longitudinal direction past an outer surface of the electrode active material layer and the separator structure, and the counter electrode structure including a counter electrode current collector and a counter electrode active material layer, the counter electrode structure extending in a longitudinal direction perpendicular to the stacking direction. an electrode bus bar, the electrode bus bar extending in a stacking direction and having a first surface and a second surface opposite the first surface, the first surface being positioned adjacent to an end portion of an electrode current collector, the first surface being attached to the end portion of the electrode current collector through the adhesive layer, wherein (i) the first surface of the electrode bus bar and an outer surface of the electrode active material layer are separated by a separation distance, and (ii) the separation distance between the first surface of the electrode bus bar and the outer surface of the electrode active material layer changes in response to at least one of an electrical short circuit and a current passing through the adhesive layer.

[0334] Embodiment 140. The members of the electrode structure assembly are selected from the group consisting of carbon materials, graphite, soft or hard carbon, metals, semimetals, alloys, oxides, compounds capable of forming alloys with lithium, tin, lead, magnesium, aluminum, boron, gallium, silicon, Si / C composites, Si / graphite blends, SiOx, porous Si, intermetallic Si alloys, indium, zirconium, germanium, bismuth, cadmium, antimony, silver, zinc, arsenic, hafnium, yttrium, lithium, sodium, lithium titanate, palladium, lithium metal, carbon, petroleum coke, activated carbon, graphite, silicon compounds, silicon alloys, tin compounds, non-graphitized carbon, graphitic carbon, Li. x Fe2O3(0≦x≦1), Li x WO2(0≦x≦1), Sn x Me 1-x Me' y O z(Me: Mn, Fe, Pb, Ge; Me′: Al, B, P, Si, elements found in Group 1, Group 2, and Group 3 of the periodic table, halogens; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8), lithium alloys, silicon-based alloys, tin-based alloys; metal oxides, SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5, conductive polymers, polyacetylene, Li-Co-Ni-based materials, crystalline graphite, natural graphite, synthetic graphite, amorphous carbon, Kish graphite, pyrolytic carbon, mesophase pitch-based carbon fibers, mesocarbon microbeads, mesophase pitch, graphitized carbon fibers, high-temperature sintered carbon, petroleum, coke derived from coal tar pitch, tin oxide, titanium nitrate, lithium metal film, alloys of lithium, and one or more types of metals selected from the group consisting of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al, and Sn, metals that can be alloyed and / or intercalated with lithium selected from any of Si, Al, C, Pt, Sn, Pb, Ir, Ni, Cu, Ti, Na, K, Rb, Cs, Fr, Be, Ca, Sr, Sb, Ba, Ra, Ge, Zn, Bi, In, Mg, Ga, Cd, Sn alloys, Al alloys, metal oxides capable of doping and undoping lithium ions, SiO v (0 < v < 2), composites containing SnO2, vanadium oxide, lithium vanadium oxide, metal compounds, and carbon materials, Si-C composites, Sn-C composites, transition metal oxides, Li4 / 3Ti5 / 3O4, SnO, carbonaceous materials, graphite carbon fibers, resin-baked carbon, pyrolytic vapor-grown carbon, cork, mesocarbon microbeads ("MCMB"), furfuryl alcohol resin-baked carbon, polyacene, pitch-based carbon fibers, vapor-grown carbon fibers, or natural graphite, and the formula Na disposed between the layers of the layered carbonaceous material x Sn y-z M z(where M is Ti, K, Ge, P, or a combination thereof, 0 < x ≦ 15, 1 ≦ y ≦ 5, and 0 ≦ z ≦ 1, and is any one of the above-mentioned oxides, alloys, nitrides, fluorides), and any combination of any of the above-mentioned, An electrode assembly or a secondary battery according to any one of the preceding embodiments, comprising an anode active material containing any one of them.

[0335] This written specification discloses the invention, including the best mode, using examples, and enables those skilled in the art to practice the invention, including making and using any device or system and implementing any incorporated method. The patentable scope of the present invention is defined by the claims and may include other examples contemplated by those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal words of the claims, or if they include equivalent structural elements with differences that are not substantially different from the literal words of the claims.

Claims

1. An electrode assembly that cycles between a charged state and a discharged state, Unit cells stacked on top of each other in the stacking direction, wherein each of the unit cells includes an electrode structure, a separator structure, and a counter electrode structure. The electrode structure includes an electrode current collector and an electrode active material layer, and the electrode structure extends in a longitudinal direction perpendicular to the stacking direction. The unit cell includes an electrode current collector, and each electrode current collector of the electrode current collector corresponds to the unit cell. Each of the electrode current collectors has an end extending in the longitudinal direction beyond the outer surface of the electrode active material layer and the separator structure, and each electrode current collector has an end included in the end. The counter electrode structure includes a counter electrode current collector and a counter electrode active material layer, and the counter electrode structure extends in the longitudinal direction, forming a unit cell. An adhesive layer containing a resistant polymer material, An electrode assembly comprising an electrode busbar extending in the stacking direction and having a first surface and a second surface opposite to the first surface, wherein the first surface is adjacent to the end of the electrode current collector, and at least a portion of the first surface is attached to the end via the adhesive layer, and the adhesive layer is configured to (a) adhere to the electrode busbar and the electrode current collector below the transition temperature, and (b) at least partially melt above the transition temperature to increase the electrical resistance between the electrode busbar and the electrode current collector.

2. (i) Each of the unit cells has ionic resistance, and (ii) The adhesive layer is configured to at least partially melt when an electrical short circuit is formed in a first unit cell of the unit cells, wherein the electrical short circuit has an electrical resistance less than the ionic resistance of the first unit cell in which the electrical short circuit is formed.

3. (i) Each of the unit cells has a capacity C, and (ii) the adhesive layer is configured to be at least partially melted by passing a current of at least x times the capacity C of the first unit cell through the adhesive layer of the first unit cell.

4. The electrode assembly according to claim 1, wherein the resistive polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to at least partially melt at a temperature above the transition temperature to increase the bulk resistivity of the adhesive layer.

5. The electrode assembly according to claim 1, wherein the resistant polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to at least partially melt at a temperature above the transition temperature to increase the interfacial resistance between the adhesive layer and at least one of the electrode busbar and the electrode current collector.

6. The electrode assembly according to claim 1, wherein the resistive polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to at least partially melt at a temperature above the transition temperature to reduce contact of the conductive material within a large portion of the adhesive layer and increase the volume resistivity of the adhesive layer.

7. The electrode assembly according to claim 1, wherein the resistant polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to (a) at least partially melt at a temperature above the transition temperature, and (b) flow, permeate, or flow and permeate at the interfaces of each portion of the conductive material.

8. The electrode assembly according to claim 1, wherein the resistant polymer material comprises a polymer and a conductive material suspended in the polymer, and the polymer is configured to (a) at least partially melt at a temperature above the transition temperature, and (b) flow, permeate, or flow and permeate at the interface between the adhesive layer and at least one of the electrode busbar and the electrode current collector.

9. The electrode assembly according to claim 1, wherein the adhesive layer is configured to at least partially carbonize at a temperature above the transition temperature to increase the electrical resistance between the electrode busbar and the electrode current collector.

10. The electrode assembly according to claim 1, wherein the adhesive layer is configured to be at least partially carbonized at a temperature above the transition temperature to form an electrical insulating layer between (a) the adhesive layer and (b) at least one of the electrode busbar and the electrode current collector.

11. A secondary battery comprising the electrode assembly according to claim 1, wherein the electrode assembly is housed in a sealed housing, and a thermally conductive material is in contact with both (a) the second surface of the electrode busbar and (b) the sealed housing.

12. An electrode assembly that cycles between a charged state and a discharged state, Unit cells stacked on top of each other in the stacking direction, wherein each of the unit cells includes an electrode structure, a separator structure, and a counter electrode structure. The electrode structure includes an electrode current collector and an electrode active material layer, and the electrode structure extends in a longitudinal direction perpendicular to the stacking direction. The unit cell includes an electrode current collector, and each electrode current collector of the electrode current collector corresponds to the unit cell. Each of the electrode current collectors has an end extending in the longitudinal direction beyond the outer surface of the electrode active material layer and the separator structure, and each electrode current collector has an end included in the end. The counter electrode structure comprises a counter electrode current collector and a counter electrode active material layer, and the counter electrode structure extends in a longitudinal direction perpendicular to the stacking direction, forming a unit cell. An adhesive layer containing a resistant polymer material, An electrode assembly comprising an electrode busbar extending in the stacking direction and having a first surface and a second surface opposite to the first surface, wherein the first surface is positioned adjacent to the end of the electrode current collector, and the first surface is attached to at least a portion of the end of the electrode current collector via the adhesive layer, and the resistant polymer material includes at least one phase change element configured to expand the volume of the adhesive layer above a transition temperature, the adhesive layer having a first volume below the transition temperature, and the adhesive layer expanding from the first volume to a second volume above the transition temperature to increase the electrical resistance between the electrode busbar and the electrode current collector.

13. (i) Each of the unit cells has ionic resistance, and (ii) The adhesive layer is configured to expand from the first volume to the second volume at or above the transition temperature when an electrical short circuit is formed in the first unit cell of the unit cells, and the electrical short circuit has an electrical resistance smaller than the ionic resistance of the first unit cell in which the electrical short circuit is formed.

14. (i) Each of the unit cells has a capacity C, and (ii) the adhesive layer is configured to expand from the first volume to the second volume at or above the transition temperature when a current passes through the adhesive layer of the first unit cell of the unit cell at a current amount at least x times the capacity C of the first unit cell of the unit cell.

15. (i) The electrode busbar and the electrode current collector are configured to adhere to the adhesive layer below the transition temperature, and (ii) at least one of the electrode busbar and the electrode current collector is configured to separate at least partially from the adhesive layer above the transition temperature.

16. A secondary battery comprising the electrode assembly according to claim 12, wherein the electrode assembly is housed in a sealed housing and a thermally conductive material is in contact with the second surface of the electrode busbar and the sealed housing.

17. An electrode assembly that cycles between a charged state and a discharged state, Unit cells stacked on top of each other in the stacking direction, wherein each of the unit cells includes an electrode structure, a separator structure, and a counter electrode structure. The electrode structure includes an electrode current collector and an electrode active material layer, and the electrode structure extends in a longitudinal direction perpendicular to the stacking direction. The unit cell includes an electrode current collector, and each electrode current collector of the electrode current collector corresponds to the unit cell. Each of the electrode current collectors has an end extending in the longitudinal direction beyond the outer surface of the electrode active material layer and the separator structure, and each electrode current collector has an end included in the end. The counter electrode structure includes a counter electrode current collector and a counter electrode active material layer, and the counter electrode structure extends in the longitudinal direction, forming a unit cell. An adhesive layer containing a resistant polymer material, An electrode assembly comprising an electrode busbar extending in the stacking direction and having a first surface and a second surface opposite to the first surface, wherein the first surface is positioned adjacent to at least a portion of the end of the electrode current collector, the first surface is attached to the end of the electrode current collector via the adhesive layer, the electrode busbar and the electrode current collector are configured to adhere to the adhesive layer below a transition temperature, and (i) at least one of the electrode busbar and (ii) the electrode current collector is configured to separate at least partially from the adhesive layer above the transition temperature.

18. (i) Each of the unit cells has an ionic resistance, and (ii) at least one of the electrode busbar and the electrode current collector is configured to separate at least partially from the adhesive layer when an electrical short circuit is formed in the first unit cell of the unit cell, and the electrical short circuit has an electrical resistance smaller than the ionic resistance of the first unit cell of the unit cell in which the electrical short circuit is formed.

19. (i) Each of the group of unit cells has a capacitance C, and (ii) At least one of the electrode busbar and the electrode current collector is configured to separate at least partially from the adhesive layer of the first unit cell when a current passes through the adhesive layer of the first unit cell at a current amount at least x times the capacitance C of a member of the group of unit cells.

20. The electrode assembly according to claim 17, wherein the electrode busbar is configured to bend, warp, or deform at a temperature above the transition temperature, thereby separating the electrode busbar at least partially from (i) the electrode current collector and (ii) the adhesive layer.

21. The electrode assembly according to claim 20, wherein the electrode busbar comprises at least one of (i) bimetal, (ii) trimetal, and (iii) nitinol.

22. The electrode assembly according to claim 17, wherein the electrode current collector is configured to bend, warp, or deform at a temperature above the transition temperature, thereby separating the electrode current collector at least partially from (i) the electrode busbar and (ii) the adhesive layer.

23. The electrode assembly according to claim 22, wherein the electrode busbar comprises at least one of (i) bimetal, (ii) trimetal, and (iii) nitinol.

24. A secondary battery comprising the electrode assembly according to claim 17, wherein the electrode assembly is housed in a sealed housing and a thermally conductive material is in contact with the second surface of the electrode busbar and the sealed housing.

25. An electrode assembly that cycles between a charged state and a discharged state, A group of unit cells stacked on top of each other in the stacking direction, wherein each member of the group of unit cells includes an electrode structure, a separator structure, and a counter electrode structure. The electrode structure includes an electrode current collector and an electrode active material layer, and the electrode structure extends in a longitudinal direction perpendicular to the stacking direction. Each of the aforementioned unit cells includes an electrode current collector, and each electrode current collector is included in the plurality of electrode current collectors. Each of the electrode current collectors has an end extending in the longitudinal direction beyond the outer surface of the electrode active material layer and the separator structure, and each electrode current collector has an end including the end, The counter electrode structure includes a counter electrode current collector and a counter electrode active material layer, and the counter electrode structure extends in the longitudinal direction, forming a unit cell. An adhesive layer containing a resistant polymer material, An electrode assembly comprising an electrode busbar extending in the stacking direction and having a first surface and a second surface opposite to the first surface, wherein the first surface is positioned adjacent to the end of the electrode current collector and the first surface is attached to the end of the electrode current collector via the adhesive layer, wherein the first surface of the electrode busbar and the outer surface of the electrode active material layer are separated by a separation distance, and the separation distance between the first surface of the electrode busbar and the outer surface of the electrode active material layer changes in response to at least one of (i) an electrical short circuit and (ii) a current flowing through the adhesive layer.

26. (i) Each of the unit cells has ionic resistance, and (ii) the separation distance between the first surface of the electrode busbar and the outer surface of the electrode active material layer increases or decreases when an electrical short circuit is formed in the first unit cell of the unit cell, and the electrical short circuit has an electrical resistance less than the ionic resistance of the first unit cell in which the electrical short circuit is formed.

27. (i) Each of the unit cells has a capacity C, and (ii) when a current passes through the adhesive layer of the first unit cell at a current amount at least x times the capacity C of the first unit cell, the separation distance between the first surface of the electrode busbar and the outer surface of the electrode active material layer increases or decreases, where x is about 1 to about 15, the electrode assembly according to claim 25.

28. (i) Each of the unit cells has ionic resistance, (ii) The first surface of the electrode busbar and the end of the electrode current collector are separated by a separation distance, and (iii) The separation distance between the first surface of the electrode busbar and the end of the electrode current collector increases or decreases when an electrical short circuit is formed in the first unit cell of the unit cell, and the electrical short circuit has an electrical resistance smaller than the ionic resistance of the first unit cell in which the electrical short circuit is formed.

29. (i) Each of the unit cells has a capacity C, (ii) The first surface of the electrode busbar and the end of the electrode current collector are separated by a separation distance, and (iii) When a current passes through the adhesive layer of the first unit cell at a current amount of at least x times the capacity C of the first unit cell, the separation distance increases, where x is about 1 to about 15, the electrode assembly according to claim 25.

30. A secondary battery comprising the electrode assembly according to claim 25, wherein the electrode assembly is housed in a sealed housing, and the thermally conductive material is in contact with the second surface of the electrode busbar and the sealed housing.

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