Electrode assembly including a current limiter, secondary battery having such an electrode assembly, and method of testing

Abstract

An electrode assembly for cycling between charged and discharged states within a normal operating temperature range of minus 20 degrees Celsius (°C) to 80°C includes a group of unit cells, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. Each constituent unit of the group of unit cells includes an electrode structure, a separator structure, and a counter electrode structure. At least one constituent unit of the group of current limiters is electrically connected between the unit cell and the electrode bus bar or the counter electrode bus bar. For each unit cell, at least one constituent unit of the group of current limiters has a resistance sufficient to limit a current through the unit cell below a threshold current I when the electrode assembly is within a normal operating temperature range, the threshold current I being below a current that would induce thermal runaway of the unit cell.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 168,430, filed March 31, 2021, and U.S. Provisional Patent Application No. 63 / 202,922, filed June 30, 2021, the entire disclosures of which are incorporated herein by reference in their entireties.

[0002] The field of the disclosure relates generally to energy storage technologies, such as battery technologies. More specifically, 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 laminate structures, such as planar or spirally wound (i.e., jelly-roll) laminate structures, where the surface area of ​​each laminate is approximately equal to its geometric footprint (neglecting porosity and surface roughness).

[0005] FIG. 1 illustrates a cross-sectional view of a known layered-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 the positive electrode 20 by a 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 may be covered with another separator layer (not shown) over the negative electrode current collector 35, then rolled and placed in a can (not shown) to assemble battery 10. During the charging process, carrier ions (typically lithium) leave the positive electrode 20 and migrate through separator 30 into the negative electrode 25. Depending on the anode material used, the carrier ions either intercalate with the negative electrode material (e.g., locate in the matrix of the negative electrode material without forming an alloy) or form an alloy. During the discharge process, carrier ions leave the negative electrode 25 , migrate back through the separator 30 , and back into the positive electrode 20 .

[0006] Three-dimensional secondary batteries can provide increased capacity and long life compared to layered secondary batteries. Three-dimensional battery architectures (e.g., interdigitated electrode arrays) have been proposed in the literature to provide higher electrode surface area, higher energy and power density, improved battery capacity, and improved active material utilization compared to two-dimensional architectures (e.g., flat and spiral lamellae). For example, Long et al., "Three-dimensional battery architectures," Chemical Reviews, 2004, 104, 4463-4492, can serve to illustrate the state of the art in proposed three-dimensional battery architectures, and is therefore incorporated herein by reference as non-essential subject matter.

[0007] Energy storage devices, including secondary batteries, can release energy in an undesirable or uncontrolled manner through accidents, abuse, exposure to extreme conditions, etc. Building safety features into secondary batteries can mitigate 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 through temperature rise phenomena. Excessive heat and thermal runaway can occur due to electrolyte decomposition on overcharge and at high operating temperatures. In the case of high voltage cathode materials such as LiCoO2, thermal runaway can also occur due to oxygen evolution. In some cases, mechanical abuse can also short the active materials together, thereby resulting in thermal runaway. This can occur due to overcharging the battery, electrical shorting, or shorting 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 resistance having a positive temperature coefficient (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 excess current through the battery. For example, reference to PG Balakrishnan, R. Ramesh, and T. Prem Kumar, “Safety mechanisms in lithium-ion batteries,” Journal of Power Sources, 2006, 155, 401-414, may be useful in illustrating the state of the art of safety mechanisms in 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 delay between the flow of an overcurrent and the tripping of the fuse. This delay occurs because the fuse is usually activated by the heat generated when an overcurrent flows through the battery. Thus, in the case of a non-resettable fuse, the overcurrent flows through the battery for a period of time until the temperature experienced by the fuse reaches the temperature required to blow the fuse, or in the case of a resettable fuse using a PTC material, increases the resistance sufficiently to limit the current flowing through the battery. In some circumstances, the delay between the initiation of the overcurrent and the tripping of the fuse can result in failure of the fuse to prevent thermal runaway.

[0011] Furthermore, non-resettable fuses permanently disconnect at least a portion of the battery when the fuse trips, resulting in the battery being completely inoperable or operating at only a limited capacity, even if the fuse prevents thermal runaway and catastrophic failure.

[0012] Therefore, to address the problems of the known technology, it would be desirable to produce a three-dimensional battery that includes a current limiter to limit the current that can flow through the battery, independent of the temperature of the battery. Summary of the Invention

[0013] In one embodiment, a method for assembling an electrode assembly includes stacking a group of unit cells on top of each other in a stacking direction. Each unit of the group of unit cells includes 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 counter electrode structure including a counter electrode current collector and a counter electrode active material layer, the electrode structure and the counter electrode structure extending in a longitudinal direction perpendicular to the stacking direction, and end portions of the electrode current collector extending in the longitudinal direction beyond the electrode active material and separator structures. The method includes bending the end portions of each electrode current collector in a direction perpendicular to the longitudinal direction of the electrode structure to extend in or against the stacking direction. An electrode bus bar is positioned with a surface of the electrode bus bar adjacent to the end portion of the electrode current collector and extending in the stacking direction. Heat and pressure are applied to the electrode bus bar to bond the end portions of the electrode current collector to the bus bar via an adhesive layer including a resistive polymer material.

[0014] In another embodiment, an electrode assembly for cycling between a charged state and a discharged state includes a group of unit cells, an electrode bus bar, a counter electrode bus bar, and a group of current limiters. Each unit of the unit cell group includes an electrode structure, a separator structure, and a counter electrode structure, the electrode structure of each unit of the unit cell group having a capacity C and including an electrode current collector and an electrode active material layer, and the counter electrode structure of each unit of the unit cell group includes a counter electrode current collector and a counter electrode active material layer. For each unit of the unit cell group, (a) the electrode current collector of the electrode structure is electrically connected to the electrode bus bar, (b) the counter electrode current collector of the counter electrode structure is electrically connected to the counter electrode bus bar, and (c) the unit of the current limiter group is electrically connected (i) between the electrode current collector and the electrode bus bar, or (ii) between the counter electrode current collector and the counter electrode bus bar. Each unit of the unit cell group has a maximum charging voltage V between the electrode current collector and the counter electrode current collector. TOC and a unit cell resistance R determined at a non-zero frequency between the electrode current collector and the counter electrode current collector. blEach constituent unit of the current limiter group has a resistor R that limits the amount of current that can be conducted from the electrode bus bar or the counter electrode bus bar to the constituent unit of the unit cell group during discharge of the electrode assembly when there is an electrical short between the electrode and the counter electrode of one constituent unit of the unit cell group to a value I determined according to the following formula: cld Having:

number

[0015] R S is the hard short circuit resistance of the constituent elements of the unit cell group determined using the dry forced internal short circuit (FISC) test, and R t is the combined resistance of the electrode busbar and the counter electrode busbar determined at non-zero frequencies, and R cld has a nonzero value such that I c *R cld <0.5 Volts In the formula, I c is the 1C rate current.

[0016] In another embodiment, an electrode assembly for cycling between a charged state and a discharged state includes a group of unit cells, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. Each unit of the group of unit cells includes an electrode structure, a separator structure, and a counter electrode structure, the electrode structure of each unit of the group of unit cells includes an electrode current collector and an electrode active material layer, and the counter electrode structure of each unit of the group of unit cells includes a counter electrode current collector and a counter electrode active material layer. For each unit of the group of unit cells, (a) the electrode current collector of the electrode structure is electrically connected to the electrode bus bar, (b) the counter electrode current collector of the counter electrode structure is electrically connected to the counter electrode bus bar, and (c) the unit of the current limiter group is located at the electrical connection between (i) the electrode current collector and the electrode bus bar, or (ii) the counter electrode current collector and the counter electrode bus bar. Each unit of the group of current limiters includes a conductive adhesive, the conductive adhesive having a resistance of 0.25 ohms (Ω) or greater at 25 degrees Celsius (° C.).

[0017] In another embodiment, an electrode assembly for cycling between charged and discharged states within a normal operating temperature range of minus 20 degrees Celsius (°C) to 80°C, the electrode assembly comprising a group of unit cells, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. Each unit of the unit cell group comprises an electrode structure, a separator structure, and a counter electrode structure, the electrode structure of each unit of the unit cell group comprises an electrode current collector and an electrode active material layer, and the counter electrode structure of each unit of the unit cell group comprises a counter electrode current collector and a counter electrode active material layer. For each unit of the unit cell group, (a) the electrode current collector of the electrode structure is electrically connected to the electrode bus bar, (b) the counter electrode current collector of the counter electrode structure is electrically connected to the counter electrode bus bar, and (c) at least one unit of the current limiter group is electrically connected (i) between the electrode current collector and the electrode bus bar, or (ii) between the counter electrode current collector and the counter electrode bus bar. For each unit cell, at least one member of the current limiter group has sufficient resistance to limit the current through the unit cell below a threshold current I, which is below the current that would induce thermal runaway of the unit cell when the electrode assembly is within normal operating temperatures.

[0018] There are various refinements of the features noted in relation to the above-mentioned aspects. Further features may also be incorporated into the above-mentioned aspects. These refinements and additional features may be present individually or in any combination. For example, the various features discussed below in relation to any of the illustrated embodiments may be incorporated alone or in any combination into any of the above-mentioned aspects. [Brief description of the drawings]

[0019] [Figure 1] 1 is a cross-section of an existing layered battery. [Diagram 2] FIG. 1 is a simplified diagram of an exemplary electrode assembly for cycling between charged and discharged states in a secondary battery. [Figure 3A] FIG. 3 is a simplified diagram of an end of a 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 in FIG. 3A connected to a counter electrode bus bar. [Figure 4A] FIG. 3 is a top view of a pair of electrode structures of the electrode assembly of FIG. 2, with their current collectors attached to a bus bar via a current limiter. [Figure 4B] FIG. 4B is a side view of one of the electrode structures of FIG. 4A, the current collector of which is attached to a bus bar via a current limiter. [Diagram 5] FIG. 1 is a simplified diagram of an exemplary electrode assembly for cycling between charged and discharged states in a secondary battery. [Figure 6] FIG. 2 is a simplified schematic diagram of another exemplary electrode assembly for cycling between charged and discharged states in a secondary battery. [Figure 7] FIG. 2 is a simplified schematic diagram of yet another exemplary electrode assembly for cycling between charged and discharged states in a secondary battery. [Figure 8A] FIG. 2 is a simplified isometric view of an anode electrode structure for use in an electrode assembly. [Figure 8B] FIG. 2 is a simplified isometric view of a cathode electrode structure for use in the electrode assembly. [Figure 9] FIG. 2 is an isometric view of an exemplary stacked cell produced as part of the manufacture of a secondary battery. [Figure 10] FIG. 10 is a portion of a top view of the stacked cell shown in FIG. [Figure 11A] FIG. 10 is an isometric view of the stacked cell shown in FIG. 9 positioned at a packing station. [Figure 11B] FIG. 11B is an isometric view of the stacked cell shown in FIG. 11A with a battery package placed on top. [Figure 12] FIG. 2 is a simplified schematic of a unit cell of an electrode assembly being tested in a forced internal short circuit test. [Figure 13] FIG. 2 is a simplified diagram of a portion of another exemplary electrode assembly for cycling between charged and discharged states in a secondary battery. [Figure 14]1 is a side view electrode structure including a current collector of the electrode structure attached to a bus bar via a current limiter and an interface layer attached to the bus bar. [Figure 15] 1 is a side view electrode structure including a current collector of the electrode structure attached to a bus bar via a current limiter and an interface layer applied to the electrode current collector. [Figure 16] 1 is a side view electrode structure including a current collector of an electrode structure attached to a bus bar via a current limiter, an interface layer attached to the current electrode current collector, and an interface layer attached to the bus bar. [Figure 17] FIG. 13 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. 13 is a side view of one of the electrode structures in which the current collector of the electrode structure is attached to a busbar via a current limiter formed as a single layer without the use of slots in the current collector. [Figure 19] FIG. 13 is a side view of one of the electrode structures in which the current collector of the electrode structure is attached to the busbar via a separate current limiter formed as a single layer without the use of slots in the current collector.

[0020] Corresponding reference characters indicate corresponding parts throughout the drawings.

[0021] 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.

[0022] As used herein, "about" and "approximately" refer to plus or minus 10%, 5%, or 1% of the stated value. For example, in one case, about 250 μm includes 225 μm to 275 μm. As a further example, in one case, 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 to be modified in all cases by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and the 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.

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

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

[0025] "Cathode" as used herein in the context of a secondary battery refers to the positive electrode of the secondary battery.

[0026] As used herein, "cathode material" or "cathode active" means a material suitable for use as the positive electrode of a secondary battery.

[0027] "Conversion chemical active material" or "conversion chemical" refers to a material that undergoes a chemical reaction during the charge-discharge cycle of a secondary battery.

[0028] As used herein, a "counter electrode" may refer to the electrode opposite the negative or positive electrode (anode or cathode) of a secondary battery, unless the context explicitly indicates otherwise.

[0029] As used herein, a "counter electrode current collector" may refer to the current collector of either the negative or positive electrode (anode or cathode) of a secondary battery on the opposite side of the electrode, unless the context explicitly indicates otherwise.

[0030] A "cycle" as used herein 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 the battery 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., the charging state if the first state was discharging, or the discharging state if the first state was charging), 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 can include charging the battery from the discharging state to the charging state, as in a charging cycle, and then discharging back to the discharging state to complete the cycle. A single cycle can also include discharging the battery from the charging state to the discharging state, as in a discharging cycle, and then charging back to the charging state to complete the cycle.

[0031] As used herein, "electrochemically active material" means an anode active material or a cathode active material.

[0032] As used herein, an "electrode" may refer to either the negative or positive electrode (anode or cathode) of a secondary battery, unless the context explicitly indicates otherwise.

[0033] As used herein, "electrode current collector" may refer to the current collector of either the negative or positive electrode (anode or cathode) of a secondary battery, unless the context explicitly indicates otherwise.

[0034] As used herein, "electrode material" may refer to either anodic or cathodic materials, unless the context explicitly indicates otherwise.

[0035] As used herein, "electrode structure" may refer to an anode structure (e.g., a negative electrode structure) or a cathode structure (e.g., a positive electrode structure) suitable for use in a battery, unless the context explicitly indicates otherwise.

[0036] As used herein, "longitudinal axis", "lateral axis", and "vertical axis" refer to mutually perpendicular axes (i.e., each is perpendicular to the other). For example, the "longitudinal axis", "lateral axis", and "vertical axis" used herein are similar to a Cartesian coordinate system used to define three-dimensional aspects or orientations. As such, the description of the elements of the subject matter disclosed herein is not limited to the particular axes used to describe the three-dimensional orientation of the elements. Alternatively stated, the axes may be interchangeable when referring to three-dimensional aspects of the disclosed subject matter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] 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 the safety of the battery.

[0038] 2 is a simplified diagram of an exemplary electrode assembly 200 for cycling between charged and discharged states of a battery. The electrode assembly 200 includes a group of electrode structures 202, a group of counter electrode structures 204, a group of separator structures 205, a group of current limiters 206, an electrode bus bar 208, and a counter electrode bus bar 210. The exemplary embodiment is an electrode assembly suitable for use in a three-dimensional secondary battery, where the electrode structures 202 and the counter electrode structures 204 each extend primarily along the width W and height H of the assembly, and are separated from one another along the length (or longitudinal) direction L. In other embodiments, the electrode assembly 200 may be for use in a layered secondary battery.

[0039] There is a voltage difference V between adjacent electrode structures 202 and counter electrode structures 204, and the adjacent pair can be considered as a unit cell. Each unit cell has a capacity C determined by the structure and configuration of the electrode structures 202 and counter electrode structures 204. In an exemplary embodiment, each unit cell produces 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 to 5 volts, or any other suitable voltage. During cycling between charge and discharge, the voltage can vary, for example, from about 2.5 volts to about 4.35 volts. In an exemplary embodiment, the capacity C of the unit cell 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.

[0040] In the exemplary embodiment, the electrode structures 202 and counter electrode structures 204 are generally rectangular and arranged in an interdigitated configuration. That is, the electrode structures 202 and counter electrode structures 204 extend from opposing electrode bus bars 208 and counter electrode 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 in which the electrode assembly 200 is included) may have any of the shapes and / or arrangements described or shown in U.S. Patent No. 9,166,230, which is incorporated herein by reference in its entirety.

[0041] Each unit of the group 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 via a current limiter 206. The electrode structures 202 can be anodic or cathodic, but in an exemplary embodiment, all of the electrode structures 202 in the group are of the same type (anodic or cathodic). In some other embodiments, the electrode structures 202 can include anodic and cathodic structures. Each unit of the group 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. The counter electrode structures 204 are all of the same type (anodic or cathodic), in an exemplary embodiment, and are of the opposite type to the electrode structures 204. In some other embodiments, the counter electrode structures 202 can include anodic and cathodic structures. Although only two electrode structures 202 and two counter electrode structures 204 are shown in FIG. 2, the electrode assembly 200 may have any number of electrode structures 202 and counter electrode structures 204. The groups of electrode structures 202 and counter electrode structures 204 generally include the same number of units, but in some embodiments may include different numbers of electrode structures 202 and counter electrode structures 204. For example, some embodiments may start and end with the same electrode structure 202 or counter electrode structure, resulting in one or more electrode structures 202 or counter electrode structures. In some embodiments, the groups of electrode structures 202 and counter electrode structures 204 each include at least 20 units. Some embodiments include groups of electrode structures 202 and counter electrode structures 204 having about 10 units each, 10-25 units each, 25-250 units each, 25-150 units each, 50-150 units each, or up to 500 units each. In some embodiments, either the electrode structure 202 or the counter electrode structure 204 does not contain active material when discharged, and only the other of the counter electrode structure 204 or the electrode structure 202 contains active material when discharged.

[0042] The cathode-type electrode structure 202 or counter electrode structure 204 includes a cathode current collector 214 or 218. 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 4 By way of further example, in one such embodiment, the cathode current collector has a conductivity of at least about 10 5 The anode-type electrode structure 202 or the counter electrode structure 204 includes an 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.

[0043] The cathode-type 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 chemical active material, a conversion chemical active material, or a combination thereof.

[0044] Exemplary conversion chemical materials useful in the present disclosure include S (or the lithiated form LiS), LiF, Fe, Cu, Ni, FeF, FeO d F 3.2d , FeF3, CoF3, CoF2, CuF2, and NiF2, where 0≦d≦0.5.

[0045] Exemplary cathode active materials also include any of a wide range of intercalation type cathode active materials. For example, in the case of a lithium ion battery, the cathode active material may include a cathode active 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 an f-shell. Specific examples of such metal elements are 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 LiCoO2, LiNi 0.5 Mn 1.5 O4, Li(Ni x Co y Al z )O2, LiFePO4, Li2MnO4, V2O5, molybdate oxysulfide, phosphates, silicates, vanadates, sulfur, sulfur compounds, oxygen (air), Li(Ni x Mn y Co z ) O2, and combinations thereof.

[0046] Generally, the cathode active material has a thickness of at least about 20 um, whether electrode structure 202 or counter electrode structure 204 is a cathode type structure. For example, in one embodiment, the cathode active material layer has a thickness of at least about 40 um. By way of further example, in one such embodiment, the cathode active material has a thickness of at least about 60 um. By way of further example, in one such embodiment, the cathode active material has a thickness of at least about 100 um. Typically, however, the cathode active material has a thickness of less than about 90 um, or even less than about 70 um.

[0047] The anode-type electrode structure 202 or counter electrode structure 204 includes an active material 212 or 216 that is an anode active material. In general, the anode active material may be selected from the group consisting of: (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; and (c) Si, Ge, Sn, Pb, Sb, or other elements. (d) oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Bi, Zn, Al, Ti, Fe, Ni, Co, V, or Cd, and mixtures, composites, or lithium-containing composites thereof; (e) salts and hydroxides of Sn; (f) lithium titanate, lithium manganate, lithium aluminate, lithium-containing titanium oxides, lithium transition metal oxides, ZnCo2O4; (g) graphite and carbon particles; and (h) combinations thereof.

[0048] Exemplary anode active materials include graphite and soft or hard carbon, or carbon materials such as graphene (e.g., single-walled or multi-walled carbon nanotubes), or any of a range of metals, metalloids, alloys, oxides, nitrides, and compounds that can intercalate or form alloys with lithium. Specific examples of metals or metalloids that can constitute the anode material include graphite, tin, lead, magnesium, aluminum, boron, gallium, silicon, Si / C composites, Si / graphite blends, silicon oxide (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 includes aluminum, tin, or silicon, or oxides thereof, nitrides thereof, fluorides thereof, or other alloys thereof. In another exemplary embodiment, the anode active material comprises silicon, or an alloy or oxide thereof.

[0049] In one embodiment, the anode 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 introduced into or removed from the anode active material during charge and discharge processes. In general, the void volume fraction of the (each of) the anode active material layer is at least 0.1. Typically, however, the void volume fraction of the (each of) the anode active material layer is 0.8 or less. For example, in one embodiment, the void volume fraction of the (each of) the anode active material layer is about 0.15 to about 0.75. As a further example, in one embodiment, the void volume fraction of the (each of) the anode active material layer is about 0.2 to about 0.7. As a further example, in one embodiment, the void volume fraction of the (each of) the anode active material layer is about 0.25 to about 0.6.

[0050] Depending on the composition of the microstructured anode active material and the method of its formation, the microstructured anode active material may include macroporous, microporous, or mesoporous material layers, or combinations thereof, such as a combination of microporous and mesoporous, or 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 pore morphologies that can be linear, branched, or dendritic, and smooth or rough-walled. Furthermore, the void volume can include open or closed porosity, or a combination thereof. In one embodiment, the void volume includes open porosity, i.e., the anode active material includes porosity with openings at the lateral faces of the anode active material through which lithium ions (or other carrier ions) can enter or leave the anode active material, e.g., lithium ions can enter the anode active material through the pore openings after leaving the cathode active material. In another embodiment, the void volume includes closed porosity, i.e., the anode active material includes porosity that is enclosed by the anode active material. In general, open porosity can provide a greater interfacial surface area for carrier ions, while closed porosity tends to be less susceptible to solid electrolyte interfaces, while each provides room for expansion of the anode active material upon ingress of carrier ions. Thus, in certain embodiments, it is preferred that the anode active material include a combination of open and closed porosity.

[0051] In one embodiment, the anode active material comprises porous aluminum, tin or silicon, or alloys, oxides, or nitrides thereof. The porous silicon layer can be formed, for example, by anodization, by etching (e.g., by depositing a precious metal such as gold, platinum, silver, or gold / palladium on the surface of the 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. Furthermore, 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. As a 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 (e.g., nickel silicide), has a thickness of about 5 to about 100 micrometers, and has a porosity of about 0.15 to about 0.75.

[0052] In another embodiment, the anode active material comprises aluminum, tin or silicon fibers, or alloys of tin or silicon. The individual fibers may 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. The silicon fibers (nanowires) may be formed by, for example, 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. As a 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.

[0053] In yet another embodiment, the anode negative electrode (i.e., 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 about 0.05-5 mg / cm. 2 , for example, about 0.1 to 4 mg / cm 2 , or even about 0.5 to 3 mg / cm 2 The lithium particulate material may be applied to the negative electrode active material layer by spraying, loading, or otherwise disposing the lithium particulate material on the negative electrode active material layer at a loading of about 1000 μm or more. 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% in the cumulative volume-based particle size distribution curve. 50 ) can be measured, for example, using laser diffraction methods.

[0054] The anode-type electrode structure 202 or counter electrode structure 204 includes an anode current collector 214 or 218. Generally, the anode current collector has a thickness 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 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 10 ...

[0055] In one embodiment, the anode current collector, i.e., electrode current collector 214 or counter electrode current collector 218, whichever is of the anode type, 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, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material layer is at least 100:1 when there is an applied current to store energy in the device or an applied load to discharge the device. By way of further example, in some embodiments, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material layer is at least 500:1 when there is an applied current to store energy in the device or an applied load to discharge the device. By way of further example, in some embodiments, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material layer is at least 1000:1 when there is an applied current to store energy in the device or an applied load to discharge the device. By way of further example, in some embodiments, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material layer, when subjected to an applied current to store energy in the device or an applied load to discharge the device, is at least 5000:1. By way of further example, in some embodiments, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material layer, when subjected to an applied current to store energy in the device or an applied load to discharge the device, is at least 10000:1.

[0056] In general, the cathode-type current collector, i.e., electrode current collector 214 or counter electrode current collector 218, whichever 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 of gold, such as gold silicide. By way of further example, in one embodiment, the cathode current collector includes nickel or an alloy of nickel, such as nickel silicide.

[0057] Referring to FIG. 8A, each anode electrode structure, i.e., each electrode structure 202 of the anode type, or counter electrode structure 204, is aligned along the longitudinal axis (A E ) along the length (L E ) and width (W E ) and length L E and width W E The height (H E ) and.

[0058] Length L of the constituent unit of the anode electrode structure group E varies depending on the energy storage device and the intended use of the energy storage device. 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 As a further example, in one such embodiment, the constituent units of the anode group 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 units having a first length and one or more second electrode units having a second length other than the first. In yet another embodiment, the different lengths of the one or more first electrode units and the one or more second electrode units can be selected to accommodate a predetermined shape of the electrode assembly, such as a shape of the electrode assembly having different lengths along one or more of the longitudinal and / or transverse axes, and / or to provide a predetermined performance characteristic of the secondary battery.

[0059] Width W of the cathode electrode structure E The width W of each anode electrode structure will also vary depending on the energy storage device and the intended use of the energy storage device. In general, however, each anode electrode structure will typically have 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 units having a first width and one or more second electrode units having a second width other than the first. In yet another embodiment, the different widths of the one or more first electrode units and the one or more second electrode units may be selected to accommodate a predetermined shape of the electrode assembly, such as a shape of the electrode assembly having different widths along one or more of the longitudinal and / or lateral axes, and / or to provide a predetermined performance characteristic of the secondary battery.

[0060] Height H of the anode electrode structure E The height H of the anode electrode structure will vary depending on the energy storage device and the intended use of the energy storage device. In general, however, the anode electrode structure will typically have 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 EBy 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. E is 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 building blocks having a first height and one or more second electrode building blocks having a second height other than the first. In yet another embodiment, the different heights of the one or more first electrode building blocks and the one or more second electrode building blocks can be selected to accommodate a predetermined shape of the electrode assembly, such as a shape of the electrode assembly having different heights along one or more of the longitudinal and / or lateral axes, and / or to provide a predetermined performance characteristic of the secondary battery.

[0061] In general, the anode electrode structure has a width W E and the height H of the anode electrode structure E A length L substantially larger than each of E For example, in one embodiment, for each unit of the anode group, L E and W E and H E and each of the L E and W E and L are at least 5:1, respectively. E and H E and L are each at least 5:1. E and W E and H E and each of L is at least 10:1. E and W E and H E is at least 15:1. By way of further example, in one embodiment, for each unit of the anode population, L E and W E and H E Each of the ratios is at least 20:1.

[0062] In one embodiment, the height H of the anode electrode structure E and width WE and H are each at least 0.4:1. E and W E and H are at least 2:1, respectively, for each unit of the anode population. E and W E and H are each at least 10:1. E and W E The ratio of H to H is at least 20:1, respectively. E and W E and H are generally less than 1,000:1, respectively. For example, in one embodiment, 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, respectively.

[0063] Referring to FIG. 8B, each cathode electrode structure, i.e., each electrode structure 202 of the cathode type, or counter electrode structure 204, is aligned along a longitudinal axis (A CE ) along the length (L CE ) and width (W CE ) and length L CE and width W CE The height (H CE ) and.

[0064] Length of the cathode electrode structure L CEvaries depending on the energy storage device and the intended use of the energy storage device. In general, however, each unit of the cathode group 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. CE By 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 units having a first length and one or more second electrode units having a second length other than the first. In yet another embodiment, the different lengths of the one or more first electrode units and the one or more second electrode units can be selected to accommodate a predetermined shape of the electrode assembly, such as a shape of the electrode assembly having different lengths along one or more of the longitudinal and / or transverse axes, and / or to provide a predetermined performance characteristic of the secondary battery.

[0065] Width W of the cathode electrode structure CE The width W of the cathode electrode structure will vary depending on the energy storage device and the intended use of the energy storage device. In general, however, the cathode electrode structure will typically have 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 units having a first width and one or more second electrode units having a second width other than the first. In yet another embodiment, the different widths of the one or more first electrode units and the one or more second electrode units may be selected to accommodate a predetermined shape of the electrode assembly, such as a shape of the electrode assembly having different widths along one or more of the longitudinal and / or lateral axes, and / or to provide a predetermined performance characteristic of the secondary battery.

[0066] Height H of the cathode electrode structure CE The height H of the cathode electrode structure will vary depending on the energy storage device and the intended use of the energy storage device. In general, however, the cathode electrode structure will typically have 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 CE By 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 building blocks having a first height and one or more second cathode building blocks having a second height other than the first. In yet another embodiment, the different heights of the one or more first cathode building blocks and the one or more second cathode building blocks can be selected to accommodate a predetermined shape of the electrode assembly, such as a shape of the electrode assembly having different heights along one or more of the longitudinal and / or lateral axes, and / or to provide a predetermined performance characteristic of the secondary battery.

[0067] Generally, each cathode electrode structure has a width W CE and the height H of the cathode electrode structure CE Length L, substantially larger than CE For example, in one embodiment, for each cathode electrode, L CE and W CE and H CE and each of the L CE and W CE and L are at least 5:1, respectively. CE and H CE and L are at least 5:1, respectively. CE and W CE and H CE is at least 10:1. By way of further example, in one embodiment, for each cathode electrode structure, L CEand W CE and H CE is at least 15:1. By way of further example, in one embodiment, for each cathode electrode structure, L CE and W CE and H CE Each of the ratios is at least 20:1.

[0068] In one embodiment, the height H of the cathode electrode structure CE and width W CE and H are each at least 0.4:1. For example, in one embodiment, for each cathode electrode structure, CE and W CE and H are each at least 2:1. CE and W CE and H are each at least 10:1. CE and W CE The ratio of H to H is at least 20:1, respectively. However, typically, for each unit of the anode group, CE and W CE The ratio of H to H is generally less than 1,000:1, respectively. For example, in one embodiment, for each cathode electrode structure, CE and W CE and H are at least 500:1, respectively. 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, respectively.

[0069] Returning to FIG. 2, the separator structure 205 separates the electrode structure 202 from the counter electrode structure. The separator structure 205 is made of an electrically insulating but ionically permeable separator material. The separator structure 205 is adapted to electrically isolate each unit of the group of electrode structures 202 from each unit of the group of counter electrode structures 204. Each separator structure 205 typically comprises a microporous separator material that is permeable to a non-aqueous electrolyte, for example, in one embodiment, the microporous separator material comprises pores having a diameter of at least 50 Å, more typically in the range of about 2,500 Å, and a porosity in the range of about 25% to about 75%, more typically in the range of about 35 to 55%.

[0070] Typically, 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. Typically, however, the electrically insulating separator material has a thickness of less than about 12 um, or even less than about 10 um.

[0071] In general, the material of the 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, the separator structure 205 can include a microporous separator material that is permeable to a liquid non-aqueous electrolyte. Alternatively, the separator structure 205 can include a gel electrolyte or solid electrolyte that can conduct carrier ions between the positive and negative electrodes of the unit cells.

[0072] In one embodiment, the separator structure 205 can 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.

[0073] In another embodiment, the separator structure 205 may include an oxide-based electrolyte. An exemplary oxide-based electrolyte is lithium lanthanum titanate (Li 0.34 La 0.56 TiO3), Al-doped lithium lanthanum 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).

[0074] In another embodiment, the separator structure 205 may include a solid electrolyte. An exemplary solid electrolyte is lithium tin sulfide (Li 10 SnP2S 12 ), lithium phosphorus sulfide (β-Li3PS4) and lithium phosphorus sulfide chloride iodide (Li6PS5Cl 0.9 I 0.1 ) and other sulfide-based electrolytes.

[0075] In some embodiments, the separator structure 205 may include a solid lithium-ion conducting ceramic, such as a lithium-containing garnet.

[0076] In one embodiment, the separator structure 205 comprises a microporous separator material that includes a particulate material and a binder and has a porosity (void fraction) of at least about 20% by volume. The pores of the microporous separator material have a diameter of at least 50 Å, typically in the range of about 250-2500 Å. The microporous separator material typically has a porosity of less than about 75%. In one embodiment, the microporous separator material has a porosity (void fraction) of at least about 25% by volume. In one embodiment, the microporous separator material has a porosity of about 35-55%.

[0077] Binders for the microporous separator material may be selected from a wide range of inorganic or polymeric materials. For example, in one embodiment, the binder is an organic material selected from the group consisting of silicates, phosphates, aluminates, aluminosilicates, and hydroxides, such as magnesium hydroxide, calcium hydroxide, etc. For example, in one embodiment, the binder is a fluoropolymer derived from monomers including vinylidene fluoride, hexafluoropropylene, and tetrafluoropropene, etc. 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 methyl cellulose, carboxymethyl cellulose, styrene rubber, butadiene rubber, styrene butadiene rubber, isoprene rubber, polyacrylamide, polyvinyl ether, polyacrylic acid, polymethacrylic acid, and polyethylene oxide. In another embodiment, the binder is selected from the group consisting of acrylates, styrenes, epoxies, and silicones. In another embodiment, the binder is a copolymer or blend of two or more of the foregoing polymers.

[0078] The particulate material comprised by the microporous separator material may also be selected from a wide range of materials. Generally, such materials have relatively low electronic and ionic conductivity 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 molecular weight of 1×10 -4 By way of further example, in one embodiment, the particulate material has a conductivity for carrier ions (e.g., lithium) of less than 1×10 -5 By way of further example, in one embodiment, the particulate material has a conductivity for carrier ions of less than 1×10 -6 The particulate material has a conductivity for carrier ions of less than 10 ... In an embodiment, the particulate material has an average particle size of about 20 nm to 2 micrometers, more typically 200 nm to 1.5 micrometers, hi one embodiment, the particulate material has an average particle size of about 500 nm to 1 micrometer.

[0079] In alternative embodiments, the particulate materials comprised by the microporous separator material may be bound together by techniques such as, for example, sintering, bonding, curing, etc., while maintaining a desired void fraction for electrolyte ingress to provide ionic conductivity for the function of the battery.

[0080] In an assembled battery, the microporous separator material of separator structure 205 is permeable to a non-aqueous electrolyte suitable for use as a secondary battery electrolyte. Typically, the non-aqueous electrolyte comprises 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 LiClO4, LiBF4, LiPF6, LiAsF6, LiCl, and LiBr, as well as inorganic lithium salts such as LiB(CH5)4, LiN(SO2CF3)2, LiN(SO2CF3)3, LiNSO2CF3, LiNSO2CF5, LiNSO2C4F9, LiNSO2C5F 11 , LiNSO2C6F 13 , and LiNSO2C7F 15 Exemplary organic solvents for dissolving lithium salts include cyclic esters, chain esters, cyclic ethers, and chain ethers. Specific examples of cyclic esters include propylene 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 propionates, dialkyl malonates, and alkyl acetates. 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.

[0081] In one embodiment, the microporous separator of the separator structure can be permeable to 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.

[0082] The electrode bus bar 208 is a cathode electrode bus bar when the electrode structure 202 is of a cathode type and is an anode electrode bus bar when the electrode structure 202 is of an anode type. Similarly, the counter electrode bus bar is a cathode electrode bus bar when the counter electrode structure 204 is of a cathode type and is an anode electrode bus bar when the counter electrode structure 204 is of an anode type. In an exemplary embodiment, 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 may be any suitable conductive material to enable the electrode assembly 200 to function as described herein.

[0083] 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 adhesively affixed to the counter electrode bus bar 210 without any components electrically or physically located between them. 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 current collector 218.

[0084] 3A and 3B illustrate an exemplary 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 that is sized and shaped to receive the counter electrode bus bar 210. A portion 302 of the counter electrode current collector 218 extends beyond the slot 300. The counter electrode bus bar 210 is inserted through the slot 300, and the portion 302 of the counter electrode current collector 218 is bent to contact the counter electrode bus bar 210, as shown in FIG. 3B. The portion 302 of the counter electrode current collector 218 in contact with the counter electrode bus bar 210 is then welded to the counter electrode bus bar 210.

[0085] 17 illustrates another exemplary 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 a 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 on 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.

[0086] Returning to FIG. 2 , each constituent element of the group of current limiters 206 is electrically connected between a different electrode current collector 214 and an electrode bus bar 208. The current limiters 206 are configured to limit the current that can flow through the electrode current collectors 214 and, correspondingly, through the electrode structure 202 to which the electrode current collectors are connected. Thus, for example, if 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 the 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 in which there is an electrical short circuit between the electrode and the counter electrode of the unit cell, to a current through a constituent element of the unit cell group (herein referred to as I ) that would induce thermal runaway of the constituent element of the unit cell group. tr or I L The current limiter limits I to a value I less than the current limit (sometimes referred to as current limit). The current limiter provides a soft landing for the battery in the event of a short circuit. The current limiter continuously allows a non-zero level of current to flow in the event of a short circuit, but limits the current to below a level that would cause thermal runaway. This current continues to flow until the battery is discharged and the risk of thermal runaway ends.

[0087] The current limiter 206 is a resistive current limiter. The current limiter 206 has a non-zero resistance within the range of the normal operating temperature of the 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 temperature. The resistance is such that the current limiter 206 limits the current that may pass through any unit cell and prevents the current from reaching a level that may cause catastrophic failure, or other maximum current level determined for other performance or abuse tolerance reasons determined during battery design. The current limiter 206 does not rely on the fusing characteristics of a resistive material or any PTC characteristics. That is, although the current limiter 206 may exhibit a PTC, a PTC is not required for the current limiter 206 to function as described herein. Rather, the resistance of the current limiter 206 over the range of normal operating temperatures of the electrode assembly 200 is sufficient to limit the current. In some embodiments, the resistance may increase or decrease over the range of normal operating temperatures (i.e., the current limiter may have a negative temperature coefficient). Each current limiter 206 is electrically in series with the electrode current collector 214 to which the current limiter 206 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 the current limiter 206 attached to the associated electrode structure 202. Adding resistance to a battery is traditionally not recommended because it increases the losses the battery experiences as current flows into (during charging) and out of (during 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 in the present disclosure is selected to be small enough to have a limited voltage drop across the current limiter 206, and therefore a limited power loss.In an exemplary embodiment, the resistance of the current limiters is selected to have no more than 20 mV drop across each of the current limiters 206 during charging or discharging at a 1 C rate to limit losses during normal operation while continuing to protect the battery during a short circuit.

[0088] In the exemplary embodiment, each individual unit cell, 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 layered battery), a relatively low capacity, and an internal resistance high enough that even if there is a short circuit between the electrode structure 202 and the counter electrode structure 204 of the unit cell, the current through the isolated unit cell cannot reach a level sufficient to cause thermal runaway and catastrophic failure. However, in an electrode assembly such as the electrode assembly 200, when multiple unit cells are connected in parallel to a bus bar such as the bus bar 208, all of the unit cells will provide current to the unit cell that has an internal short circuit. In such a situation, without the current limiter 206, sufficient current may pass through the shorted unit cell to cause thermal runaway and catastrophic failure of the electrode assembly 200 and the battery that includes the electrode assembly 200. 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 reduction in the maximum current according to Ohm's law.

[0089] More specifically, the capacity of the electrode assembly 200 is subdivided into a number (n) of electrode unit cells, each of which includes 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 bl Each individual unit cell has a forced internal short circuit (FISC) resistance (R s ) through a short circuit

number

number

[0090] 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 will detect the FISC of the affected (i.e., shorted) individual unit cell.

number

number

[0091] Each of the current limiters 206 has a non-zero resistance (R cld ) results in the FISC power of the shorted unit cell being given by:

number

[0092] The resistance R of each current limiter 206 cld is for the shorted unit cell

number

number

[0093] The required resistance of the current limiter 206 may also be considered in terms of the resistance required to limit the current through a shorted unit cell below a threshold current that is sufficient to cause thermal runaway. Therefore, 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. The threshold current required to cause thermal runaway may vary somewhat depending on the construction of the electrode assembly and the capacity of the individual unit cells, but for similarly constructed electrode assemblies, the threshold current remains relatively constant. In an exemplary embodiment, the threshold current is about 8 amps. In other embodiments, the threshold current may be about 4 amps, about 8 amps, about 10 amps, about 12 amps, or between 8 amps and 12 amps. The resistance required for the current limiter 206 will vary depending on the particular configuration of the battery and battery components. For a similar electrode assembly, the resistance required to limit the current below a threshold current generally increases as the capacitance of the individual unit cells increases.

[0094] More specifically, the capacity of a traditional stacked battery cell is subdivided into the number (N) of electrode unit cells for which each positive and negative electrode forms a voltage (V). The number of unit cells in a complete stack is represented by a capital N, while the number of unit cells as a variable is represented by a lower case n, for example when performing repetitive assays with different numbers of unit cells. Each individual electrode unit cell has its own characteristic resistance (R bl Each individual unit cell has a forced internal short circuit (FISC) resistance (R s ) through the current (I bl ) can be discharged. The FISC current of an individual unit cell is given by

number

[0095] The positive and negative electrodes of each unit cell have their own characteristic resistance (R t ), all the unit cells of the cell will discharge current (I cell ) The FISC current of all unit cells of a parallel connected cell is given by:

number

[0096] In at least some cases, the characteristic resistance of an individual unit cell is determined by the thermal runaway current (I), which is the current that a unit cell can discharge through the FISC that may be sufficient to cause self-accelerating exothermic decomposition and thermal runaway. tr ) is low enough to exceed the thermal runaway current (I tr ) and is increasingly likely to result in catastrophic failure of the cell.

[0097] 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

[0098] Other embodiments may use impedance at any other frequency, or DC resistance. In some embodiments, the actual short circuit resistance of a shorted unit cell is calculated and the worst case internal short circuit resistance R s,WCFISC In place of R in equation (6), as used herein, the short-circuit resistance R s is the actual measured short circuit resistance of the unit cell, or the worst case internal short circuit resistance R, unless otherwise specified. s,WCFISC An exemplary method for determining the actual short circuit resistance is provided below.

[0099] The resistance of an individual unit cell is determined by its impedance at full charge, further taking into account the number of unit cell subdivisions and the resistance of the terminals calculated based on the material composition and geometry of the unit cell subdivisions. For an example using 20 kHz impedance, the resistance of the unit cell is given by:

number

[0100] In an exemplary embodiment, the thermal runaway current (I tr ) is determined by performing a worst-case forced internal short circuit assay described below. In another embodiment, the thermal runaway current (I tr ) may be estimated, derived from simulations, determined using different assays, or arrived at by any other suitable method. However determined, the thermal runaway current (I tr ) in equation (6) to determine the current limiter (R cld ) to determine the required resistance. cldBy choosing to provide a thermal runaway current (I tr )

[0101] In an exemplary embodiment, the resistance of each current limiter 206 at 25 degrees Celsius (°C) is approximately 0.25 ohms (Ω), limiting the 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 1C 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 simultaneously limiting losses during normal operation of the battery. The exact values ​​within the range, and which range to select, may 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 resistance that produces a voltage drop of less than 0.5 volts when the electrode assembly 200 (or individual unit cell) is being charged or discharged at a 1C rate when discharged from a maximum of charge (TOC) condition, i.e., the current at a 1C rate multiplied by the resistance of the current limiter 206 is less than 0.5 volts to minimize losses during normal operation while keeping the current adequately limited during a short circuit.

[0102] The current limiter 206, in an exemplary embodiment, is positioned on the electrode bus bar 208. The current limiter is physically located between the electrode current collector 214 and the electrode bus bar 208. In other embodiments, the current limiter 206 is electrically between the electrode current collector 214 and the electrode bus bar 208, but physically outside of the connection between the electrode current collector 214 and the electrode bus bar 208.

[0103] 4A and 4B, an exemplary current limiter 206 is comprised of a single layer 400 of conductive adhesive disposed on a surface 402 of an electrode bus bar 208 to which an electrode current collector 214 is welded. The electrode current collector 214 includes slots 404 (FIG. 4B) and portions 406 that are similarly used to connect the electrode current collector 214 to the electrode bus bar 108, similar to the slots 300 and portions 302 of the counter electrode current collector 218 shown in FIGS. 3A and 3B. Each individual current limiter 206 is bent over the electrode bus bar 208 and portions 408 of the single layer 400 located between the portions 406 of the current collector that are welded to the electrode bus bar 208. In other embodiments, the conductive adhesive is applied onto 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, the conductive adhesive is applied to the electrode bus bar 208 around the location of the portion 406 where the electrode current collector will be located when the portion 406 is bent over the electrode bus bar. Each application of the conductive adhesive, and therefore each current limiter 206, is physically separated from each other application of the 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 located around the location of the portion 406 in FIG. 4B and each current limiter 206 is physically separated 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 over the end of the current collector without the use of slots, etc.), and the conductive adhesive is located between the current collector and the bus bar.

[0104] 18 illustrates another exemplary embodiment in which the exemplary 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 a surface 1800 of the electrode bus bar 208 to which the electrode current collector 214 is 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 does not have to be bent at an exact 90 degree angle, and can 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 an exemplary 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 apply pressure to the bus bar to bond the electrode bus bar 208 to the portion 1802 using the conductive adhesive. Although illustrated against the conductive adhesive, it should be understood that the portion 1802 of the current collector may extend into the conductive adhesive. Each individual current limiter 206 is a portion 1804 of a single layer 1801 that is bent over the electrode bus bar 208 and located between the portions 1802 of the current collector attached to the electrode bus bar 208. In other embodiments, as shown for example in FIG. 19, the conductive adhesive is applied to the electrode bus bar 208 in individual portions 1900, one for each electrode current collector 214 that is 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 portion 1802 that the electrode current collector will be positioned over when the portion 1802 is bent over the electrode bus bar. Each application of the conductive adhesive, and therefore each current limiter 206, is physically isolated from each other application of the 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 portion 1802 and each current limiter 206 is physically isolated from the other current limiters 206.

[0105] In yet 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, or may be applied in individual sections to the electrode bus bar, or may be applied 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 the conductive adhesive. Furthermore, in some embodiments, a discrete resistor may be electrically connected between the electrode current collector 214 and the electrode bus bar 208. The discrete resistor may be physically located between the electrode current collector 214 and the electrode bus bar 208, or may be outside the interface between the electrode current collector 214 and the electrode bus bar 208, but may be electrically between the electrode current collector 214 and the electrode bus bar 208. The discrete resistor may be any suitable resistor, including a wirewound resistor, a thick film resistor, a thin film resistor, a carbon film resistor, a carbon pile resistor, a metal film resistor, a foil resistor, or the like.

[0106] In some embodiments, one or more interfacial layers are included between the current limiter 206 and the electrode busbar 208 or between the current limiter 206 and the electrode current collector 214. In general, the resistance between the electrode busbar 208 and each electrode current collector 214 is defined by the resistance of the current limiter 206 plus the resistance of the interface between the current limiter 206 and the electrode current collector 214 plus the resistance of the interface between the current limiter 206 and the electrode busbar 208. In general, the interfacial resistance may be generated by an imperfect (e.g., "real" connection rather than "ideal") electrical connection between the current limiter 206 and the electrode busbar 208 and electrode current collector 214. Without being limited to any particular theory, the imperfect electrical connection may be caused, for example, by microscopic structural variations in the surface of the electrode busbar 208 and / or the electrode current collector 214, the distribution and structure of conductive particles in the current limiter 206, and the like. 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, the electrode bus bar 208 is provided with an interface layer 1400. In Figure 15, the electrode current collector 214 is provided with an interface layer 1500. The interface layer 1500 may be provided on each current collector 214 or on less than all current collectors 214. In Figure 16, the electrode bus bar 208 is provided with an interface layer 1400 and the electrode current collector 214 is provided with an interface layer 1500.

[0107] In some embodiments, the interfacial layers 1400 and 1500 are carbon-based coatings. For example, the interfacial layers 1400 and / or 1500 can be coatings produced by slurry coating carbon nanotubes onto the electrode bus bar 208 and / or electrode current collector 214. In other embodiments, the interfacial layers are graphite coatings or any other suitable conductive coatings. In some embodiments, the interfacial layers 1400 and / or 1500 are applied using a hot anvil technique in which heat is applied to the electrode bus bar 208 and / or electrode current collector 214 to coat the electrode bus bar 208 and / or electrode current collector 214 with a selected material to form the interfacial layers 1400 and / or 1500.

[0108] The conductive adhesive used in the current limiter 206 in the exemplary embodiment is an adhesive polymer, adhesive copolymer, or blend with a conductive material suspended therein. In an exemplary 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 in the adhesive polymer. In general, a desired polymer is any that (a) is stable in the environment of a Li-ion battery cell (i.e., does not dissolve in the electrolyte, does not react with the electrolyte components or any other battery components, or does not undergo redox chemistry or reactions that degrade the material during operation of the cell), and (b) has a melting point higher than the typical operating temperature of a Li-ion battery. Since adhesion is an important property of the 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. Thus, a material or blend of materials that has some elasticity, particularly a glass transition temperature (Tg) higher than 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 of rupture and / or elongation at break). In some embodiments, the adhesive polymer is a flowable adhesive polymer. In such embodiments, the conductive adhesive should have flow properties that allow melt processing, including incorporation of conductive aids and other additives, film / sheet preparation by standard methods such as cast film, blown film, and calendaring, if desired. 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 (min), preferably 0.1 to 100 g / 10 min, and most preferably 0.5 to 20 g / 10 min. The melting point of the polymer used in the conductive adhesive should allow melt processing and melt bonding to the cell via melt pressing or related techniques and should be above the typical operating temperature range of the cell. Polymers that melt at 40°C to 300°C may be used for the conductive adhesive.Polymers having a melting point in the range of 60°C to 200°C are preferred, and polymers having a melting point in the range of 70°C to 165°C are most preferred.

[0109] Exemplary 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 of polyethylene (such as ethylene / 1-octene, ethylene / 1-hexene, ethylene / 1-butene, and ethylene / propylene copolymers), polypropylene and copolymers of polypropylene, functionalized or derivatized polyethylene or polypropylene (such as maleic anhydride grafted materials), and the like.

[0110] 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. Materials that impart the desired conductivity at lower loadings are most desirable, since high loadings of additives can undesirably alter the properties of the polymer blend. 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 costs of manufacture.

[0111] The conductive material may be metal powder or fiber, conductive carbon black, metal-coated carbon fiber, and carbon nanotubes, or blends 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. The preferred conductive material for use in the conductive adhesive is metal-coated carbon fiber and conductive carbon black, or blends thereof. The metal-coated carbon fiber may be coated with any other metal coating, including nickel, copper, gold, silver, tin, titanium, molybdenum, platinum chromium, aluminum, or alloys. In the most preferred example, the conductive material includes nickel-coated carbon fiber 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).

[0112] For embodiments in which the conductive material is a fiber (such as 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 exemplary 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 of the conductive material are from 10:1 to 10,000:1, preferably from 50:1 to 5000:1, and most preferably from 100:1 to 2000:1.

[0113] The loading of conductive material in 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 from 2% to 40%, and most preferably, the loading is from 3% to 30%.

[0114] The resistivity of the conductive adhesive is 5.0 x 10-7 and 5.0 x 10 3 Ω cm, preferably 5.0×10 -5 and 5.0 x 10 1 Ω cm, most preferably 5.0×10 -3 and 5.0 x 10 -1 The resistivity should be in the range of Ω·cm. Polymer resistivity is measured by preparing a sheet or film of the polymer blend with conductive additives and then laminating the sheet or film to a copper test structure consisting of four rectangular bars bonded adjacent to each other in an array with a defined spacing. Lamination may be accomplished using methods such as hot pressing or heated calenders. Once lamination is complete, resistivity measurements are accomplished using a typical four-point needle method, where a source needle applies a current through the sheet-like film by contacting the two outermost bars, and a sense needle 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.

[0115] In an exemplary 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 about 0.01-1.0 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 the adhesive polymer more conductive) and adding less carbon black increases the resistivity (i.e., makes the adhesive polymer less conductive). In an exemplary embodiment, carbon black is added to the adhesive polymer in an amount of 5%-30% by weight to achieve the desired resistivity. The conductive adhesive so prepared is applied to the electrode busbar 208 at a thickness between 20 microns and 200 microns thick. By adjusting the resistivity of the adhesive polymer and the thickness of application, the desired resistance of the current limiter 206 can be achieved.

[0116] FIG. 5 is a simplified diagram of another exemplary electrode assembly 500 for cycling between charged and discharged states of a battery. The electrode assembly 500 is similar to the electrode assembly 200, and the same reference numbers are used to identify common components. For clarity of illustration, the separator structure 205 is not shown in FIG. 5, but is included in this exemplary electrode assembly 500. Unlike the electrode assembly 200, the electrode assembly 500 includes a group 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 busbars 210. In some embodiments, the additional current limiters 502 are the same as the current limiters 206 discussed above, and the connections are made in the same manner as the current limiters 206. However, in some embodiments, the additional current limiters 502 have a different composition and / or are different from the current limiters 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 conductive material suspended in a conductive adhesive that is different from 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 that is less than the resistance 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 would lead to a catastrophic failure.

[0117] 6 is a simplified diagram of another exemplary electrode assembly 600 for cycling between charge and discharge states of a battery. The electrode assembly 600 is similar to the electrode assembly 200, and the same reference numbers are used to identify common components. For clarity of illustration, some details of the electrode structure 202 and the counter electrode structure 204 are omitted, but all aspects of the electrode structure 202 and the counter electrode structure 204 discussed above are the same in the electrode assembly 600. Unlike the electrode assembly 200, the electrode assembly 600 includes a group of additional electrode structures 602 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.

[0118] 7 is a simplified diagram of another exemplary electrode assembly 700 for cycling between charge and discharge states of a battery. The electrode assembly 700 is similar to the electrode assembly 500, and the same reference numbers are used to identify common components. For clarity of illustration, some details of the electrode structure 202 and the counter electrode structure 204 are omitted, but all aspects of the electrode structure 202 and the counter electrode structure 204 discussed above are the same in the electrode assembly 700. Unlike the electrode assembly 500, the electrode assembly 500 includes a group of additional electrode structures 602 and a group of additional counter electrode structures 704 all directly connected to the electrode bus bar 208. That is, the additional electrode structures 602 and the additional counter electrode structures 704 are connected to the electrode bus bar 208 without the current limiter 206 or the additional current limiter 502.

[0119] FIG. 9 is an exemplary 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 electrodes, counter electrodes, additional electrodes, and additional counter electrode structures 202, 204, 602, 704 are referred to as "electrode subunits" in the following paragraphs. A predetermined number of electrode subunits are stacked with a separator 205 in a stacking direction (e.g., widthwise in FIG. 2) to form a multi-unit electrode stack. Typically, 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 in the multi-unit electrode stack any suitable number of electrode structures 202 and at least 10 counter electrode structures 204. The multi-unit electrode stack is then placed in a pressure constraint having a pressure plate that applies pressure to the multi-unit electrode stack to bond all of the electrode subunits together.

[0120] In a multi-unit electrode stack, the electrode and counter electrode structures extend in a longitudinal direction (e.g., lengthwise in FIG. 2) perpendicular to the stacking direction. An end portion of the electrode current collector (e.g., the portion of the electrode current collector 214 that extends above the remainder of the electrode structure 202 in FIGS. 4B, 14, 15, 16, 18, and 19) extends longitudinally beyond the electrode active material and separator structure. The end portion that extends above the electrode active material and separator structure is bent approximately perpendicular to the longitudinal direction of the electrode structure to extend in or against the stacking direction, as shown in FIGS. 4B, 14, 15, 16, 18, and 19. In embodiments without a slot (e.g., FIGS. 18 and 19), the end portion is bent before contacting a surface of the electrode bus bar with the end portion of the electrode current collector (i.e., the bent end portion) to position the electrode bus bar extending in the stacking direction. In an exemplary embodiment, a conductive adhesive layer (e.g., a conductive adhesive that functions as a current limiting device as discussed herein) is located between a surface of the electrode bus bar and an end portion of the electrode current collector. In some embodiments, the conductive adhesive layer is disposed on a surface of the electrode bus bar that is in contact with 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 via 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.

[0121] In embodiments using slots in the current collectors (e.g., FIG. 4B and FIGS. 14-16), the busbars are inserted through the slots prior to bending the current collectors. In such embodiments, the electrode busbar 208 and counter electrode busbar 210 are placed through slots 404, 300 (shown in FIGS. 3A-4B) in the respective current collectors 214, 218 with the current limiters 206 (and 502, if applicable) between the busbars 208, 210 and the current collectors 214, 218. Once the busbars 208, 210 are placed through the slots 404, 300, the portions 406, 302 are folded back towards the respective busbars 208, 210. The electrode busbar 208 is welded to portion 406 of the electrode current collector 214 and the counter electrode busbar 210 is welded to portion 302 of the counter electrode current collector 218. The welding may be done using a laser welder, friction welding, ultrasonic welding, or any suitable welding method for welding the bus bars 208 and 210 to the current collectors 214, 218. After welding the bus bars to the multi-unit electrode stack, the laminated cell 900 is completed and may be placed into a battery formed pouch, metal can, or other suitable container. In other embodiments, any other suitable method of connecting the electrode bus bars 208 and counter electrode bus bars 210 to the current collectors may be used, including methods such as those without slots and where the bus bars are attached over tabs on the current collectors.

[0122] Figure 10 is a top view (i.e., as viewed in 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.

[0123] 11A and 11B, after the formation of the stacked cells 900, the stacked cells 900 proceed to a packaging station 1100, where the stacked cells 900 are coated with an insulating packaging material 1101, such as a multi-layer aluminum polymer material, plastic, and the like, to form a battery package 1102. In one embodiment, the battery package 1102 is evacuated using a vacuum and filled with an electrolyte material through an opening (not shown). The insulating packaging material can be sealed around the stacked cells 900 using heat sealing, laser welding, adhesives, or any suitable sealing method. After sealing, the battery insulating packing material forms a sealed housing. The ends of the bus bars 208 and 210 remain exposed and are not covered by the battery package 1102, and the exposed ends serve as the external electrode terminals and counter electrode terminals of the sealed battery housing. 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 electrode 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 electrode 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.

[0124] 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 of the unit cell. The FISC assay is an iterative test. The test is performed on an electrode assembly containing n unit cells (n is a positive integer). Each unit cell contains a single electrode structure 202 adjacent to a single counter electrode 204, has a separator 205 therebetween, and contains a current limiter 206. The first iteration is performed with the electrode assembly electrically disconnected from any other electrode structures 202, 204 when n=1 (i.e., there is a single unit cell). 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 area 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 at a speed of 1.0 mm / s onto the unit cell 1200 where the embedded conductive particles are located. This causes the conductive particles 1202 to short and electrically connect the electrode structure 202 and the counter electrode structure 204. 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 experiences 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 to have a thermal runaway current (I tr ) for this configuration of unit cell 1200, different tests, estimates, simulations, etc. may 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 failed unit cell may not be a good candidate for use in the current limiters described herein, since the resistance required for the current limiter to adequately limit the current is likely high enough to result in undesirable energy losses under normal charging and discharging.

[0125] If the unit cell 1200 does not experience a catastrophic failure, the configuration of the unit cell 1200 passes the first iteration, n is incremented by 1, and a new assembly containing two unit cells (i.e., n=2) is assembled, one of the unit cells is configured with conductive particles 1202 as discussed above for the first step. The FISC test is repeated on 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, one of the unit cells including conductive particles, and the FISC test is performed again. The worst case forced internal short circuit resistance at each step is given by: R s、WCFISC (n)=R 20kHz(Vtoc,n) (9)

[0126] 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 has a current value of n-1 unit cells) is used to calculate the thermal runaway current (I tr ) is determined. Thermal runaway current (I tr ) is given by:

number

[0127] Then, the thermal runaway current (Itr ) may be used in inequality (6) to determine the resistance required for each current limiter 206 and to create an electrode assembly including current limiters 206 each having the determined resistance.

[0128] Although discussed above 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, then testing may begin at n=3 with an electrode assembly containing three unit cells.

[0129] R in Equation (6) s The actual short circuit resistance for use as may 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 electrolyte are subjected to FISC using the assembly and technique 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 with a separator 205) has conductive particles 1202 positioned in the area 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 crushes the unit cell, causing the conductive particles 1202 to short and electrically connect the electrode structure 202 and the counter electrode structure 204. The actual short circuit resistance of the shorted unit cell may then be measured and used in equation (6).

[0130] FIG. 13 is a simplified diagram of a portion of another electrode assembly 1300 for cycling between charged and discharged states in a battery. The electrode assembly 1300 includes similar components as the electrode assemblies described above, and these components are the same unless otherwise specified. The group of counter electrode structures, the group of separator structures, and the counter electrode busbar are omitted from the figure for clarity. The group of current limiters 206 in the electrode assembly 1300 has fewer units than the group of electrode structures 202. The group of electrode structures is divided into groups 1302 of electrode structures 202. Each group 1302 of electrode structures 202 includes two electrode structures 202 in FIG. 13. In other embodiments, the group 1302 may include any number of electrode structures 202, so long as the group includes more than one electrode structure 202. Each electrode structure 202 in the group 1302 is electrically connected in parallel to the other electrode structures 202 in the 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 include an arrangement of similar grouped counter electrode structures 204 that additionally or alternatively share a single current limiter 206. Further, 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.

[0131] The resistance of the current limiter 206 in the electrode assembly 1300 is determined by modifying inequality (6) discussed above. Specifically, the resistance of the shared current limiter 206 in the electrode assembly 1300 is determined to satisfy:

number

[0132] 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 the normal operating temperature range. The exact value of the ratio R2 / R1 may vary depending on the capacity and / or voltage of the battery. In exemplary embodiments, R2 / R1 is approximately equal to 0.5, 0.95, or 0.0275. In some embodiments, R2 / R1 may be greater than 0.1, greater than 0.5, greater than 0.95, or greater than 0.1.

[0133] The following embodiments are provided to illustrate aspects of the disclosure, but these embodiments are not intended to be limiting, and other aspects and / or embodiments may be provided.

[0134] EMBODIMENT 1 An electrode assembly for cycling between a charged state and a discharged state, the electrode assembly comprising a group of electrode structures, a group of counter electrode structures, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. Each constituent unit of the electrode structure group comprises an electrode active material and an electrode current collector, the electrode current collector being constituted by a constituent unit of the electrode structure group and electrically connected in parallel to the electrode bus bar. Each constituent unit of the counter electrode structure group comprises a counter electrode active material and a counter electrode current collector, the counter electrode current collector being constituted by a constituent unit of the counter electrode structure group and electrically connected in parallel to the counter electrode bus bar. The group of current limiters includes at least 10 current limiters. Each of the electrode current collectors is electrically connected to the electrode bus bar by a constituent unit of the group of current limiters, and at a temperature of 25 degrees Celsius (°C), each constituent unit of the group of current limiters has a resistance of 0.25 ohms (Ω) or more.

[0135] EMBODIMENT 2 An electrode assembly for cycling between charged and discharged states includes a group of electrode structures, each unit of the group of electrode structures comprising an active electrode material and an electrode current collector, an electrode busbar, the electrode current collector of each unit of the group of electrode structures being electrically connected in parallel to the electrode busbar, a group of counter electrode structures, each unit of the group of counter electrode structures comprising an active counter electrode material and a counter electrode current collector, a counter electrode busbar, the counter electrode current collector of each unit of the group of counter electrode structures being electrically connected in parallel to the counter electrode busbar, and a group of current limiters, each unit of the group of current limiters electrically connecting the electrode current collector of each unit of the group of electrode structures to the electrode busbar, and each unit of the group of current limiters having a resistance of 0.25 ohms (Ω) or greater at a temperature of 25 degrees Celsius (°C).

[0136] EMBODIMENT 3 The electrode assembly for cycling between a charged state and a discharged state includes a group of electrode structures, a group of counter electrode structures, a group of separator structures for electrically isolating the group of electrode structures from the group of counter electrode structures, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. Each constituent unit of the electrode structure group comprises an electrode active material and an electrode current collector, the electrode current collector being constituted by a constituent unit of the electrode structure group and electrically connected in parallel to the electrode bus bar. Each constituent unit of the counter electrode structure group comprises a counter electrode active material and a counter electrode current collector, the counter electrode current collector being constituted by a constituent unit of the counter electrode structure group and electrically connected in parallel to the counter electrode bus bar. Each constituent unit of the current limiter group is electrically connected between a different electrode current collector and the electrode bus bar, and at a temperature of 25 degrees Celsius (°C), each constituent unit of the current limiter group has a resistance greater than 0.25 ohms (Ω).

[0137] EMBODIMENT 4 The electrode assembly for cycling between a charged state and a discharged state includes a group of electrode structures, a group of counter electrode structures, a group of separator structures for electrically isolating the group of electrode structures from the group of counter electrode structures, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. Each constituent unit of the electrode structure group comprises an electrode active material and an electrode current collector, the electrode current collector being constituted by a constituent unit of the electrode structure group and electrically connected in parallel to the electrode bus bar. Each constituent unit of the counter electrode structure group comprises a counter electrode active material and a counter electrode current collector, the counter electrode current collector being constituted by a constituent unit of the counter electrode structure group and electrically connected in parallel to the counter electrode bus bar. Each constituent unit of the current limiter group is positioned between a different electrode current collector and the electrode bus bar and is electrically connected to the constituent unit's associated electrode current collector and electrode bus bar, and at a temperature of 25 degrees Celsius (°C), each constituent unit of the current limiter group has a resistance greater than 0.25 ohms (Ω).

[0138] EMBODIMENT 5 The electrode assembly for cycling between charged and discharged states includes a group of electrode structures, a group of counter electrode structures, a group of separator structures for electrically isolating the group of electrode structures and the group of counter electrode structures, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. The electrode assembly has a fully charged capacity C at 25 C, a current threshold I that may cause failure of the electrode assembly. Th and a voltage difference V exists between the constituent units of the electrode structure group and the constituent units of the counter electrode structure group. The constituent units of the electrode structure group each have an electrode structure resistance and include an electrode active material and an electrode current collector, the electrode current collector being constituted by the constituent units of the electrode structure group and electrically connected in parallel to the electrode bus bar. Each constituent unit of the counter electrode structure group includes a counter electrode active material and a counter electrode current collector, the counter electrode current collector being constituted by the constituent units of the counter electrode structure group and electrically connected in parallel to the counter electrode bus bar. Each constituent unit of the current limiter group is electrically connected between a different electrode current collector and the electrode bus bar, and at a temperature of 25 degrees Celsius (°C), each constituent unit of the current limiter group limits the current passing through the constituent unit of the electrode structure group associated with the constituent unit to I.Th less than V, the resistance being determined as a function of V, the electrode structure resistance of the constituent unit of the associated electrode structure group, the resistance of a short circuit between the constituent unit of the associated electrode structure group and a constituent unit of the counter electrode structure group, and the number of constituent units of the electrode structure group connected to the electrode bus bar.

[0139] EMBODIMENT 6 I Th 6. The electrode assembly of embodiment 5, wherein the current draw is greater than or equal to 8 amps and less than or equal to 12 amps.

[0140] EMBODIMENT 7 I Th 7. The electrode assembly of embodiment 5 or embodiment 6, wherein the current draw is 8.0 amps.

[0141] EMBODIMENT 8 8. The electrode assembly of any one of embodiments 5 to 7, wherein V is 4.35 volts.

[0142] EMBODIMENT 9 An electrode assembly for cycling between a charged state and a discharged state includes a group of electrode structures, a group of counter electrode structures, a group of separator structures for electrically isolating the group of electrode structures and the group of counter electrode structures, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. The electrode assembly has a fully charged capacity C at 25 degrees Celsius (°C). Each constituent unit of the electrode structure group includes an electrode active material and an electrode current collector, the electrode current collector being constituted by a constituent unit of the electrode structure group and electrically connected in parallel to the electrode bus bar. Each constituent unit of the counter electrode structure group includes a counter electrode active material and a counter electrode current collector, the counter electrode current collector being constituted by a constituent unit of the counter electrode structure group and electrically connected in parallel to the counter electrode bus bar. The group of current limiters is located at the electrical connection between the electrode busbar and each electrode current collector of the electrode group constituent elements, such that at a temperature of 25°C, (i) each constituent element of the current limiter group includes a resistor that limits the amount of current that can flow between the electrode busbar and each constituent element of the constituent element's associated electrode current collector to a maximum of 8 amperes, and (ii) when current is passed between the electrode busbar and each constituent element of the electrode current collector subset to charge or discharge the electrode assembly at a C-rate of 1C, the voltage drop through each constituent element of the current limiter group does not exceed 20mV.

[0143] Embodiment 9.1 An electrode assembly for cycling between charged and discharged states within a normal operating temperature range of minus 30 degrees Celsius (°C) to 80°C, the electrode assembly comprising a group of unit cells, an electrode busbar, a counter electrode busbar, and a group of current limiters. Each constituent unit of the unit cell group has a cell resistance R1 and comprises an electrode structure, a separator structure, and a counter electrode structure, the electrode structure of each constituent unit of the unit cell group comprises an electrode current collector and an electrode active material layer, and the counter electrode structure of each constituent unit of the unit cell group comprises a counter electrode current collector and a counter electrode active material layer. For each constituent unit of the unit cell group, (a) the electrode current collector of the electrode structure is electrically connected to the electrode busbar, (b) the counter electrode current collector of the counter electrode structure is electrically connected to the counter electrode busbar, and (c) the constituent unit of the current limiter group is electrically connected (i) between the electrode current collector and the electrode busbar, or (ii) between the counter electrode current collector and the counter electrode busbar. Each element of the current limiter group has a resistance R2 such that R2 / R1>0.01 when the electrode assembly is within the normal operating temperature range.

[0144] Embodiment 9.2 An electrode assembly for cycling between charged and discharged states within a normal operating temperature range of minus 20 degrees Celsius (°C) to 80°C, the electrode assembly comprising a group of unit cells, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. Each constituent unit of the unit cell group comprises an electrode structure, a separator structure, and a counter electrode structure, the electrode structure of each constituent unit of the unit cell group comprises an electrode current collector and an electrode active material layer, and the counter electrode structure of each constituent unit of the unit cell group comprises a counter electrode current collector and a counter electrode active material layer. For each constituent unit of the unit cell group, (a) the electrode current collector of the electrode structure is electrically connected to the electrode bus bar, (b) the counter electrode current collector of the counter electrode structure is electrically connected to the counter electrode bus bar, and (c) at least one constituent unit of the current limiter group is electrically connected (i) between the electrode current collector and the electrode bus bar, or (ii) between the counter electrode current collector and the counter electrode bus bar. For each unit cell, at least one member of the current limiter group has sufficient resistance to substantially continuously limit the current through the unit cell to a non-zero current below a threshold current I, which is below a current that would induce thermal runaway of the unit cell, when the electrode assembly is within a normal operating temperature range, until the electrode assembly is discharged.

[0145] EMBODIMENT 10 The electrode assembly according to any one of embodiments 5 to 9.2, wherein the resistance of each constituent unit of the current limiter group at a temperature of 25 degrees Celsius (° C.) is greater than 0.25 ohms (Ω).

[0146] EMBODIMENT 11 11. The electrode assembly according to any one of embodiments 3 to 10, wherein the resistance of each constituent unit of the current limiter group does not increase at a temperature higher than 25°C.

[0147] EMBODIMENT 12 12. The electrode assembly of any one of the preceding embodiments, wherein the group of current limiters comprises a conductive adhesive.

[0148] EMBODIMENT 13 13. An electrode assembly as described in embodiment 12, wherein the conductive adhesive is comprised of a single layer of conductive adhesive, and each unit of the group of current limiters comprises a different portion of the single layer of conductive adhesive.

[0149] EMBODIMENT 14 14. An electrode assembly as described in embodiment 13, wherein a single layer of conductive adhesive is disposed on the electrode busbar.

[0150] EMBODIMENT 15 13. An electrode assembly as described in embodiment 12, wherein the conductive adhesive of each unit of the group of current limiters is physically separated from the conductive adhesive of each other unit of the group of current limiters.

[0151] EMBODIMENT 16 16. The electrode assembly of embodiment 15, wherein a conductive adhesive is disposed on a portion of each unit of the electrode current collector group.

[0152] EMBODIMENT 17 17. The electrode assembly of any one of embodiments 12-16, wherein the conductive adhesive comprises an adhesive polymer having a conductive material suspended therein.

[0153] EMBODIMENT 18 18. The electrode assembly of embodiment 17, wherein the conductive material comprises carbon black.

[0154] Embodiment 18.1 18. The electrode assembly of embodiment 17, wherein the conductive material comprises metal coated carbon fiber.

[0155] Embodiment 18.2 An electrode assembly as described in embodiment 18.1, wherein the metal coated carbon fiber comprises nickel coated carbon fiber.

[0156] Embodiment 18.3 The electrode assembly of embodiment 18.1 or 18.2, wherein the metal coated carbon fiber has a length and a diameter, and the aspect ratio of the length to diameter is 10:1 or greater.

[0157] Embodiment 18.4 The electrode assembly of embodiment 18.3, wherein the aspect ratio of length to diameter is from 10:1 to 10,000:1, inclusive.

[0158] Embodiment 18.5 The electrode assembly of embodiment 18.3, wherein the aspect ratio of length to diameter is from 50:1 to 5,000:1, inclusive.

[0159] Embodiment 18.6 The electrode assembly of embodiment 18.3, wherein the aspect ratio of length to diameter is from 100:1 to 2,000:1, inclusive.

[0160] Embodiment 18.7 An electrode assembly as described in embodiment 18.3, wherein the aspect ratio of length to diameter is about 850.

[0161] EMBODIMENT 19 18. An electrode assembly as described in embodiment 17, wherein the conductive material comprises nickel particles.

[0162] EMBODIMENT 20 18. The electrode assembly of embodiment 17, wherein the conductive material comprises one or more of carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

[0163] EMBODIMENT 21 18. The electrode assembly of embodiment 17, wherein the conductive material comprises metal particles.

[0164] EMBODIMENT 22 22. The electrode assembly of any one of embodiments 12-21, wherein the conductive adhesive comprises a hot melt adhesive polymer.

[0165] Embodiment 22.1 22. The electrode assembly according to any one of embodiments 12 to 21, wherein the conductive adhesive has a melt flow index, determined according to ASTM D 1238 at 190° C., of 0.1 to 1000 grams (g) / 10 minutes (min).

[0166] Embodiment 22.2 The electrode assembly of embodiment 22.1, wherein the melt flow index is 0.1 to 100 g / 10 min.

[0167] Embodiment 22.3 The electrode assembly of embodiment 22.1, wherein the melt flow index is 0.5 to 20 g / 10 min.

[0168] Embodiment 22.4 The electrode assembly according to any one of embodiments 12 to 22.3, wherein the melting point of the conductive adhesive is between 40°C and 300°C.

[0169] Embodiment 22.5 The electrode assembly of embodiment 22.4, wherein the melting point of the conductive adhesive is 60°C to 200°C.

[0170] Embodiment 22.6 The electrode assembly of embodiment 22.4, wherein the melting point of the conductive adhesive is 70°C to 165°C.

[0171] EMBODIMENT 23 An electrode assembly according to any one of embodiments 12 to 22.6, wherein the conductive adhesive has a resistivity of 0.01 Ω·cm or more.

[0172] EMBODIMENT 24 24. The electrode assembly of any one of embodiments 12 to 23, wherein the conductive adhesive has a resistivity of 1.0 Ω·cm or less.

[0173] EMBODIMENT 25 25. The electrode assembly of any one of embodiments 12 to 24, wherein the conductive adhesive comprises one of ethylene-co-acrylic acid, an ionomer of ethylene-co-acrylic acid, and a polymer of ethylene-co-acrylic acid.

[0174] EMBODIMENT 26 25. The electrode assembly of any one of embodiments 12-24, wherein the conductive adhesive comprises one of ethylene-co-methacrylic acid, an ionomer of ethylene-co-methacrylic acid, and a polymer of ethylene-co-methacrylic acid.

[0175] EMBODIMENT 27 25. The electrode assembly of any one of embodiments 12 to 24, wherein the conductive adhesive comprises a functionalized polyethylene.

[0176] EMBODIMENT 28 25. The electrode assembly of any one of embodiments 12-24, wherein the conductive adhesive comprises a functionalized polypropylene.

[0177] EMBODIMENT 29 12. The electrode assembly according to any one of embodiments 1 to 11, wherein each constituent unit of the current limiter group comprises a conductive film.

[0178] EMBODIMENT 30 30. An electrode assembly according to any one of the preceding embodiments, wherein each constituent unit of the current limiter group is physically located between an electrode busbar and its associated electrode current collector.

[0179] EMBODIMENT 31 31. The electrode assembly of any one of the preceding embodiments, further comprising a group of additional current limiters, each constituent unit of the group of additional current limiters being electrically connected between a different counter electrode current collector and a counter electrode bus bar.

[0180] EMBODIMENT 32 32. An electrode assembly as described in embodiment 31, wherein at a temperature of 25 degrees Celsius (°C), each constituent unit of the additional current limiter group has a resistance greater than 0.25 ohms (Ω).

[0181] EMBODIMENT 33 32. An electrode assembly as described in embodiment 31, wherein at a temperature of 25 degrees Celsius (°C), each constituent unit of the additional current limiter group has a resistance of less than 0.25 ohms (Ω).

[0182] EMBODIMENT 34 34. An electrode assembly according to any one of embodiments 31 to 33, wherein the resistance of each constituent unit of the second current limiter group does not increase at a temperature higher than 25°C.

[0183] EMBODIMENT 35 35. An electrode assembly according to any one of embodiments 31 to 34, wherein the group of additional current limiters comprises an additional conductive adhesive.

[0184] EMBODIMENT 36 36. An electrode assembly as described in embodiment 35, wherein the additional conductive adhesive comprises an additional adhesive polymer having additional conductive material suspended therein.

[0185] EMBODIMENT 37 37. The electrode assembly of embodiment 36, wherein the additional conductive material comprises carbon black.

[0186] Embodiment 37.1 37. The electrode assembly of embodiment 36, wherein the additional conductive material comprises metal coated carbon fiber.

[0187] Embodiment 37.2 An electrode assembly as described in embodiment 37.1, wherein the metal coated carbon fiber comprises nickel coated carbon fiber.

[0188] Embodiment 37.3 The electrode assembly of embodiment 37.1 or 37.2, wherein the metal coated carbon fiber has a length and a diameter, and the aspect ratio of the length to diameter is 10:1 or greater.

[0189] Embodiment 37.4 The electrode assembly of embodiment 37.3, wherein the aspect ratio of length to diameter is from 10:1 to 10,000:1, inclusive.

[0190] Embodiment 37.5 The electrode assembly of embodiment 37.3, wherein the aspect ratio of length to diameter is from 50:1 to 5,000:1, inclusive.

[0191] EMBODIMENT 37.6 The electrode assembly of embodiment 37.3, wherein the aspect ratio of length to diameter is from 100:1 to 2,000:1, inclusive.

[0192] EMBODIMENT 37.7 An electrode assembly as described in embodiment 37.3, wherein the aspect ratio of length to diameter is about 850.

[0193] EMBODIMENT 38 37. An electrode assembly as described in embodiment 36, wherein the additional conductive material comprises nickel particles.

[0194] EMBODIMENT 39 37. The electrode assembly of embodiment 36, wherein the additional conductive material comprises one or more of carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

[0195] EMBODIMENT 40 37. The electrode assembly of embodiment 36, wherein the additional conductive material comprises metal particles.

[0196] EMBODIMENT 41 37. The electrode assembly of embodiment 36, wherein the additional conductive material and the conductive material are the same type of conductive material.

[0197] EMBODIMENT 42 42. The electrode assembly of any one of embodiments 35 to 41, wherein the additional conductive adhesive comprises a hot melt adhesive polymer.

[0198] Embodiment 42.1 42. The electrode assembly according to any one of embodiments 35 to 41, wherein the melt flow index of the additional conductive adhesive, determined according to ASTM D 1238 at 190° C., is 0.1 to 1000 grams (g) / 10 minutes (min).

[0199] Embodiment 42.2 The electrode assembly of embodiment 42.1, wherein the melt flow index is 0.1 to 100 g / 10 min.

[0200] Embodiment 42.3 The electrode assembly of embodiment 42.1, wherein the melt flow index is 0.5 to 20 g / 10 min.

[0201] Embodiment 42.4 The electrode assembly of any one of embodiments 35 to 42.3, wherein the melting point of the additional conductive adhesive is between 40°C and 300°C.

[0202] Embodiment 42.5 The electrode assembly of embodiment 42.4, wherein the melting point of the additional conductive adhesive is between 60°C and 200°C.

[0203] EMBODIMENT 42.6 The electrode assembly of embodiment 42.4, wherein the melting point of the additional conductive adhesive is between 70°C and 165°C.

[0204] EMBODIMENT 43 An electrode assembly according to any one of embodiments 35 to 42.6, wherein the additional conductive adhesive has a resistivity of 0.01 Ω·cm or more.

[0205] EMBODIMENT 44 44. An electrode assembly according to any one of embodiments 35 to 43, wherein the additional conductive adhesive has a resistivity of 1.0 Ω·cm or less.

[0206] EMBODIMENT 45 45. The electrode assembly of any one of embodiments 35 to 44, wherein the additional conductive adhesive comprises one of ethylene-co-acrylic acid, ionomers of ethylene-co-acrylic acid, and polymers of ethylene-co-acrylic acid.

[0207] EMBODIMENT 46 45. The electrode assembly of any one of embodiments 35 to 44, wherein the additional conductive adhesive comprises one of ethylene-co-methacrylic acid, ionomers of ethylene-co-methacrylic acid, and polymers of ethylene-co-methacrylic acid.

[0208] EMBODIMENT 47 45. An electrode assembly according to any one of embodiments 35 to 44, wherein the additional conductive adhesive comprises a functionalized polyethylene.

[0209] EMBODIMENT 48 45. The electrode assembly of any one of embodiments 35 to 44, wherein the additional conductive adhesive comprises a functionalized polypropylene.

[0210] EMBODIMENT 49 35. The electrode assembly of any one of embodiments 31 to 34, wherein each constituent unit of the additional current limiter group comprises a conductive film.

[0211] EMBODIMENT 50 50. An electrode assembly according to any one of embodiments 31 to 49, wherein each constituent unit of the additional current limiter group is physically located between an electrode busbar and an associated electrode current collector of the electrode busbar.

[0212] EMBODIMENT 51 An electrode assembly according to any one of embodiments 1 to 50, further comprising a group of additional electrode structures, each constituent unit of the group of additional electrode structures comprising an electrode active material and an additional electrode current collector, the additional electrode current collector not being connected to a constituent unit of the current limiter group but being electrically connected in parallel to the electrode bus bar.

[0213] EMBODIMENT 52 52. The electrode assembly of any one of the preceding embodiments, wherein the electrode structure comprises a cathode structure, the electrode active material comprises a cathode active material, the electrode current collector comprises a cathode current collector, and the electrode bus bar comprises a cathode bus bar.

[0214] EMBODIMENT 53 52. The electrode assembly of any one of the preceding embodiments, wherein the electrode structure comprises an anode structure, the electrode active material comprises an anode active material, the electrode current collector comprises an anode current collector, and the electrode bus bar comprises a cathode bus bar.

[0215] EMBODIMENT 54 A secondary battery comprising: a sealed battery housing; an electrode assembly according to any one of the preceding embodiments within the sealed housing; and an electrode terminal and a counter electrode terminal outside the sealed battery housing.

[0216] EMBODIMENT 55 A secondary battery for cycling between charged and discharged states having a rated capacity C, comprising: (i) a sealed battery housing; (ii) an electrode assembly including a group of current limiters within the sealed housing; and (iii) an electrode terminal and a counter electrode terminal external to the sealed battery housing. The electrode assembly has mutually perpendicular horizontal, vertical, and vertical axes corresponding respectively to the x-, y-, and z-axes of an imaginary three-dimensional Cartesian coordinate system, and comprises: (i) a group of at least ten electrode structures and a group of at least ten counter electrode structures arranged in a vertically alternating array, (ii) an electrode bus bar electrically connected to the electrode terminals, (iii) a counter electrode bus bar electrically connected to the counter electrode terminals, and (iv) an electrically insulating separator between constituent elements of the electrode groups and the counter electrode groups, and (v) each constituent element of the electrode groups is electrically connected to the electrode bus bar. (vi) an electrode bus bar having a length and a cross-sectional area and adapted to transfer current from the electrode terminal to the electrode group and to transfer pooled current from the electrode group to the electrode terminal; (vii) each constituent unit of the electrode group is electrically connected in parallel to the counter electrode bus bar; and (viii) a counter electrode bus bar having a length and a cross-sectional area and adapted to transfer current from the counter electrode terminal to the counter electrode group and to transfer pooled current from the counter electrode group to the counter electrode terminal. Each constituent unit of the electrode group comprises an electrode current collector having a proximal end, a distal end, a length extending from the proximal end to the distal end of the electrode current collector, a cross-sectional area along the length of the electrode current collector, and a layer of electrode active material on a surface of the electrode current collector, the proximal end of the electrode current collector being electrically connected to the electrode bus bar. Each constituent unit of the counter electrode group comprises a counter electrode current collector and a layer of counter electrode active material on a surface of the counter electrode current collector. The group of current limiters is electrically connected between the electrode busbar and the electrode current collector, and at a temperature of 25 degrees Celsius (°C), each component of the group of current limiters has a resistance greater than 0.25 ohms (Ω).

[0217] EMBODIMENT 56 56. The secondary battery of embodiment 55, wherein the resistance of each component unit of the current limiter group does not increase at a temperature higher than 25°C.

[0218] EMBODIMENT 57 58. The secondary battery of embodiment 56 or embodiment 57, wherein the group of current limiters comprises a conductive adhesive.

[0219] EMBODIMENT 58 58. The secondary battery of embodiment 57, wherein the conductive adhesive is comprised of a single layer of conductive adhesive, and each unit of the group of current limiters comprises a different portion of the single layer of conductive adhesive.

[0220] EMBODIMENT 59 59. The secondary battery of embodiment 58, wherein a single layer of conductive adhesive is disposed on the electrode busbars.

[0221] EMBODIMENT 60 58. The secondary battery of embodiment 57, wherein the conductive adhesive of each unit of the group of current limiters is physically separated from the conductive adhesive of each other unit of the group of current limiters.

[0222] EMBODIMENT 61 61. The secondary battery of embodiment 60, wherein a conductive adhesive is disposed on a portion of each unit of the electrode current collector group.

[0223] EMBODIMENT 62 62. The secondary battery of any one of embodiments 57-61, wherein the conductive adhesive comprises an adhesive polymer having a conductive material suspended therein.

[0224] EMBODIMENT 63 63. The secondary battery of embodiment 62, wherein the conductive material comprises carbon black.

[0225] Embodiment 63.1 63. The secondary battery of embodiment 62, wherein the conductive material comprises metal-coated carbon fiber.

[0226] EMBODIMENT 63.2 The secondary battery of embodiment 63.1, wherein the metal-coated carbon fiber comprises nickel-coated carbon fiber.

[0227] EMBODIMENT 63.3 The secondary battery of embodiment 63.1 or 63.2, wherein the metal coated carbon fiber has a length and a diameter, and an aspect ratio of the length to diameter is 10:1 or greater.

[0228] EMBODIMENT 63.4 The secondary battery of embodiment 63.3, wherein the aspect ratio of length to diameter is from 10:1 to 10,000:1, inclusive.

[0229] EMBODIMENT 63.5 The secondary battery of embodiment 63.3, wherein the aspect ratio of length to diameter is from 50:1 to 5,000:1, inclusive.

[0230] EMBODIMENT 63.6 The secondary battery of embodiment 63.3, wherein the aspect ratio of length to diameter is from 100:1 to 2,000:1, inclusive.

[0231] EMBODIMENT 63.7 The secondary battery of embodiment 63.3, wherein the length-to-diameter aspect ratio is about 850.

[0232] EMBODIMENT 64 63. The secondary battery of embodiment 62, wherein the conductive material comprises nickel particles.

[0233] EMBODIMENT 65 63. The secondary battery of embodiment 62, wherein the conductive material comprises one or more of carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

[0234] EMBODIMENT 66 63. The secondary battery of embodiment 62, wherein the conductive material comprises metal particles.

[0235] EMBODIMENT 67 67. The secondary battery of any one of embodiments 57 to 66, wherein the conductive adhesive comprises a hot melt adhesive polymer.

[0236] EMBODIMENT 67.1 67. The secondary battery according to any one of embodiments 57 to 66, wherein the melt flow index of the conductive adhesive determined according to ASTM D 1238 at 190° C. is 0.1 to 1000 grams (g) / 10 minutes (min).

[0237] EMBODIMENT 67.2 The secondary battery of embodiment 67.1, having a melt flow index of 0.1 to 100 g / 10 min.

[0238] EMBODIMENT 67.3 The secondary battery of embodiment 67.1, having a melt flow index of 0.5 to 20 g / 10 min.

[0239] EMBODIMENT 67.4 The secondary battery according to any one of embodiments 57 to 67.3, wherein the melting point of the conductive adhesive is 40°C to 300°C.

[0240] EMBODIMENT 67.5 The secondary battery of embodiment 67.4, wherein the melting point of the conductive adhesive is 60°C to 200°C.

[0241] EMBODIMENT 67.6 The secondary battery of embodiment 67.4, wherein the melting point of the conductive adhesive is 70°C to 165°C.

[0242] EMBODIMENT 68 The secondary battery of any one of embodiments 57 to 67.6, wherein the conductive adhesive has a resistivity of 0.01 Ω·cm or more.

[0243] EMBODIMENT 69 69. The secondary battery of any one of embodiments 57 to 68, wherein the conductive adhesive has a resistivity of 1.0 Ω·cm or less.

[0244] EMBODIMENT 70 70. The secondary battery of any one of embodiments 57-69, wherein the conductive adhesive comprises one of ethylene-co-acrylic acid, an ionomer of ethylene-co-acrylic acid, and a polymer of ethylene-co-acrylic acid.

[0245] EMBODIMENT 71 70. The secondary battery of any one of embodiments 57-69, wherein the conductive adhesive comprises one of ethylene-co-methacrylic acid, an ionomer of ethylene-co-methacrylic acid, and a polymer of ethylene-co-methacrylic acid.

[0246] EMBODIMENT 72 70. The secondary battery of any one of embodiments 57-69, wherein the conductive adhesive comprises a functionalized polyethylene.

[0247] EMBODIMENT 73 70. The secondary battery of any one of embodiments 57-69, wherein the conductive adhesive comprises a functionalized polypropylene.

[0248] EMBODIMENT 74 57. The secondary battery of embodiment 55 or embodiment 56, wherein each constituent unit of the current limiter group includes a conductive film.

[0249] EMBODIMENT 75 75. The secondary battery of any one of embodiments 55 to 74, wherein each constituent unit of the current limiter group is physically located between an electrode busbar and its associated electrode current collector.

[0250] EMBODIMENT 76 The secondary battery according to any one of embodiments 55 to 75, wherein the electrode assembly further comprises a group of additional current limiters, each constituent unit of the group of additional current limiters being electrically connected between a different counter electrode current collector and a counter electrode bus bar.

[0251] EMBODIMENT 77 77. The secondary battery of embodiment 76, wherein at a temperature of 25 degrees Celsius (° C.), each constituent unit of the additional current limiter group has a resistance greater than 0.25 ohms (Ω).

[0252] EMBODIMENT 78 77. The secondary battery of embodiment 76, wherein at a temperature of 25 degrees Celsius (° C.), each constituent unit of the additional current limiter group has a resistance of less than 0.25 ohms (Ω).

[0253] EMBODIMENT 79 79. The secondary battery according to any one of embodiments 76 to 78, wherein the resistance of each constituent unit of the second current limiter group does not increase at a temperature higher than 25°C.

[0254] EMBODIMENT 80 80. The secondary battery of any one of embodiments 76-79, wherein the group of additional current limiters comprises an additional conductive adhesive.

[0255] Embodiment 81 81. The secondary battery of embodiment 80, wherein the additional conductive adhesive comprises an additional adhesive polymer having additional conductive material suspended therein.

[0256] EMBODIMENT 82 82. The secondary battery of embodiment 81, wherein the additional conductive material comprises carbon black.

[0257] Embodiment 82.1 82. The secondary battery of embodiment 81, wherein the additional conductive material comprises metal-coated carbon fiber.

[0258] EMBODIMENT 82.2 The secondary battery of embodiment 82.1, wherein the metal-coated carbon fiber comprises nickel-coated carbon fiber.

[0259] EMBODIMENT 82.3 The secondary battery of embodiment 82.1 or 82.2, wherein the metal coated carbon fiber has a length and a diameter, and the length to diameter aspect ratio is 10:1 or greater.

[0260] EMBODIMENT 82.4 The secondary battery of embodiment 82.3, wherein the aspect ratio of length to diameter is from 10:1 to 10,000:1, inclusive.

[0261] EMBODIMENT 82.5 The secondary battery of embodiment 82.3, wherein the aspect ratio of length to diameter is from 50:1 to 5,000:1, inclusive.

[0262] EMBODIMENT 82.6 The secondary battery of embodiment 82.3, wherein the aspect ratio of length to diameter is from 100:1 to 2,000:1, inclusive.

[0263] EMBODIMENT 82.7 The secondary battery of embodiment 82.3, wherein the length-to-diameter aspect ratio is about 850.

[0264] EMBODIMENT 83 82. The secondary battery of embodiment 81, wherein the additional conductive material comprises nickel particles.

[0265] EMBODIMENT 84 82. The secondary battery of embodiment 81, wherein the additional conductive material comprises one or more of carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

[0266] EMBODIMENT 85 82. The secondary battery of embodiment 81, wherein the additional conductive material comprises metal particles.

[0267] EMBODIMENT 86 82. The secondary battery of embodiment 81, wherein the additional conductive material and the conductive material are the same type of conductive material.

[0268] EMBODIMENT 87 87. The secondary battery of any one of embodiments 80 to 86, wherein the additional conductive adhesive comprises a hot melt adhesive polymer.

[0269] Embodiment 87.1 87. The secondary battery according to any one of embodiments 80 to 86, wherein the melt flow index of the additional conductive adhesive determined according to ASTM D 1238 at 190° C. is 0.1 to 1000 grams (g) / 10 minutes (min).

[0270] EMBODIMENT 87.2 The secondary battery of embodiment 87.1, wherein the melt flow index is 0.1 to 100 g / 10 min.

[0271] EMBODIMENT 87.3 The secondary battery of embodiment 87.1, wherein the melt flow index is 0.5 to 20 g / 10 min.

[0272] EMBODIMENT 87.4 The secondary battery of any one of embodiments 80 to 87.3, wherein the melting point of the additional conductive adhesive is 40°C to 300°C.

[0273] EMBODIMENT 87.5 The secondary battery of embodiment 87.4, wherein the melting point of the additional conductive adhesive is 60°C to 200°C.

[0274] EMBODIMENT 87.6 The secondary battery of embodiment 87.4, wherein the melting point of the additional conductive adhesive is 70°C to 165°C.

[0275] EMBODIMENT 88 The secondary battery of any one of embodiments 80 to 87.6, wherein the additional conductive adhesive has a resistivity of 0.01 Ω·cm or more.

[0276] EMBODIMENT 89 The secondary battery of any one of embodiments 80 to 88, wherein the additional conductive adhesive has a resistivity of 1.0 Ω·cm or less.

[0277] EMBODIMENT 90 90. The secondary battery of any one of embodiments 80 to 89, wherein the additional conductive adhesive comprises one of ethylene-co-acrylic acid, an ionomer of ethylene-co-acrylic acid, and a polymer of ethylene-co-acrylic acid.

[0278] EMBODIMENT 91 90. The secondary battery of any one of embodiments 80-89, wherein the additional conductive adhesive comprises one of ethylene-co-methacrylic acid, an ionomer of ethylene-co-methacrylic acid, and a polymer of ethylene-co-methacrylic acid.

[0279] EMBODIMENT 92 90. The secondary battery of any one of embodiments 80-89, wherein the additional conductive adhesive comprises a functionalized polyethylene.

[0280] EMBODIMENT 93 90. The secondary battery of any one of embodiments 80-89, wherein the additional conductive adhesive comprises a functionalized polypropylene.

[0281] EMBODIMENT 94 80. The secondary battery of any one of embodiments 76 to 79, wherein each constituent unit of the additional current limiter group comprises a conductive film.

[0282] EMBODIMENT 95 The secondary battery of any one of embodiments 76 to 94, wherein each constituent unit of the additional current limiter group is physically located between an electrode bus bar and an associated electrode current collector of the electrode bus bar.

[0283] EMBODIMENT 96 The secondary battery according to any one of embodiments 55 to 95, wherein the electrode assembly further comprises a group of additional electrode structures, each constituent unit of the group of additional electrode structures comprising an electrode active material and an additional electrode current collector, and the additional electrode current collector is not connected to the constituent unit of the current limiter group but is electrically connected in parallel to the electrode bus bar.

[0284] EMBODIMENT 97 97. The secondary battery of any one of embodiments 55-96, wherein the electrode structure comprises a cathode structure, the electrode active material comprises a cathode active material, the electrode current collector comprises a cathode current collector, and the electrode bus bar comprises a cathode bus bar.

[0285] EMBODIMENT 98 97. The secondary battery of any one of embodiments 55-96, wherein the electrode structure comprises an anode structure, the electrode active material comprises an anode active material, the electrode current collector comprises an anode current collector, and the electrode bus bar comprises a cathode bus bar.

[0286] EMBODIMENT 99 A method for testing an electrode unit cell having a current limiter for use in an electrode assembly for cycling between a charged state and a discharged state, the electrode unit cell comprising an electrode structure, a counter electrode structure, and a spacer between the electrode structure and the counter electrode structure, the current limiter being electrically connected to the electrode structure, and the electrode unit cell having a capacitance C and a voltage V. The method includes electrically connecting the current limiter to the electrode structure, the current limiter having a resistance of 0.25 ohms (Ω) or greater at a temperature of 25 degrees Celsius (°C). Conductive particles are inserted into the location of the electrode unit cell between the electrode structure and the counter electrode structure, and an indenter is positioned above the location of the electrode unit cell where the conductive particles are inserted. The indenter is pressed into the electrode unit cell at a rate of 1.0 millimeter (mm) per second while preventing the electrode unit cell from moving to push the conductive particles through the spacer and into contact with both the electrode unit cell and the counter electrode unit cell. An electrode unit cell having a current limiter fails the test when the electrode unit cell fires, and an electrode unit cell having a current limiter passes the test when the electrode unit cell does not fire.

[0287] EMBODIMENT 100 100. The method of embodiment 99, wherein forcing the indenter into the electrode unit cell comprises forcing the indenter into the electrode unit cell until a voltage drop greater than 80 percent of the voltage V is observed.

[0288] EMBODIMENT 101 101. The method of embodiment 99 or embodiment 100, wherein inserting the conductive particles comprises inserting nickel particles.

[0289] EMBODIMENT 102 102. The method of embodiment 101, wherein inserting the nickel particles comprises inserting the nickel particles, the nickel particles being 2.0 mm x 0.2 mm x 0.1 mm nickel particles shaped like the letter "L."

[0290] EMBODIMENT 103 103. The method of any one of embodiments 99-102, further comprising, when the electrode unit cell is determined to have failed the test, attaching a different current limiter to a similar electrode unit cell having the same capacitance C and voltage V as the electrode unit cell, the different current limiter having a greater resistance than the current limiter at a temperature of 25° C.; positioning an indenter above a location of the similar electrode unit cell where the similar conductive particles were inserted; pressing the indenter into the similar electrode unit cell at a speed of 1.0 mm per second while preventing the similar electrode unit cell from moving; determining that the similar electrode unit cell with the different current limiter has failed the test when the similar electrode unit cell ignites; and determining that the similar electrode unit cell with the different current limiter has passed the test when the similar electrode unit cell does not ignite.

[0291] EMBODIMENT 104 A method of designing an electrode assembly for cycling between a charged state and a discharged state includes assembling an electrode unit cell having a type, the electrode unit cell comprising an electrode structure, a counter electrode structure, and a spacer between the electrode structure and the counter electrode structure, the type being determined by the voltage generated by the electrode unit cell, the capacity of the electrode unit cell, and the materials used to construct the electrode structure, the counter electrode structure, and the spacer. A current limiter is electrically connected to the electrode structure, and at a temperature of 25 degrees Celsius (°C), the current limiter has a resistance of 0.25 ohms (Ω) or greater. A conductive particle is inserted at the location of the electrode unit cell between the electrode structure and the counter electrode structure. An indenter is positioned above the location of the electrode unit cell where the conductive particle is inserted. The indenter is pressed into the electrode unit cell at a speed of 1.0 millimeter (mm) per second while preventing the electrode unit cell from moving to push the conductive particle through the spacer and into contact with both the electrode unit cell and the counter electrode unit cell. An electrode unit cell having a current limiter fails the test when the electrode unit cell fires, and an electrode unit cell having a current limiter passes the test when the electrode unit cell does not fire. When an electrode unit cell having a current limiter passes the test, an electrode structure is assembled that includes a group of electrode unit cells of this type and a group of current limiters, with each current limiter electrically connected to a different electrode unit cell.

[0292] EMBODIMENT 105 Assembling a similar electrode unit cell having the same type as the electrode unit cell; electrically connecting a different current limiter to the similar electrode structure, where the different current limiter has a greater resistance than the current limiter at a temperature of 25° C.; inserting a similar conductive particle at the location of the similar electrode unit cell; positioning an indenter over the location of the similar electrode unit cell where the conductive particle was inserted; and pressing the indenter into the similar electrode unit cell at a rate of 1.0 mm per second while preventing the similar electrode unit cell from moving; and the similar electrode unit cell ignited. 105. The method of claim 104, further comprising: determining that similar electrode unit cells having different current limiters fail the test when the similar electrode unit cells do not ignite; determining that similar electrode unit cells having different current limiters pass the test when the similar electrode unit cells have not ignited; and assembling an electrode structure including a group of electrode unit cells having the same type as the electrode unit cells and a group of different current limiters when the similar electrode unit cells having different current limiters pass the test, wherein each different current limiter is electrically connected to a different electrode unit cell.

[0293] EMBODIMENT 106 Thermal runaway current I through the electrode unit cells, which can cause failure of an electrode assembly containing a group of electrode unit cells if an internal short circuit occurs in one of the electrode unit cells trwherein each electrode unit cell comprises an electrode structure, a counter electrode structure, and a separator structure between the electrode structure and the counter electrode structure. The method includes: (a) inserting a conductive particle at the location of one electrode unit cell between an electrode structure and a counter-electrode structure in an electrode assembly of M unit cells electrically connected in parallel, where M is a positive integer; (b) positioning an indenter above the electrode assembly at the location of the electrode unit cell where the conductive particle was inserted; (c) pressing the indenter into the electrode unit cell at a rate of 1.0 millimeter (mm) per second while preventing the electrode assembly from moving to push the conductive particle through the spacer and into contact with both the electrode unit cell and the counter-electrode unit cell; (d) determining that the electrode assembly fails the test when the electrode assembly ignites and determining that the electrode assembly passes the test when the electrode assembly does not ignite; (e) increasing M by 1 when the electrode assembly passes the test and repeating steps (a)-(e), proceeding to step (f) when the electrode assembly fails the test; and (f) determining a thermal runaway current I based on the electrode assembly including M-1 unit cells. tr and determining:

[0294] EMBODIMENT 107 Based on an electrode assembly containing M-1 unit cells, the thermal runaway current I tr It is important to determine the thermal runaway current I tr as a function of the voltage of the individual unit cells when fully charged and the short-circuit resistance of the electrode unit cells with conductive particles inserted when the electrode assembly contains M-1 unit cells.

[0295] EMBODIMENT 108 A method of designing an electrode assembly including a group of electrode unit cells for cycling between charged and discharged states includes: (a) assembling M electrode unit cells, each electrode unit cell comprising an electrode structure, a counter-electrode structure, and a separator structure between the electrode structure and the counter-electrode structure, where M is a positive integer; (b) electrically connecting the M unit cells in parallel in the electrode assembly; (c) inserting conductive particles at the location of one electrode unit cell between the electrode structure and the counter-electrode structure; (d) positioning an indenter above the electrode assembly at the location of the electrode unit cell where the conductive particles are inserted; and (e) removing the conductive particles from the electrode unit cell. (f) determining that the electrode assembly has failed the test when the electrode assembly ignites and that the electrode assembly has passed the test when the electrode assembly does not ignite; (g) increasing M by 1 when the electrode assembly has passed the test and repeating steps (a) to (g), and proceeding to step (h) when the electrode assembly has failed the test; and (h) determining a thermal runaway current I based on the electrode assembly including M-1 unit cells. tr (i) determining the thermal runaway current I tr and determining to add a resistance in series with each electrode structure when a group of electrode unit cells are assembled into an electrode assembly, the resistance limiting the maximum capacitance of the electrode unit cells to less than 100 kΩ.

[0296] EMBODIMENT 109 Based on an electrode assembly containing M-1 unit cells, the thermal runaway current I tr It is important to determine the thermal runaway current I tr as a function of the voltage of the individual unit cells when fully charged and the short-circuit resistance of the electrode unit cells with conductive particles inserted when the electrode assembly contains M-1 unit cells.

[0297] Embodiment 110 The added resistance is

number

[0298] EMBODIMENT 111 1. An electrode assembly for cycling between charged and discharged states within a normal operating temperature range, the electrode assembly comprising a group of electrode structures, a group of counter electrode structures, a group of current limiters, an electrode busbar, and a counter electrode busbar. Each constituent unit of the electrode structure group comprises an electrode current collector, the electrode current collector being constituted by a constituent unit of the electrode structure group and electrically connected in parallel to the electrode busbar. Each constituent unit of the counter electrode structure group comprises a counter electrode current collector, the counter electrode current collector being constituted by a constituent unit of the counter electrode structure group and electrically connected in parallel to the counter electrode busbar. Each of the electrode current collectors is electrically connected to the electrode busbar by a constituent unit of the group of current limiters, and each constituent unit of the electrode limiter group is configured to limit the current through the electrode current collector to which the constituent unit is attached when the electrode assembly is within a normal operating temperature range above a current threshold I tr has sufficient resistance to limit

[0299] EMBODIMENT 112 An electrode assembly for cycling between charged and discharged states within a normal operating temperature range, the electrode assembly comprising a group of electrode structures, a group of counter electrode structures, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. Each constituent unit of the group of electrode structures comprises an electrode current collector, the electrode current collector being constituted by a constituent unit of the group of electrode structures and electrically connected in parallel to the electrode bus bar. Each constituent unit of the group of counter electrode structures comprises a counter electrode current collector, the counter electrode current collector being constituted by a constituent unit of the group of counter electrode structures and electrically connected in parallel to the counter electrode bus bar. Each constituent unit of the group of current limiters comprises a conductive adhesive electrically connecting the electrode current collector to the electrode bus bar, the conductive adhesive having a resistance greater than zero ohms (Ω) when the electrode assembly is within a normal operating temperature range.

[0300] EMBODIMENT 113 1. An electrode assembly for cycling between charged and discharged states within a normal operating temperature range, the electrode assembly comprising a group of electrode structures, a group of counter electrode structures, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. Each constituent unit of the electrode structure group comprises an electrode current collector, the electrode current collector being constituted by a constituent unit of the electrode structure group and electrically connected in parallel to the electrode bus bar. Each constituent unit of the counter electrode structure group comprises a counter electrode current collector, the counter electrode current collector being constituted by a constituent unit of the counter electrode structure group and electrically connected in parallel to the counter electrode bus bar. The group of current limiters includes at least 10 current limiters. Each of the electrode current collectors is electrically connected to the electrode bus bar by a constituent unit of the group of current limiters, and each constituent unit of the group of current limiters has a resistance of 0.25 ohms (Ω) or greater when the electrode assembly is within a normal operating temperature range.

[0301] EMBODIMENT 114 An electrode assembly for cycling between charged and discharged states within a normal operating temperature range, the electrode assembly comprising: a group of electrode structures, a group of counter electrode structures, a group of separator structures for electrically isolating the group of electrode structures and the group of counter electrode structures, a group of current limiters, an electrode bus bar, and a counter electrode bus bar. Each constituent unit of the group of electrode structures is configured to have a thermal runaway current I tr A threshold voltage V exists between the constituent units of the electrode structure group and the constituent units of the counter electrode structure group. The electrode bus bar and the counter electrode bus bar collectively have a terminal resistance. Each constituent unit of the electrode structure group has an electrode structure resistance and includes an electrode current collector, the electrode current collector being constituted by a constituent unit of the electrode structure group and electrically connected in parallel to the electrode bus bar. Each constituent unit of the counter electrode structure group includes a counter electrode current collector, the counter electrode current collector being constituted by a constituent unit of the counter electrode structure group and electrically connected in parallel to the counter electrode bus bar. Each constituent unit of the current limiter group is electrically connected between a different electrode current collector and the electrode bus bar, and when the electrode assembly is within a normal operating temperature range, each constituent unit of the current limiter group limits the current passing through the constituent unit of the electrode structure group associated with the constituent unit to I. tr less than 1 V, the resistance being determined within a normal operating temperature range as a function of V, the resistance of a short circuit between an electrode structure and an adjacent counter electrode structure, the electrode structure resistance, the counter electrode structure resistance, the terminal resistance, and the number of constituent elements of the electrode structure group connected to the electrode bus bar.

[0302] EMBODIMENT 115 55. The electrode assembly according to any one of the preceding claims, further comprising at least one interfacial layer, the at least one interfacial layer being electrically connected between one or both of: a) the constituent units of the electrode current collector and the constituent units of the group of current limiters; and b) the constituent units of the group of current limiters and the electrode busbar.

[0303] EMBODIMENT 116 116. An electrode assembly as described in embodiment 115, wherein the interface layer comprises a conductive coating.

[0304] EMBODIMENT 117 117. The electrode assembly of embodiment 116, wherein the conductive coating comprises a coating of carbon nanotubes.

[0305] EMBODIMENT 118 117. The electrode assembly of embodiment 116, wherein the conductive coating comprises a carbon-based coating.

[0306] EMBODIMENT 119 119. The electrode assembly of any one of embodiments 116-118, wherein a conductive coating is coated on one or both of the electrode current collector constituent elements and the electrode bus bar.

[0307] Embodiment 120 The secondary battery according to any one of embodiments 55 to 98, further comprising at least one interface layer, the at least one interface layer being electrically connected between one or both of a) the constituent units of the electrode current collector and the group of current limiters, and b) the constituent units of the group of current limiters and the electrode bus bar.

[0308] EMBODIMENT 121 121. The secondary battery of embodiment 120, wherein the interfacial layer comprises a conductive coating.

[0309] EMBODIMENT 122 122. The secondary battery of embodiment 121, wherein the conductive coating comprises a coating of carbon nanotubes.

[0310] EMBODIMENT 123 123. The secondary battery of embodiment 122, wherein the conductive coating comprises a carbon-based coating.

[0311] EMBODIMENT 124 124. The secondary battery of any one of embodiments 121-123, wherein a conductive coating is coated on one or both of the electrode current collector constituent elements and the electrode bus bar.

[0312] EMBODIMENT 125 11. A method for assembling an electrode assembly, the method comprising: stacking a group of unit cells on top of each other in a stacking direction, each constituent unit of the group 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 counter electrode structure comprising a counter electrode current collector and a counter electrode active material layer, the electrode structures and the counter electrode structure extending in a longitudinal direction perpendicular to the stacking direction, and ends of the electrode current collector extending in the longitudinal direction beyond the electrode active material and separator structures; bending an end portion of each electrode current collector in a direction perpendicular to the longitudinal direction of the electrode structure to extend in or opposite to the stacking direction; positioning an electrode bus bar extending in the stacking direction with a surface of the electrode bus bar adjacent to an end portion of the electrode current collector; and applying heat and pressure to the electrode bus bar to adhere the end portion of the electrode current collector to the bus bar via an adhesive layer comprising a resistive polymer material.

[0313] EMBODIMENT 126 126. The method of embodiment 125, wherein the resistive polymer layer comprises a thermoplastic material.

[0314] EMBODIMENT 127 126. The method of embodiment 125, wherein an adhesive layer is formed on a surface of the electrode busbar in contact with the end portion of the electrode current collector.

[0315] EMBODIMENT 128 128. The method of embodiment 127, wherein the resistive polymer material comprises an adhesive polymer and the adhesive layer comprises a conductive material suspended in the adhesive polymer.

[0316] EMBODIMENT 129 129. The method of embodiment 128, wherein the conductive material comprises one or more of carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

[0317] Embodiment 130 129. The method of embodiment 128, wherein the conductive material comprises metal coated carbon fiber.

[0318] EMBODIMENT 131 131. The method of embodiment 130, wherein the metal-coated carbon fibers comprise nickel-coated carbon fibers.

[0319] EMBODIMENT 132 131. The method of embodiment 130, 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, inclusive.

[0320] EMBODIMENT 133 133. The method of embodiment 132, wherein the aspect ratio is from 50:1 to 5,000:1, inclusive.

[0321] EMBODIMENT 134 133. The method of embodiment 132, wherein the aspect ratio is from 100:1 to 2,000:1, inclusive.

[0322] EMBODIMENT 135 The method of embodiment 128, wherein the conductive adhesive has a melt flow index, determined according to ASTM D 1238 at 190° C., of 0.1 to 1000 grams (g) / 10 minutes (min).

[0323] EMBODIMENT 136 The method of embodiment 135, wherein the melt flow index is 0.1 to 100 g / 10 min.

[0324] EMBODIMENT 137 The method of embodiment 135, wherein the melt flow index is from 0.5 to 20 g / 10 min.

[0325] EMBODIMENT 138 129. The method of embodiment 128, wherein the melting point of the conductive adhesive is from 40°C to 300°C.

[0326] EMBODIMENT 139 139. The method of embodiment 138, wherein the melting point of the conductive adhesive is from 60°C to 200°C.

[0327] EMBODIMENT 140 139. The method of embodiment 138, wherein the melting point of the conductive adhesive is from 70°C to 165°C.

[0328] EMBODIMENT 141 126. The method of embodiment 125, wherein bending the end portion of each electrode current collector comprises positioning an electrode bus bar against an unbent end portion of each electrode current collector and applying pressure in a stacking direction toward the electrode current collectors.

[0329] EMBODIMENT 142 126. The method of embodiment 125, wherein an end portion of each counter electrode current collector extends in a longitudinal direction opposite the end portion of the electrode current collector beyond the counter electrode active material and separator structure, and the method further comprises bending the end portion of each counter electrode current collector so that it is approximately perpendicular to the longitudinal direction of the counter electrode structure so that it extends in the stacking direction or opposite the stacking direction; positioning a counter electrode bus bar extending in the stacking direction with a surface of the counter electrode bus bar in contact with the end portion of the counter electrode current collector; and attaching the counter electrode bus bar to the end portion of the counter electrode current collector.

[0330] EMBODIMENT 143 143. The method of embodiment 142, wherein attaching the counter electrode bus bar to the end portion of the counter electrode current collector comprises adhesively attaching the counter electrode bus bar to the end portion of the counter electrode current collector.

[0331] EMBODIMENT 144 143. The method of embodiment 142, wherein attaching the counter electrode bus bar to the end portion of the counter electrode current collector comprises attaching the counter electrode bus bar to the end portion of the counter electrode current collector by welding or soldering.

[0332] EMBODIMENT 145 143. The method of embodiment 142, wherein a surface of the counter electrode busbar in contact with the end portion of the counter electrode current collector has a resistive polymer layer disposed thereon, and attaching the counter electrode busbar to the end portion of the counter electrode current collector comprises applying heat and pressure to the counter electrode busbar to adhere the end portion of the counter electrode current collector to the busbar via the resistive polymer layer.

[0333] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any device or system, and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to 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 do not substantially differ from the literal words of the claims.

Claims

1. 1. An energy storage device comprising: a group of unit cells stacked along a stacking axis, each element of the group of unit cells including an electrode separated from a counter electrode by a separator, the electrode including an electrode current collector and an electrode active material, the counter electrode including a counter electrode current collector and a counter electrode active material, the electrode and the counter electrode each extending in a longitudinal direction perpendicular to the stacking axis, an end of the electrode current collector extending in the longitudinal direction beyond the electrode active material and the separator, and an end of each electrode current collector being folded toward the stacking axis in a direction different from the longitudinal direction of the electrode; an electrode bus bar extending in a direction along the stacking axis and having a surface adjacent to an end of an electrode current collector of the unit cell group; and an adhesive comprising a polymeric material, wherein at least a portion of an end of an electrode current collector is adhered to an electrode bus bar by the adhesive bonding the end of the electrode current collector and the electrode bus bar, and (a) the polymeric material is electrically resistive; (b) the polymeric material comprises a conductive material suspended in the polymeric material; (c) the electrode bus bar is welded or soldered to the end of the electrode current collector; or (d) any combination of (a), (b), and (c); The device that contains

2. The polymeric material is electrically resistive, and optionally the adhesive has an electrical resistivity of 5.0×10 －７ ~5.0 x 10 ３ The device of claim 1, wherein the resistance is Ω·cm.

3. The device of claim 1 , wherein the polymeric material comprises a conductive material suspended in the polymeric material.

4. 4. The device of claim 3, wherein the conductive material comprises a metal, optionally the metal comprises nickel, copper, gold, silver, tin, titanium, molybdenum, platinum, chromium, or aluminum, optionally the metal comprises nickel, and optionally the metal comprises an alloy.

5. 4. The device of claim 3, wherein the conductive material comprises carbon fiber, optionally the carbon fiber is metal-coated, optionally the metal-coated carbon fiber is coated with nickel, copper, gold, silver, tin, titanium, molybdenum, platinum chromium, or aluminum, optionally the metal-coated carbon fiber is coated with nickel, optionally the metal-coated carbon fiber is coated with an alloy.

6. 13. The device of claim 1, wherein the electrode busbar is welded or soldered to an end of the electrode current collector, optionally the busbar is welded to the end of the electrode current collector, optionally the busbar is welded to the end of the electrode current collector to create a weld indicative of a laser weld, a friction weld, or an ultrasonic weld.

7. 10. The device of claim 1, wherein the polymeric material comprises an acid group, and optionally the acid group comprises acrylic acid.

8. The device of claim 1 , wherein the polymeric material comprises a polymer blend.

9. 10. The device of claim 1, wherein the polymeric material comprises a copolymer, optionally the copolymer comprises acrylic acid.

10. The device of claim 1 , wherein the adhesive comprises a film or sheet.

11. 10. The device of claim 1, wherein the electrode active material comprises silicon or graphite and the electrode is an anode.

12. 10. The device of claim 1, wherein the electrode active material comprises silicon and the electrode is an anode.

13. 10. The device of claim 1 , wherein the electrode active material comprises silicon and carbon, the electrode is an anode, optionally the silicon and carbon form a composite, optionally the carbon comprises soft carbon, hard carbon, carbon nanotubes, or any combination thereof, and optionally the electrode active material comprises a silicon carbon composite.

14. 10. The device of claim 1, wherein the electrode active material comprises nanowires, optionally the nanowires are carbon nanowires, and the electrode is an anode, and optionally the nanowires have an aspect ratio of 10:1 to 10,000:

1.

15. 2. The device of claim 1, wherein the normal operating temperature range of the device is from -30 degrees Celsius (°C) to +80°C.

16. The device of claim 1 , wherein the device comprises zinc.

17. 2. The device of claim 1, wherein (I) each of the electrode and counter electrode has (A) a length of about 5 mm to about 500 mm, (B) a width of about 0.01 mm to 2.5 mm, and (C) a height of about 0.05 mm to about 25 mm, and (II) the separator has a thickness of about 4 micrometers to about 50 micrometers.

18. 2. The device of claim 1, wherein the electrode and counter-electrode each have a first length to width ratio of at least 5:1 or greater, a second length to height ratio of at least 5:1 or greater, and a third height to width ratio of at least 0.4:1 or greater.

19. 10. The device of claim 1, wherein the loading of the conductive material in the polymeric material is between 1% and 50%.

20. 10. The device of claim 1, wherein the device comprises a secondary battery comprising a group of unit cells, the secondary battery being a lithium-based battery, and optionally (I) the secondary battery comprises a lithium ion battery, or (II) the secondary battery comprises a lithium polymer battery.

21. A method of manufacturing a device according to any one of claims 1 to 20, comprising using one or more apparatus for manufacturing the device.

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