Collector plate, film roll, secondary battery, battery pack, and automobile

Abstract

The present application provides a current collecting plate, a gel roll, a secondary battery, a battery pack, and an automobile. The current collecting plate includes a main body portion having electrical conductivity, a terminal coupling portion configured to be coupled to an electrode terminal, and a fuse portion connecting the main body portion and the terminal coupling portion. The fuse portion includes at least one cutout portion provided on one surface and an insulating portion provided on at least one surface of the fuse portion.

Description

Technical Field

[0001] This application claims the benefit of Korean Patent Application No. 10-2021-0160968 filed with the Korean Patent Office on November 22, 2021, and also claims the benefit of Korean Patent Application No. 10-2022-0156162 filed with the Korean Patent Office on November 21, 2022, and International Application No. PCT / KR2022 / 018386 filed with the Korean Patent Office on November 21, 2022. All disclosures in the corresponding Korean and international patent applications are contained in this specification.

[0002] This invention relates to current collectors, gel rolls, secondary batteries, battery packs, and automobiles. Background Technology

[0003] In addition to portable devices, secondary batteries based on the product group, which are highly convenient to use and have high energy density and other electrical properties, are also widely used in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric drive sources.

[0004] This type of rechargeable battery not only has the primary advantage of significantly reducing the use of fossil fuels, but also the advantage of producing no byproducts when using energy. Therefore, it has attracted much attention as a new energy source that is environmentally friendly and improves energy efficiency.

[0005] Currently, widely used types of rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of a single rechargeable battery cell, or a single battery cell, is approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Furthermore, depending on the required charge / discharge capacity of the battery pack, sometimes multiple battery cells are connected in parallel to form a battery pack. Therefore, depending on the required output voltage and / or charge / discharge capacity, the number of battery cells and the electrical connection method in the aforementioned battery packs can be designed in various ways. Summary of the Invention

[0006] Technical problems to be solved

[0007] The present invention provides a current collector with a fuse portion having an improved probability of short circuit, a gel roll, a secondary battery, a battery pack, and an automobile.

[0008] means of solving technical problems

[0009] One embodiment of the present invention provides a current collector, comprising:

[0010] The main body is conductive;

[0011] Terminal connection portion, which is configured to be connected to electrode terminals; and

[0012] The fuse section connects the main body section and the terminal connection section.

[0013] The aforementioned fuse portion includes at least one cut-off portion on one side and an insulating portion on at least one side of the aforementioned fuse portion.

[0014] Another embodiment of the present invention provides a gel roll comprising: an electrode assembly having a structure formed by stacking and winding a positive electrode, a separation membrane and a negative electrode; and a current collector according to the above embodiment, disposed on at least one end side of the electrode assembly.

[0015] Another embodiment of the present invention provides a secondary battery, a battery pack, and an automobile including the gel roll according to the above embodiments.

[0016] Invention Effects

[0017] According to various embodiments of the present invention, a fuse portion is included that can cut off the current path by melting due to heat generated when an external short circuit occurs. The fuse portion also has an insulating portion on at least one side facing the electrode assembly, thereby preventing heat generated in the fuse portion from being transferred to the electrode assembly, which could cause deformation or melting of the electrode assembly and separation of the film. Furthermore, it also prevents short circuits caused by fragments or pieces of current collector material falling towards the electrode assembly during the melting of the fuse portion.

[0018] As described above, the heat generated when an external short circuit occurs can be stably handled. Therefore, by forming the tab structure of the electrode included in the electrode assembly as an uncoated portion on the current collector without coating of electrode active material, the current applied to the battery can be increased. As a result, the battery size can be increased, high energy density can be achieved, and costs can be reduced. Attached Figure Description

[0019] Figure 1 This is a diagram illustrating a simplified structure of a current collector according to an embodiment of the present invention.

[0020] Figure 2 This is a diagram showing the configuration of an insulating portion in a current collector plate according to an embodiment of the present invention, where the insulating portion is an insulating strip.

[0021] Figure 3 This is a diagram illustrating the structure of an insulating layer in a current collector plate according to an embodiment of the present invention.

[0022] Figure 4This is a diagram that briefly illustrates the location of the cut-off portion in a current collector plate included in a gel roll according to an embodiment of the present invention.

[0023] Figure 5 This is a diagram illustrating a simplified configuration of a secondary battery according to an embodiment of the present invention.

[0024] Figure 6 yes Figure 5 A longitudinal cross-sectional view of the secondary battery.

[0025] Figure 7 It shows including Figure 6 A simplified diagram of the structure of a secondary battery pack.

[0026] Figure 8 It shows including Figure 7 A simplified diagram of the battery pack structure of a car.

[0027] Marker description

[0028] 1: Secondary battery

[0029] 2: Battery pack casing

[0030] 3: Battery pack

[0031] 5: Cars

[0032] 10: Electrode assembly

[0033] 10': Gel Roll

[0034] C: Core section

[0035] CR: Edge of the core

[0036] O: Outer corner

[0037] 11: Positive electrode

[0038] 12: Negative electrode

[0039] 13: Separation membrane

[0040] 20: Battery can

[0041] 21: Rolled edge

[0042] 22: Crimping section

[0043] 30: Seals

[0044] 40: Electrode terminal

[0045] 50: Positive current collector

[0046] 60: Insulator

[0047] 70: Insulating gasket

[0048] 80: Negative current collector

[0049] 90: Sealing gasket

[0050] 100: Current collector

[0051] 110: Main body

[0052] 120: Terminal joint

[0053] 130: Fuse Section

[0054] 140: Resected area

[0055] 140L: Capable of removing the resection area

[0056] 150: Insulation section

[0057] 151: Insulating tape

[0058] 152: Insulation layer

[0059] 160: Groove Detailed Implementation

[0060] The terms and words used in this specification and claims should not be limited to their ordinary or dictionary meanings. Given the principle that inventors may appropriately define terms and concepts in order to best describe their invention, they should be interpreted as meanings and concepts consistent with the technical ideas of this invention.

[0061] Throughout this specification, when a part is described as "including" a certain constituent element, it means, unless otherwise stated, that other constituent elements may also be included, rather than excluding other constituent elements.

[0062] Furthermore, the terms “~part” and “~device” used in the instruction manual refer to units that perform at least one function or action.

[0063] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings.

[0064] An embodiment of the present invention provides a current collector board, comprising: a conductive main body portion; a terminal connection portion configured to be connected to an electrode terminal; and a fuse portion connecting the main body portion and the terminal connection portion, wherein the fuse portion includes at least one cut-out portion provided on one side and an insulating portion provided on at least one side of the fuse portion.

[0065] For the aforementioned conductive main body, as long as it is a component that enables electrical connection between the electrode tabs of the secondary battery and the external terminals within the current collector plate, its structure or material is not limited. For example, the edge of the main body can be rounded to correspond to the shape of one end of the electrode assembly, the interior can be filled with conductive material, and it can also have a shape that opens up a local area as needed.

[0066] The aforementioned insulating part may be provided on only one side of the aforementioned fuse part, or it may be provided on two or more sides or all sides.

[0067] The aforementioned fuse portion has at least one cut-off portion on one side, thereby cutting off the current path by melting due to heat generated when an external short circuit occurs. If the current path is cut off, the voltage of the secondary battery cannot be measured, and abnormal resistance values ​​can be measured. Therefore, it can prevent the heat generated in the aforementioned fuse portion from being transferred to the electrode assembly, thereby preventing the electrode assembly from deforming or melting the separation film. It can also prevent the problem of fragments or debris of the current collector material falling towards the electrode assembly and causing a short circuit during the melting of the aforementioned fuse portion.

[0068] Conversely, existing current collectors do not have the aforementioned cut-out portion, so secondary batteries including them have the following problem: heat is transferred to the electrode assembly due to the heating of the positive electrode tab, resulting in the melting of the insulator.

[0069] Figure 1 This is a diagram illustrating a simplified structure of a current collector according to an embodiment of the present invention.

[0070] Reference Figure 1 The current collector 100 includes a conductive main body 110; a terminal connection 120 connected to the electrode terminal 40; and a fuse part 130 connecting the main body 110 and the terminal connection 120. The fuse part 130 includes at least one cut-out portion 140 on one side and an insulating portion (not shown) on at least one side of the fuse part.

[0071] The structure of the main body 110 is not limited as long as it is a component that enables electrical connection between the electrode tabs of the secondary battery and the external terminals in the current collector plate 100. As an example, the edge of the main body 110 may be rounded, the interior may be filled with conductive material, and it may also have a shape that opens up local areas as needed.

[0072] For the aforementioned fuse part 130, as long as it is a component connecting the aforementioned main body part 110 and the aforementioned terminal connection part 120, its structure, material, or number is not limited. As an example, the aforementioned fuse part 130 can utilize multiple connections between the aforementioned main body part 110 and the aforementioned terminal connection part 120 in multiple directions, and the number of connections is not limited, but at least one part can connect the aforementioned main body part 110 and the aforementioned terminal connection part 120.

[0073] Reference Figure 1 In this case, the cut-out portion 140 may refer to the portion in which a V-shaped groove is etched in the fuse portion 130. The fuse portion 130 has at least one cut-out portion 140 on one side, thereby cutting off the current path by melting the heat generated when a short circuit occurs externally.

[0074] Furthermore, the aforementioned fuse portion 130 has an insulating portion on at least one side facing the electrode assembly, thereby preventing the heat generated in the fuse portion 130 from being transferred to the electrode assembly, which could cause the electrode assembly to deform or melt the separation film. It can also prevent fragments or pieces of the current collector 100 material from falling toward the electrode assembly during the melting of the fuse portion 130, which could cause a short circuit.

[0075] One embodiment of the present invention provides a current collector, wherein the insulating portion (not shown) is provided on the opposite side of the fuse portion 130, which is provided with the cut-off portion 140.

[0076] A cut-off portion 140 may be provided on one side of the fuse portion 130, and an insulating portion may be provided on the opposite side of the side with the cut-off portion 140. As an example, the opposite side of the fuse portion 130 with the cut-off portion 140 may be the side facing the electrode assembly.

[0077] The aforementioned fuse portion 130 has at least one cut-off portion 140 on one side, which can cut off the current path by melting the heat generated when a short circuit occurs externally. On the opposite side of the cut-off portion 140, an insulating portion is provided, which can prevent the heat generated in the fuse portion 130 from being transferred to the electrode assembly, thereby preventing the electrode assembly from deforming or melting the separation film. It can also prevent fragments or debris from falling towards the electrode assembly and causing a short circuit.

[0078] According to one embodiment of the present invention, the insulating part is an insulating tape.

[0079] Figure 2 This is a diagram showing the configuration of an insulating portion in a current collector plate according to an embodiment of the present invention, where the insulating portion is an insulating strip.

[0080] Reference Figure 2The example illustrates a structure in which an insulating tape 151 is adhered to the current collector 100. According to one example, the insulating tape 151 can be adhered to a fuse portion 130 with the fuse portion 130 upright in a direction perpendicular to the surface of the current collector 100.

[0081] The insulating tape 151 can be attached to one side or the opposite side of the fuse part 130 provided with the cut-out part 140, or it can be attached to the upper surface or the opposite side of the cut-out part 140.

[0082] According to one embodiment of the present invention, the insulating portion is an insulating layer. In this case, the insulating layer may have a structure provided in a groove formed on at least one side of the fuse portion.

[0083] According to one embodiment of the present invention, the groove is formed on the opposite side of the fuse portion having the cut-off portion, and the groove may be formed at a position corresponding to the cut-off portion on the opposite side of the fuse portion having the cut-off portion.

[0084] Figure 3 This is a diagram illustrating the structure of an insulating layer in a current collector plate according to an embodiment of the present invention.

[0085] Reference Figure 3 An example is shown of a structure in which an insulating layer 152 is provided in a groove 160 on one side of the fuse portion 130. The groove 160 can be formed by creating a height difference through a forging process.

[0086] The groove 160 may be formed on the opposite side of the fuse portion 130 which is provided with the cut-off portion 140. The groove 160 may be formed at a position corresponding to the cut-off portion 140 on the opposite side of the fuse portion 130 which is provided with the cut-off portion 140. For example, it may be formed at the position where the cut-off portion 140 and the groove 160 face each other in the cross section of the fuse portion 130.

[0087] When viewed from the side section of the fuse portion 130, based on the overall thickness of the fuse portion, the thickness of the groove portion 160 can be made to be less than or equal to the thickness of the fuse portion 130 remaining after the cut-out portion 140 is formed.

[0088] When the insulating layer 152 is provided in the groove 160 formed at the above position, it can prevent the heat generated in the fuse portion 130 from being transferred to the electrode assembly, thereby preventing the electrode assembly from deforming or melting the separation film. It can also prevent the fragments or pieces of the current collector 100 raw material from falling towards the electrode assembly during the melting of the fuse portion 130, thereby preventing a short circuit.

[0089] According to one embodiment of the present invention, the materials of the above-mentioned insulating tape and insulating layer are not particularly limited as long as they are substances that can perform the function of insulation.

[0090] According to one embodiment of the present invention, the insulating layer is an adhesive polymer, which includes one or more polymers selected from the group consisting of polyimide (PI), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), and perfluoroalkoxy (PFA).

[0091] When the aforementioned materials are included, the insulating layer can possess heat resistance and chemical resistance within the secondary battery. Furthermore, it can prevent heat generated in the fuse section from being transferred to the electrode assembly, thus preventing deformation of the electrode assembly or melting of the separation membrane. It can also prevent short circuits caused by fragments or pieces of the current collector material falling towards the electrode assembly during the melting of the fuse section.

[0092] According to one embodiment of the present invention, the polypropylene (PP) includes polypropylene maleic anhydride (PP-MAH) that can be heat-bonded.

[0093] When the aforementioned compound is included, the adhesive polymer can be heat-bonded and possesses internal heat resistance and chemical resistance within the secondary battery. Furthermore, the heat generated at the fuse section allows the adhesive polymer to form an insulating layer, thus preventing heat transfer to the electrode assembly, which could cause deformation or melting of the separation membrane. It also prevents short circuits caused by fragments or pieces of current collector material falling towards the electrode assembly during fuse melting.

[0094] Another embodiment of the present invention provides a gel roll comprising an electrode assembly having a structure in which a positive electrode, a separation membrane and a negative electrode are stacked and wound, and a current collector according to the above embodiment disposed at at least one end of the electrode assembly.

[0095] According to an embodiment of the present invention, preferably, the insulating portion is provided on at least one side of the current collector plate facing the electrode assembly. Providing the insulating portion on at least one side facing the electrode assembly prevents the heat from the fuse melting due to an external short circuit, as well as any fragments or debris from the current collector plate, from affecting the electrode assembly.

[0096] According to one embodiment of the present invention, on one side of the fuse portion, the cut-off portion is provided in the region extending from the periphery of the core portion of the electrode assembly to the outer corner portion of the electrode assembly.

[0097] The aforementioned cut-off portion can be located at any position on one side of the fuse portion, without limitation. Preferably, the cut-off portion can be located in the area from the edge of the core portion of the electrode assembly to the outer corner of the electrode assembly on one side of the fuse portion, and an insulating portion is provided at the corresponding position in the aforementioned area, thereby preventing the heat from the fuse portion melting due to external short circuit and the impact of fragments or debris from the current collector on the electrode assembly, thus further ensuring safety.

[0098] Figure 4 This is a diagram that briefly illustrates the location of the cut-off portion in a current collector plate included in a gel roll according to an embodiment of the present invention.

[0099] Reference Figure 4 On one side of the fuse section 130, a cut-off portion is provided in the area 140L from the perimeter CR of the core portion of the electrode assembly to the outer corner O of the electrode assembly. Thus, when the fuse section melts due to heat caused by an external short circuit, the insulating portion provided at the position corresponding to the cut-off portion can prevent the corresponding heat and the fragments or debris of the current collector from affecting the electrode assembly.

[0100] Another embodiment of the present invention provides a secondary battery comprising a gel roll according to the above embodiments.

[0101] Figure 5 This is a diagram illustrating a simplified configuration of a secondary battery according to an embodiment of the present invention. Figure 6 yes Figure 5 A longitudinal cross-sectional view of the secondary battery.

[0102] Reference Figure 5 as well as Figure 6 The secondary battery 1 according to an embodiment of the present invention includes an electrode assembly 10, a battery canister 20, a sealing member 30, and electrode terminals 40. The gel roll may include the electrode assembly 10 and a positive current collector 50. In addition to the above-described constituent elements, the secondary battery 1 may further include an insulating member 60 and / or an insulating gasket 70 and / or a negative current collector 80 and / or a sealing gasket 90.

[0103] According to one embodiment of the present invention, the current collector can be the above-described positive current collector 50.

[0104] Reference Figure 5 as well as Figure 6 The electrode assembly 10 includes a positive electrode 11, a negative electrode 12, and a separation membrane sandwiched between the positive electrode 11 and the negative electrode 12.

[0105] The aforementioned positive electrode 11 and negative electrode 12 can have a sheet shape. The aforementioned electrode assembly 10 can have, for example, a jelly roll shape. That is, the aforementioned electrode assembly 10 can be manufactured by winding a laminate formed by sequentially stacking a positive electrode 11, a separation membrane, a negative electrode 12, and a separation membrane at least once, with the core portion C as a reference. In this case, an additional separation membrane can be provided on the outer peripheral surface of the aforementioned electrode assembly 10 for insulation from the battery canister 20.

[0106] The aforementioned positive electrode 11 and negative electrode 12 may include uncoated portions without an active material layer at their long side ends. The aforementioned positive electrode 11 and negative electrode 12 may also include coated portions with an active material layer in areas other than the uncoated portions.

[0107] Specifically, the positive electrode 11 includes a positive current collector and a positive active material coated on one or both sides of the positive current collector. The area on the positive current collector coated with the positive active material is referred to as the coated portion of the positive electrode 11. An uncoated portion without positive active material may exist at one end of the positive current collector in the width direction (the direction parallel to the Z-axis). At least a portion of the uncoated portion serves as an electrode tab. That is, the uncoated portion functions as the uncoated portion of the positive electrode 11. The uncoated portion of the positive electrode 11 is located at the upper part of the electrode assembly 10 housed within the battery canister 20 in the height direction (the direction parallel to the Z-axis).

[0108] The aforementioned negative electrode 12 includes a negative current collector and a negative active material coated on one or both sides of the negative current collector. The area on the negative current collector coated with the negative active material is referred to as the coated portion of the negative electrode 12. An uncoated portion without negative active material may exist at the other end of the negative current collector in the width direction (parallel to the Z-axis). At least a portion of the uncoated portion serves as an electrode tab. That is, the uncoated portion functions as the uncoated portion of the negative electrode 12. The uncoated portion of the negative electrode 12 is located at the lower part of the electrode assembly 10 housed within the battery canister 20 in the height direction (parallel to the Z-axis).

[0109] The uncoated portion of the positive electrode 11 and the uncoated portion of the negative electrode 12 may protrude in opposite directions. For example, refer to... Figure 6The uncoated portion of the positive electrode 11 can protrude upwards in the height direction (parallel to the Z-axis) of the electrode assembly 10, and the uncoated portion of the negative electrode 12 can protrude downwards in the height direction (parallel to the Z-axis) of the electrode assembly 10. Therefore, the uncoated portions of the positive and negative electrodes can extend and protrude in opposite directions along the width direction of the electrode assembly 10, i.e., the height direction (parallel to the Z-axis) of the secondary battery 1.

[0110] In this invention, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate can be any active material known in the art, without any limitation.

[0111] As a non-limiting example of the above-mentioned positive electrode active material, conventional positive electrode active materials previously used for the positive electrode of electrochemical elements can be used, especially lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or lithium composite oxides combining the above.

[0112] In one example, the positive electrode active material may include materials with the general chemical formula A[A] x M y ]O 2+z The alkali metal compound represented (A includes at least one element selected from Li, Na, and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; x ≥ 0, 1 ≤ x + y ≤ 2, -0.1 ≤ z ≤ 2; the stoichiometric coefficients of the components contained in x, y, z, and M are selected in such a way that the compound maintains electrical neutrality).

[0113] In another example, the positive electrode active material could be an alkali metal compound xLiM disclosed in US6,677,082, US6,680,143, etc. 1 O2-(1-x)Li2M 2 O3(M 1 Includes at least one element having an average oxidation state of 3; M 2 Includes at least one element having an average oxidation state of 4; 0 ≤ x ≤ 1).

[0114] In yet another example, the positive electrode active material can be in the form of the general chemical formula LiAM. 1 x Fe 1-x M 2 yP 1-y M 3 zO 4-z (M 1comprising at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M 2 comprising at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M 3 comprising halogen elements that selectively include F; 0 < a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y < 1, 0 ≤ z < 1; the stoichiometric coefficients of the components in a, x, y, z, M 1 , M 2 and M 3 and M are selected in such a way that the compound maintains electrical neutrality) or lithium metal phosphate represented by Li3M2(PO4)3 [M comprises at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg, and Al].

[0115] Preferably, the positive electrode active material may include primary particles and / or secondary particles aggregated from primary particles.

[0116] As a non-limiting example of the negative electrode active material, the usual negative electrode active materials previously used for the negative electrode of an electrochemical element can be used. In particular, lithium metal or lithium alloy, carbon, petroleum coke, activated carbon, graphite, or other lithium-adsorbing substances such as other carbon materials can be used.

[0117] In one example, carbon materials, lithium metal or lithium metal compounds, silicon or silicon compounds, tin or tin compounds, etc. can be used as the negative electrode active material. Metal oxides such as TiO2 and SnO2 with a potential less than 2V can also be used as the negative electrode active material. As the carbon material, low-crystalline carbon, high-crystalline carbon, etc. can be used.

[0118] The separation membrane can use a porous polymer film. For example, a porous polymer film made of a polyolefin-based polymer such as an ethylene monomer polymer, a propylene monomer polymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc. can be used alone, or they can be laminated and used. As another example, the separation membrane can use a usual porous non-woven fabric, such as a non-woven fabric composed of high-melting-point glass fibers, polyethylene terephthalate fibers, etc.

[0119] At least one surface of the separation membrane may include a coating of inorganic particles. Furthermore, the separation membrane itself may be composed of a coating of inorganic particles. The particles constituting the coating may have a structure bonded to a binder, thereby creating an interstitial volume between adjacent particles.

[0120] Inorganic particles can be composed of inorganic materials with a dielectric constant of 5 or higher. As a non-limiting example, the aforementioned inorganic particles may include those selected from Pb(Zr, Ti)O3 (PZT), Pb... 1-x La x Zr 1-y Ti y O3(PLZT), PB(Mg3Nb) 2 / 3 It refers to at least one substance in the group consisting of O3-PbTiO3 (PMN-PT), BaTiO3, hafnia (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0121] Electrolytes can be those with A + B - Salts with similar structures. Among them, A... + Including Li + Na + K + Ions consisting of basic metal cations or combinations thereof. Additionally, B... - Including the choice of F - Cl - ,Br - I - NO3 - N(CN)2 - BF4 - ClO4 - AlO4 - AlCl4 - PF6 - SbF6 - AsF6 - BF2C2O4 - BC4O8 - (CF3)2PF4- - (CF3)3PF3 - (CF3)4PF2 - (CF3)5PF - (CF3)6P - CF3SO3 - C4F9SO3, CF3CF2SO3 --(CF3SO2)2N - (FSO2)2N - CF3CF2(CF3)2CO - (CF3SO2)2CH - (SF5)3C - (CF3SO2)3C - CF3(CF2)7SO3 - CF3CO2 - CH3CO2, SCN - and (CF3CF2SO2)2N - - Any one or more anions that make up the group.

[0122] Electrolytes can also be used in organic solvents. Suitable organic solvents include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or mixtures thereof.

[0123] Reference Figure 5 as well as Figure 6 The battery can 20 is a generally cylindrical container with an open portion at its lower end, and is made of a conductive material such as metal. For example, the battery can 20 may be made of aluminum. The bottom portion of the battery can 20 with the open portion is referred to as the open end. The side surfaces (outer peripheral surfaces) and the top surface of the battery can 20 can be integrally formed. The top surface of the battery can 20 (the surface parallel to the XY plane) has a generally flat shape. The top surface located on the opposite side of the open end is referred to as the closed end. The battery can 20 houses the electrode assembly 10 and the electrolyte through the open portion formed at the bottom.

[0124] The battery canister 20 is electrically connected to the electrode assembly 10. For example, the battery canister can be electrically connected to the negative electrode 12 of the electrode assembly 10. In this case, the battery canister 20 can have the same polarity as the negative electrode 12.

[0125] Reference Figure 6 The battery canister 20 may include a rolled edge portion 21 and a crimping portion 22 formed at its lower end. The rolled edge portion 21 is located at the lower part of the electrode assembly 10. The rolled edge portion 21 is formed by pressing the outer peripheral surface of the battery canister 20 in. The rolled edge portion 21 serves to prevent the electrode assembly 10, which may have a size approximately corresponding to the width of the battery canister 20, from falling off through the opening formed at the lower end of the battery canister 20, and can function as a support portion for placing the sealing member 30.

[0126] The aforementioned crimping portion 22 is formed on the lower part of the rolled edge portion 21. The aforementioned crimping portion 22 has a shape that extends and bends in such a way as to wrap around the outer peripheral surface of the seal 30 disposed below the rolled edge portion 21 and a portion of the lower surface of the seal 30.

[0127] It should be noted that the present invention does not exclude the possibility that the battery can 20 does not have such a rolled edge portion 21 and / or a crimped portion 22. That is, in the present invention, when the battery can 20 does not have a rolled edge portion 21 and / or a crimped portion 22, the fixing of the electrode assembly 10 and / or the sealing of the battery can 20 can be achieved by additionally employing, for example, a component that functions as a limiter for the electrode assembly 10. Furthermore, if the secondary battery 1 of the present invention includes a sealing member 30, the fixing of the electrode assembly 10 and / or the sealing of the battery can 20 can be achieved by additionally employing, for example, a structure that can accommodate the sealing member 30 and / or welding between the battery can 20 and the sealing member 30. That is, the aforementioned sealing member can seal the open end of the battery can.

[0128] Reference Figure 6 To ensure rigidity, the aforementioned seal 30 can be made of metal, for example. The aforementioned seal 30 can cover the open end formed at the lower end of the battery canister 20. That is, the aforementioned seal 30 constitutes the lower surface of the secondary battery 1.

[0129] In the secondary battery 1 of the present invention, the sealing member 30 is non-polar even when made of a conductive metal. Non-polarity means that the sealing member 30 is electrically insulated from the battery canister 20 and the electrode terminals 40.

[0130] Therefore, the aforementioned seal 30 does not function as the electrode terminal 40, i.e., the positive or negative terminal. Thus, the aforementioned seal 30 does not need to be electrically connected to the electrode assembly 10 and the battery canister 20, and its material is not necessarily a conductive metal.

[0131] When the battery can 20 of the present invention has a rolled edge portion 21, the sealing member 30 can be placed on the rolled edge portion 21 formed on the battery can 20. Furthermore, when the battery can 20 of the present invention has a crimping portion 22, the sealing member 30 can be fixed by the crimping portion 22. To ensure the airtightness of the battery can 20, a sealing gasket 90 can be sandwiched between the sealing member 30 and the crimping portion 22 of the battery can 20. On the other hand, as explained above, the battery can 20 of the present invention may not have a rolled edge portion 21 and / or a crimping portion 22. In this case, to ensure the airtightness of the battery can 20, the sealing gasket 90 can be sandwiched between the fixing structure provided on the open side of the battery can 20 and the sealing member 30.

[0132] Reference Figure 5 as well as Figure 6 The electrode terminal 40 can be electrically connected to another of the positive electrode 11 and the negative electrode 12. That is, the electrode terminal 40 can have a polarity opposite to that of the battery canister 20. For example, the electrode terminal 40 can be electrically connected to the positive electrode 11 of the electrode assembly 10. In addition, the surface of the electrode terminal 40 can be exposed to the outside.

[0133] The electrode terminal 40 can be made of a conductive metal. For example, the electrode terminal 40 can penetrate approximately the center of the closed end formed at the upper end of the battery can 20. A portion of the electrode terminal 40 can protrude upwards from the battery can 20, while the remaining portion can be located inside the battery can 20. The electrode terminal 40 can be fixed to the inner surface of the closed end of the battery can 20, for example, by riveting. The electrode terminal 40 can penetrate the insulating member 60 and be combined with the positive current collector 50 or the uncoated portion of the positive electrode 11. In this case, the electrode terminal 40 can have a positive electrode.

[0134] Therefore, the electrode terminal 40 described above can function as the positive terminal in the secondary battery 1 of the present invention. In the case where the electrode terminal 40 has a positive electrode, the electrode terminal 40 is electrically insulated from the battery canister 20, which has a negative electrode. Electrical insulation between the electrode terminal 40 and the battery canister 20 can be achieved in various ways.

[0135] As another example, insulation can be achieved by sandwiching an insulating gasket 70, as described later, between the electrode terminal 40 and the battery canister 20. Alternatively, insulation can be achieved by forming an insulating coating locally on the electrode terminal 40. Or, the electrode terminal 40 can be structurally and securely fixed so that it cannot contact the battery canister 20. Alternatively, multiple methods described above can be used simultaneously.

[0136] Reference Figure 6The aforementioned positive current collector 50 can be attached to the upper part of the electrode assembly 10. For example, the aforementioned positive current collector 50 can be attached to the uncoated portion of the positive electrode 11 on the upper part of the electrode assembly 10. The aforementioned positive current collector 50 can be made of a conductive metal material. Although not shown, the aforementioned positive current collector 50 can have a plurality of protrusions and recesses radially formed on its lower surface.

[0137] When the above-mentioned unevenness is formed, the positive electrode current collector 50 can be pressed to press the unevenness into the uncoated part provided on the positive electrode 11.

[0138] According to another embodiment of the present invention, the secondary battery 1 may not include the positive electrode current collector 50. In this case, the uncoated portion of the positive electrode 11 can be directly electrically connected to the electrode terminal 40.

[0139] Reference Figure 6 The aforementioned positive electrode current collector 50 can be bonded to the end of the uncoated portion of the positive electrode 11. The bonding between the uncoated portion of the positive electrode 11 and the positive electrode current collector 50 can be achieved, for example, by laser welding. The laser welding can be performed by melting a portion of the base material of the positive electrode current collector 50, or with solder sandwiched between the positive electrode current collector 50 and the uncoated portion. In this case, preferably, the solder has a lower melting point than both the positive electrode current collector 50 and the uncoated portion. Alternatively, resistance welding, ultrasonic welding, etc., can be used in addition to laser welding, but the welding method is not limited to these methods.

[0140] Reference Figure 6 The insulating component 60 can be disposed between the upper end of the electrode assembly 10 and the inner side of the battery can 20, or combined between the positive current collector 50 on the upper part of the electrode assembly 10 and the inner side of the battery can 20. The insulating component 60 prevents contact between the uncoated portion of the positive electrode 11 and the battery can 20, and / or contact between the positive current collector 50 and the battery can 20. That is, the insulating component 60 is configured to be housed inside the battery can 20 and blocks the electrical connection between the uncoated portion of the positive electrode 11 and the battery can 20. Therefore, the insulating component 60 can be made of a material with insulating properties. For example, the insulating component 60 can include a polymer material.

[0141] Reference Figure 5 as well as Figure 6 The insulating gasket 70 is sandwiched between the battery can 20 and the electrode terminal 40 to prevent the battery can 20 and the electrode terminal 40, which have opposite polarities, from contacting each other. That is, the insulating gasket 70 blocks the electrical connection between the battery can 20 and the terminal 40. As a result, the upper surface of the battery can 20, which has a generally flat shape, can function as the negative electrode terminal 40 of the secondary battery 1.

[0142] Reference Figure 6 The aforementioned negative electrode current collector 80 can be attached to the lower part of the electrode assembly 10. The aforementioned negative electrode current collector 80 can be made of a conductive metal material. The aforementioned negative electrode current collector 80 can be connected to the uncoated portion provided on the negative electrode 12. Furthermore, the aforementioned negative electrode current collector 80 can be electrically connected to the battery canister 20. Figure 2 As shown, the aforementioned negative current collector 80 can be fixed by being sandwiched between the inner side of the battery can 20 and the sealing gasket 90. Alternatively, the aforementioned negative current collector 80 can also be welded to the inner wall of the battery can 20.

[0143] Although not shown in the accompanying drawings, the aforementioned negative electrode current collector 80 may have a plurality of protrusions and recesses radially formed on one side. When the aforementioned protrusions and recesses are formed, the negative electrode current collector 80 can be pressed to press the protrusions and recesses into the uncoated portion provided on the negative electrode 12.

[0144] The aforementioned negative electrode current collector 80 can be bonded to the uncoated portion end of the negative electrode 12. The bonding between the uncoated portion of the negative electrode 12 and the negative electrode current collector 80 can be achieved, for example, by laser welding. Laser welding can be performed by melting a portion of the base material of the negative electrode current collector 80, or with solder sandwiched between the negative electrode current collector 80 and the uncoated portion. In this case, preferably, the solder has a lower melting point than both the negative electrode current collector 80 and the uncoated portion. Alternatively, resistance welding, ultrasonic welding, etc., can be used in addition to laser welding, but the welding method is not limited to these methods.

[0145] Although not shown in the accompanying drawings, the aforementioned negative electrode current collector 80 can also be coupled to a bonding surface formed by bending the uncoated portion of the negative electrode 12 in a direction parallel to the negative electrode current collector 80. The bending direction of the uncoated portion of the negative electrode 12 can be, for example, towards the winding center C of the electrode assembly 10. When the uncoated portion of the negative electrode 12 has such a bent shape, the space occupied by the uncoated portion is reduced, thereby increasing the energy density. Furthermore, due to the increased bonding area between the uncoated portion and the negative electrode current collector 80, the bonding force can be improved, and the resistance can be reduced.

[0146] According to one embodiment of the present invention, the secondary battery is a cylindrical secondary battery. In one example, the secondary battery may include a battery can containing the gel roll. The battery can may be cylindrical, with dimensions of 30mm to 55mm in diameter at both ends and 60mm to 120mm in height. For example, the diameter × height of the cylindrical battery can may be 40mm × 60mm, 40mm × 80mm, 40mm × 90mm, or 40mm × 120mm. The secondary battery may be a battery cell.

[0147] Preferably, the cylindrical battery cell can be, for example, a cylindrical battery cell with a shape factor ratio (the value of the diameter of the cylindrical battery cell divided by the height, i.e., defined as the ratio of the diameter Φ relative to the height H) that is approximately greater than 0.4.

[0148] The shape factor indicates the diameter and height of the cylindrical battery cell. According to an embodiment of the present invention, the cylindrical battery cell can be, for example, a 46110 battery cell, a 48750 battery cell, a 48110 battery cell, a 48800 battery cell, a 46800 battery cell, or a 46900 battery cell. In the shape factor values, the first two digits represent the diameter of the battery cell, the next two digits represent the height of the battery cell, and the final digit 0 indicates that the cross-section of the battery cell is circular.

[0149] According to one embodiment of the present invention, the battery cell is a generally cylindrical battery cell, which may be a cylindrical battery cell with a diameter of about 46 mm, a height of about 110 mm, and a shape factor ratio of about 0.418.

[0150] According to another embodiment, the battery cell is a generally cylindrical battery cell, which may be a cylindrical battery cell with a diameter of about 48 mm, a height of about 75 mm, and a shape factor ratio of about 0.640.

[0151] According to another embodiment, the battery cell is a generally cylindrical battery cell, which may be a cylindrical battery cell with a diameter of about 48 mm, a height of about 110 mm, and a shape factor ratio of about 0.418.

[0152] According to another embodiment, the battery cell is a generally cylindrical battery cell, which may be a cylindrical battery cell with a diameter of about 48 mm, a height of about 80 mm, and a shape factor ratio of about 0.600.

[0153] According to another embodiment, the battery cell is a generally cylindrical battery cell, which may be a cylindrical battery cell with a diameter of about 46 mm, a height of about 80 mm, and a shape factor ratio of about 0.575.

[0154] According to another embodiment, the battery cell is a generally cylindrical battery cell, which may be a cylindrical battery cell with a diameter of about 46 mm, a height of about 90 mm, and a shape factor ratio of about 0.511.

[0155] Previously, battery cells with a form factor ratio of approximately 0.4 or less were used. That is, previously, cells such as the 18650 and 21700 were used. The 18650 battery cell has a diameter of approximately 18 mm and a height of approximately 65 mm, with a form factor ratio of 0.277. The 21700 battery cell has a diameter of approximately 21 mm and a height of approximately 70 mm, with a form factor ratio of 0.300.

[0156] Another embodiment of the present invention provides a battery module and a battery pack including a secondary battery according to the above embodiments.

[0157] The secondary battery according to the above embodiment can be used to manufacture the above battery pack.

[0158] Figure 7 It shows including Figure 6 A simplified diagram of the structure of a secondary battery pack.

[0159] Reference Figure 7 According to an embodiment of the present invention, the battery pack 3 includes an assembly electrically connected to secondary batteries 1 and a battery pack housing 2 housing the assembly. The secondary battery 1 is a battery cell according to the above embodiment. In the accompanying drawings, for ease of illustration, components such as busbars, cooling units, and external terminals used to electrically connect the plurality of cylindrical secondary batteries 1 are omitted.

[0160] Another embodiment of the present invention provides a vehicle including a battery pack according to the above embodiment. The battery pack 3 can be mounted on a vehicle. As an example, the vehicle can be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle can be a four-wheeled vehicle or a two-wheeled vehicle.

[0161] Figure 8 It shows including Figure 7 A simplified diagram of the battery pack structure of a car.

[0162] Reference Figure 8 A vehicle 5 according to an embodiment of the present invention includes a battery pack 3 according to an embodiment of the present invention. The vehicle 5 receives power from the battery pack 3 according to an embodiment of the present invention for operation.

[0163] While the present invention has been described above with limited embodiments and accompanying drawings, it is not limited thereto. Those skilled in the art to which this invention pertains should be able to make various modifications and variations within the technical concept and scope equivalent to the claims.

Claims

1. A current collector, characterized in that, include: The main body is conductive; The terminal connection portion is configured to be connected to the electrode terminal; as well as The fuse section connects the main body section and the terminal connection section. The aforementioned fuse portion includes at least one cut-out portion on one side and an insulating portion on at least one side of the aforementioned fuse portion. The aforementioned insulating part is an insulating layer. The aforementioned insulating layer is disposed in a groove formed on at least one side of the aforementioned fuse portion. The groove is formed on the opposite side of the fuse portion having the cut-off portion, and The groove is formed on the opposite side of the fuse portion, corresponding to the cut-off portion.

2. The current collector according to claim 1, characterized in that, The aforementioned insulating layer is an adhesive polymer.

3. The current collector according to claim 2, characterized in that, The aforementioned adhesive polymers include one or more selected from the group consisting of polyimide, polyethylene, polypropylene, polybutylene terephthalate, and perfluoroalkoxy.

4. The current collector according to claim 3, characterized in that, The aforementioned polypropylene includes polypropylene maleic anhydride that can be heated for bonding.

5. A gel roll, characterized in that, include: An electrode assembly having a structure consisting of a positive electrode, a separation membrane, and a negative electrode stacked and wound together; as well as The current collector plate according to any one of claims 1 to 4 is disposed on at least one end side of the electrode assembly.

6. The gel roll according to claim 5, characterized in that, The aforementioned insulating portion is disposed on at least one side of the current collector plate facing the aforementioned electrode assembly.

7. The gel roll according to claim 5, characterized in that, The aforementioned cut-off portion is located on one side of the aforementioned fuse portion, extending from the periphery of the core portion of the aforementioned electrode assembly to the outer corner portion of the aforementioned electrode assembly.

8. A secondary battery, characterized in that, Includes the gel roll as described in claim 5.

9. A battery pack, characterized in that, Includes the secondary battery as described in claim 8.

10. A car, characterized in that, Includes the battery pack as described in claim 9.

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