Current collector plate, jelly roll, secondary battery, battery pack, and automobile

Abstract

The present invention provides a current collecting plate including a conductive body portion; a terminal coupling portion provided to be coupled to an electrode terminal; and a fuse portion connecting the body portion and the terminal coupling portion, the fuse portion including at least one notch portion provided on one surface; and an insulating portion provided on at least one surface of the fuse portion. The current collecting plate, a jelly roll, a secondary battery, a battery pack, and an automobile are also provided.

Description

Technical Field

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2021-0160968, filed with the Korean Intellectual Property Office on November 22, 2021, and all of the content disclosed in the document of the Korean patent application is incorporated herein by reference.

[0002] The present invention relates to a current collector plate, a jelly roll, a secondary battery, a battery pack, and a vehicle.

Background Art

[0003] Secondary batteries, which are highly applicable to a wide range of products and have electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electric drive source.

[0004] Such secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency improvement because they not only have a primary advantage of significantly reducing the use of fossil fuels but also have an advantage of generating no by-products from energy use.

[0005] Currently widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The operating voltage of such a unit secondary battery cell, i.e., a unit battery cell, is about 2.5V to 4.5V. Therefore, when a higher output voltage is required, a plurality of battery cells are connected in series to form a battery pack. Also, depending on the charge and discharge capacity required for the battery pack, a large number of battery cells are connected in parallel to form a battery pack. Therefore, the number and electrical connection form of the battery cells included in the battery pack can be variously set according to the required output voltage and / or charge and discharge capacity.

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a current collector plate, a jelly roll, a secondary battery, a battery pack, and an automobile having a fuse portion with improved short - circuit prevention performance.

Means for Solving the Problems

[0007] One embodiment of the present invention is a main body portion having conductivity; a terminal coupling portion provided to be coupled to an electrode terminal; and a fuse portion connecting the main body portion and the terminal coupling portion; a current collector plate including the fuse portion includes at least one notch portion provided on one surface; and an insulating portion provided on at least one surface of the fuse portion.

[0008] Another embodiment of the present invention provides a jelly roll having a structure in which a positive electrode, a separator, and a negative electrode are laminated and wound; and including the current collector plate according to the above - described embodiment provided on at least one end portion side of the electrode assembly.

[0009] Another embodiment of the present invention provides a secondary battery, a battery pack, and an automobile including the jelly roll according to the above - described embodiment.

Advantages of the Invention

[0010] According to an embodiment of the present invention, it includes a fuse part that can be melted by heat generated during an external short circuit to cut off the current path, and by providing an insulating part on at least the surface facing the electrode assembly of the fuse part, it is possible to prevent the heat generated in the fuse part from being transmitted to the electrode assembly and deforming the electrode assembly or melting the separator. Also, during the process of the fuse part melting, it is possible to prevent problems such as fragments or cuts of the current collector material falling in the direction of the electrode assembly and causing a short circuit.

[0011] As described above, since the heat generated during an external short circuit can be stably processed, the tab structure of the electrode included in the electrode assembly can be formed on the non-coated part of the current collector without coating the electrode active material, so as to increase the current applied to the battery. Thereby, the size of the battery can be increased, and it is possible to realize a high energy density and save costs.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Best Mode for Carrying Out the Invention

[0013] The terms and words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings. Instead, in accordance with the principle that the inventor can appropriately define the concept of the terms in order to best explain his own invention, they should be construed in a meaning and concept that conforms to the technical idea of the present invention.

[0014] Throughout this specification, when a part includes a certain component, unless otherwise specified, this means that other components are not excluded and other components can be further included.

[0015] Also, terms such as “… part” and “device” described in the specification mean a unit that processes at least one function or operation.

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] One embodiment of the present invention is a current collector plate including a conductive main body portion; a terminal coupling portion provided to be coupled to an electrode terminal; and a fuse portion that couples the main body portion and the terminal coupling portion, wherein the fuse portion includes at least one notch portion provided on one surface; and an insulating portion provided on at least one surface of the fuse portion.

[0018] The conductive main body portion is not limited in its structure or material as long as it can electrically connect between the tab portion of the electrode of the secondary battery and the external terminal with the current collector plate. For example, the main body portion may have a circular frame so as to correspond to the form of one end portion of the electrode assembly, the inside may be filled with all conductive materials, and if necessary, a part of the region may have an open form.

[0019] The insulating portion may be provided only on one surface of the fuse portion, or may be provided on two or more surfaces or the entire surface.

[0020] The fuse part is provided with at least one notch part on one surface, and can be melted by the heat generated during an external short circuit to cut off the current path. When the current path is cut off, the voltage of the secondary battery cannot be measured, and an abnormal resistance value may be measured. Therefore, the heat generated in the fuse part can be prevented from being transmitted to the electrode assembly, preventing problems such as deforming the electrode assembly or melting the separator. Also, during the process of the fuse part melting, problems such as fragments or cut pieces of the current collector plate material falling in the direction of the electrode assembly and causing a short circuit can be prevented.

[0021] On the other hand, a conventional current collector plate does not have the notch part. In the case of a secondary battery including this, there is a problem that heat due to heat generation of the positive electrode tab is transmitted to the electrode assembly, causing a phenomenon where the insulator melts.

[0022] FIG. 1 is a drawing showing a schematic structure of a current collector plate according to an embodiment of the present invention.

[0023] Referring to FIG. 1, the current collector plate 100 includes a conductive main body part 110; a terminal coupling part 120 provided to be coupled to the electrode terminal 40; and a fuse part 130 that connects the main body part 110 and the terminal coupling part 120. The fuse part 130 includes at least one notch part 140 provided on one surface; and an insulating part (not shown) provided on at least one surface of the fuse part.

[0024] The structure of the main body part 110 is not limited as long as it can electrically connect between the tab part of the electrode of the secondary battery and the external terminal in the current collector plate 100. As an example, the main body part 110 may have a circular frame, may be entirely filled with a conductive material inside, and may have an open form in a partial region if necessary.

[0025] The fuse part 130 is not limited in its structure, material, or number as long as it connects the main body part 110 and the terminal connection part 120. As an example, the fuse part 130 may connect the main body part 110 and the terminal connection part 120 in multiple directions and in multiple numbers. The number of connections is not limited, but at least in one part, the main body part 110 and the terminal connection part 120 can be connected.

[0026] Referring to FIG. 1, the notch part 140 may mean a part where a groove is engraved in a V shape in the fuse part 130. By providing at least one notch part 140 on one surface of the fuse part 130, it can melt due to the heat generated during an external short circuit and cut off the current path.

[0027] Also, by providing an insulating part on at least the surface of the fuse part 130 facing the electrode assembly, the heat generated in the fuse part 130 can be prevented from being transmitted to the electrode assembly, which can prevent problems such as deforming the electrode assembly or melting the separator. During the process of the fuse part 130 melting, problems such as fragments or cuts of the current collector plate 100 material falling in the direction of the electrode assembly and causing a short circuit can also be prevented.

[0028] One embodiment of the present invention provides a current collector plate in which an insulating part (not shown) is provided on the surface opposite to the one surface of the fuse part 130 provided with the notch part 140.

[0029] A notch part 140 may be provided on one surface of the fuse part 130, and an insulating part may be provided on the surface opposite to the one surface provided with the notch part 140. As an example, the surface opposite to the one surface of the fuse part 130 provided with the notch part 140 may be the surface facing the electrode assembly.

[0030] The fuse part 130 is provided with at least one notch part 140 on one side, and can be melted by the heat generated during an external short circuit to cut off the current path. By providing an insulating part on the surface opposite to the notch part 140, the heat generated in the fuse part 130 is prevented from being transmitted to the electrode assembly, preventing problems such as deforming the electrode assembly or melting the separator, and also preventing problems such as fragments or cuts falling in the direction of the electrode assembly and causing a short circuit.

[0031] According to an embodiment of the present invention, the insulating part is an insulating tape.

[0032] Figure 2 is a drawing showing a configuration in which the insulating part is an insulating tape in a current collector plate according to an embodiment of the present invention.

[0033] Referring to Figure 2, this illustrates a structure in which the insulating tape 151 is attached to the current collector plate 100. According to an example, the insulating tape 151 may be attached in a state where the fuse part 130 is erected perpendicular to the plate surface of the current collector plate 100.

[0034] The insulating tape 151 may be attached to one surface or the opposite surface of the fuse part 130 provided with the notch part 140, or may be attached to the upper surface or the opposite surface of the notch part 140.

[0035] According to an embodiment of the present invention, the insulating part is an insulating layer. At this time, the insulating layer may have a structure provided in a groove part provided on at least one surface of the fuse part.

[0036] According to an embodiment of the present invention, the groove part is provided on the surface opposite to the one surface of the fuse part provided with the notch part, and the groove part may be provided at a position corresponding to the notch part on the surface opposite to the one surface of the fuse part provided with the notch part.

[0037] Figure 3 is a drawing showing a configuration in which the insulating part is an insulating layer in a current collector plate according to an embodiment of the present invention.

[0038] Referring to FIG. 3, the structure in which the insulating layer 152 is provided in the groove portion 160 provided on one surface of the fuse portion 130 is illustrated. The groove portion 160 may be formed by applying a step using a forging method.

[0039] The groove portion 160 may be provided on the surface of the fuse portion 130 opposite to the surface on which the notch portion 140 is provided. The groove portion 160 may be provided at a position corresponding to the notch portion 140 on the surface of the fuse portion 130 opposite to the surface on which the notch portion 140 is provided. As an example, the groove portion 160 may be provided at a position where the notch portion 140 and the groove portion 160 face each other at the end surface of the fuse portion 130.

[0040] When viewed from the side cross-section of the fuse portion 130, based on the overall thickness of the fuse portion, the notch portion 140 may be formed, and the thickness of the groove portion 160 may be formed to be equal to or less than the thickness of the remaining fuse portion 130.

[0041] When the insulating layer 152 is provided in the groove portion 160 provided at the position, heat generated in the fuse portion 130 can be prevented from being transmitted to the electrode assembly, thereby preventing problems such as deforming the electrode assembly or melting the separator. In the process of melting the fuse portion 130, problems such as fragments or chips of the current collector plate 100 material falling in the direction of the electrode assembly and causing a short circuit can also be prevented.

[0042] According to an embodiment of the present invention, the materials of the insulating tape and the insulating layer are not particularly limited as long as they can perform an insulating role.

[0043] According to an embodiment of the present invention, the insulating layer is an adhesive polymer, and the adhesive polymer includes one or more selected from the group consisting of polyimide (PI), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), and perfluoroalkoxy alkane (PFA).

[0044] When including the above materials, the insulating layer can have heat resistance and chemical resistance within the secondary battery. Also, it is possible to prevent the problem that heat generated in the fuse part is transmitted to the electrode assembly to deform the electrode assembly or melt the separator, and it is also possible to prevent the problem that fragments or cuts of the current collector plate material fall in the direction of the electrode assembly during the process of the fuse part melting, resulting in a short circuit.

[0045] According to an embodiment of the present invention, the polypropylene (PP) includes maleic anhydride polypropylene (PP-MAH) that can be adhered by applying heat.

[0046] When including the above compound, the adhesive polymer can be adhered by applying heat and can have heat resistance and chemical resistance within the secondary battery. Also, due to the heat generated in the fuse part, the adhesive polymer can form an insulating layer, thereby preventing the problem that it is transmitted to the electrode assembly to deform the electrode assembly or melt the separator, and it is also possible to prevent the problem that fragments or cuts of the current collector plate material fall in the direction of the electrode assembly during the process of the fuse part melting, resulting in a short circuit.

[0047] An additional embodiment of the present invention provides a jelly roll having a structure in which a positive electrode, a separator, and a negative electrode are laminated and wound; and including a current collector plate according to the above-described embodiment provided on at least one end side of the electrode assembly.

[0048] According to an embodiment of the present invention, it is preferable that the insulating portion is provided on at least the surface of the current collector facing the electrode assembly. By providing the insulating portion on at least the surface facing the electrode assembly, when the fuse portion melts due to heat generation caused by an external short circuit, it is possible to prevent the heat and fragments or cuts of the current collector plate from affecting the electrode assembly.

[0049] According to an embodiment of the present invention, the notch portion is provided in a region from around the core portion of the electrode assembly to the outer portion of the electrode assembly on one surface of the fuse portion.

[0050] The notch portion may be provided at any position on one surface of the fuse portion without being restricted. Preferably, the notch portion may be provided in a region from around the core portion of the electrode assembly to the outer portion of the electrode assembly on one surface of the fuse portion, and by providing the insulating portion at a position corresponding to this region, when the fuse portion melts due to heat generation caused by an external short circuit, it is possible to prevent the heat and fragments or cuts of the current collector plate from affecting the electrode assembly, and further improve safety.

[0051] FIG. 4 is a drawing schematically showing the position where the notch portion is provided in the current collector plate included in the jelly roll according to an embodiment of the present invention.

[0052] Referring to FIG. 4, the notch portion 140L is provided in a region from around the core portion CR of the electrode assembly to the outer portion O of the electrode assembly on one surface of the fuse portion 130. When the fuse portion melts due to heat generation caused by an external short circuit, the insulating portion provided at the position corresponding to the notch portion can prevent the heat and fragments or cuts of the current collector plate from affecting the electrode assembly.

[0053] Another embodiment of the present invention provides a secondary battery including the jelly roll according to the above-described embodiment.

[0054] FIG. 5 is a drawing showing a schematic configuration of a secondary battery according to an embodiment of the present invention, and FIG. 6 is a longitudinal sectional view of the secondary battery of FIG. 5.

[0055] Referring to FIGS. 5 and 6, the secondary battery 1 according to an embodiment of the present invention includes an electrode assembly 10, a battery can 20, a sealing body 30, and an electrode terminal 40. The jelly roll may include the electrode assembly 10 and a positive current collector 50. 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 in addition to the above components.

[0056] The current collector according to an embodiment of the present invention may be the positive current collector 50.

[0057] Referring to FIGS. 5 and 6, the electrode assembly 10 includes a positive electrode 11, a negative electrode 12, and a separator interposed between the positive electrode 11 and the negative electrode 12.

[0058] The positive electrode 11 and the negative electrode 12 may have a sheet shape. The electrode assembly 10 may have, for example, a jellyroll shape. That is, the electrode assembly 10 can be manufactured by winding a laminate formed by sequentially laminating at least once a positive electrode 11, a separator, a negative electrode 12, and a separator with a winding core portion C as a reference. In this case, a separator may be further provided on the outer peripheral surface of the electrode assembly 10 for insulation from the battery can 20.

[0059] The positive electrode 11 and the negative electrode 12 may include a plain portion where the active material layer is not coated at the long side end portion. The positive electrode 11 and the negative electrode 12 may include an active material portion where the active material layer is coated in a region excluding the plain portion.

[0060] Specifically, the positive electrode 11 includes a positive electrode current collector and a positive electrode active material coated on one or both surfaces of the positive electrode current collector. The region where the positive electrode active material is coated on the positive electrode current collector is referred to as the active material portion provided in the positive electrode 11. There may be a plain portion where no positive electrode active material is coated at one end portion in the width direction (the direction aligned with the Z-axis) of the positive electrode current collector. At least a part of the plain portion is used as an electrode tab by itself. That is, the plain portion functions as the plain portion provided in the positive electrode 11. The plain portion provided in the positive electrode 11 is provided at the upper part in the height direction (the direction aligned with the Z-axis) of the electrode assembly 10 housed in the battery can 20.

[0061] The negative electrode 12 includes a negative electrode current collector and a negative electrode active material coated on one or both surfaces of the negative electrode current collector. The region where the negative electrode active material is coated on the negative electrode current collector is referred to as the active material portion provided in the negative electrode 12. There may be a plain portion where no negative electrode active material is coated at the other end portion in the width direction (the direction aligned with the Z-axis) of the negative electrode current collector. At least a part of the plain portion is used as an electrode tab by itself. That is, the plain portion functions as the plain portion provided in the negative electrode 12. The plain portion provided in the negative electrode 12 is provided at the lower part in the height direction (the direction aligned with the Z-axis) of the electrode assembly 10 housed in the battery can 20.

[0062] The plain portion provided in the positive electrode 11 and the plain portion provided in the negative electrode 12 may be in a form protruding in opposite directions. For example, referring to FIG. 6, the plain portion provided in the positive electrode 11 may protrude toward the upper part in the height direction (the direction aligned with the Z-axis) of the electrode assembly 10, and the plain portion provided in the negative electrode 12 may protrude toward the lower part in the height direction (the direction aligned with the Z-axis) of the electrode assembly 10. Thereby, the plain portion provided in the positive electrode and the plain portion provided in the negative electrode may be in a form extending and protruding in opposite directions along the width direction of the electrode assembly 10, that is, the height direction (the direction aligned with the Z-axis) of the secondary battery 1.

[0063] In the present 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 used without limitation as long as they are active materials known in the art.

[0064] As non-limiting examples of the positive electrode active material, ordinary positive electrode active materials that can be used for the positive electrode of conventional electrochemical elements can be used. In particular, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or a lithium composite oxide combining these may be used.

[0065] In one example, the positive electrode active material may contain an alkali metal compound represented by the general chemical formula A[A x M y O 2+z (A contains at least one or more elements of Li, Na, and K; M contains at least one or more elements 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 x, y, z, and the components contained in M are selected so that the compound maintains electrical neutrality).

[0066] In another example, the positive electrode active material may be an alkali metal compound xLiM 1 O 2 -(1 - x)Li 2 M 2 O 3 (M 1 contains at least one or more elements having an average oxidation state of 3; M 2 contains at least one or more elements having an average oxidation state of 4; 0≦x≦1).

[0067] In still another example, the positive electrode active material has the general chemical formula Li a M 1 x Fe 1-x M 2 y P 1-y M 3z O 4-z (M 1 contains at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg and Al; M 2 contains 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 contains a halogen group element selectively containing F; 0 < a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y < 1, 0 ≤ z < 1; a, x, y, z, M 1 、M 2 、and M 3 The stoichiometric coefficients of the components contained in are selected so that the compound maintains electrical neutrality), or Li 3 M 2 (PO 4 ) 3 [M contains at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al] may be a lithium metal phosphate represented by.

[0068] Preferably, the positive electrode active material may contain primary particles and / or secondary particles in which the primary particles are aggregated.

[0069] As a non-limiting example of the negative electrode active material, a normal negative electrode active material that can be used for the negative electrode of a conventional electrochemical element can be used. In particular, a lithium adsorption material such as lithium metal or a lithium alloy, carbon, petroleum coke, activated carbon, graphite or other carbon materials can be used.

[0070] In one example, the negative electrode active material may be made of a carbon material, lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, etc. Metal oxides such as TiO 2 、SnO 2 with a potential of less than 2V can also be used as the negative electrode active material. As the carbon material, any of low-crystalline carbon and highly crystalline carbon can be used.

[0071] The separator may be a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as a homopolymer of ethylene, a homopolymer of propylene, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer, used alone or laminated. As another example, the separator may be an ordinary porous nonwoven fabric, for example, a nonwoven fabric made of high melting point glass fibers, polyethylene terephthalate fibers, etc.

[0072] The surface of at least one side of the separator may include a coating layer of inorganic particles. Also, the separator itself may be composed of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure in which they are bonded to a binder so that an interstitial volume exists between adjacent particles.

[0073] The inorganic particles may be composed of an inorganic substance having a dielectric constant of 5 or more. As a non-limiting example, the inorganic particles may be Pb(Zr,Ti)O 3 (PZT), Pb 1-x La x Zr 1-y Ti y O 3 (PLZT), PB(Mg 3 Nb 2 / 3 )O 3 -PbTiO 3 (PMN-PT), BaTiO 3 , hafnia (HfO 2 ), SrTiO 3 , TiO 2 , Al 2 O 3 , ZrO 2 , SnO 2 , CeO 2 , MgO, CaO, ZnO and Y 2 O 3 and may contain at least one or more substances selected from the group consisting of.

[0074] The electrolyte is A+ B - may be a salt having a structure such as this. Here, A + is Li + , Na + , K + and includes ions composed of alkali metal cations such as these or combinations thereof. And B - is F - , Cl - , Br - , I - , NO 3 - , N(CN) 2- , BF 4 - , ClO 4 - , AlO 4 - , AlCl 4 - , PF 6 - , SbF 6 - , AsF 6 - , BF 2 C 2 O 4 - , BC 4 O 8 - , (CF 3 ) 2 PF 4 - , (CF 3 ) 3 PF 3 - , (CF 3 ) 4 PF 2 - , (CF 3 ) 5 PF - , (CF 3 ) 6 P - , CF 3 SO 3 - , C 4 F 9 SO 3 - , CF 3 CF 2 SO 3- and (CF 3 SO 2 ) 2 N - and (FSO 2 ) 2 N - and CF 3 CF 2 (CF 3 ) 2 CO - and (CF 3 SO 2 ) 2 CH - and (SF 5 ) 3 C - and (CF 3 SO 2 ) 3 C - and CF 3 (CF 2 ) 7 SO 3 - and CF 3 CO 2 - and CH 3 CO 2 - and SCN - and (CF 3 CF 2 SO 2 ) 2 N - and contains any one or more anions selected from the group consisting of.

[0075] The electrolyte may also be used after being dissolved in an organic solvent. Examples of the organic solvent include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or a mixture thereof.

[0076] Referring to FIGS. 5 and 6, the battery can 20 is a substantially cylindrical container having an opening formed at the lower end, and is made of a conductive material such as metal. The material of the battery can 20 may be, for example, aluminum. The bottom of the battery can 20 having the opening is referred to as an opened end. The side surface (outer peripheral surface) and the upper surface of the battery can 20 may be integrally formed. The upper surface of the battery can 20 (the surface arranged in the X-Y plane) has a substantially flat shape. The upper surface located on the opposite side of the opened end is referred to as a closed end. The battery can 20 houses the electrode assembly 10 through the opening formed below, and also houses the electrolyte together.

[0077] The battery can 20 is electrically connected to the electrode assembly 10. For example, the battery can may be electrically connected to the negative electrode 12 of the electrode assembly 10. In this case, the battery can 20 may have the same polarity as the negative electrode 12.

[0078] Referring to FIG. 6, the battery can 20 may include a beading portion 21 and a caulking portion 22 formed at its lower end. The beading portion 21 is located below the electrode assembly 10. The beading portion 21 is formed by press-fitting around the outer peripheral surface of the battery can 20. The beading portion 21 can function as a support portion where the sealing body 30 is seated, so that the electrode assembly 10 having a size generally corresponding to the width of the battery can 20 does not escape through the open portion formed at the lower end of the battery can 20.

[0079] The caulking portion 22 is formed below the beading portion 21. The caulking portion 22 has a form that extends and bends so as to surround the outer peripheral surface of the sealing body 30 disposed below the beading portion 21 and a part of the lower surface of the sealing body 30.

[0080] However, the present invention does not exclude the case where the battery can 20 does not include such a beading portion 21 and / or caulking portion 22. That is, in the present invention, when the battery can 20 does not include the beading portion 21 and / or caulking portion 22, the fixing of the electrode assembly 10 and / or the sealing of the battery can 20 can be realized, for example, by additional application of a component that can function as a stopper for the electrode assembly 10. Further, when the secondary battery 1 of the present invention includes the sealing body 30, the fixing of the electrode assembly 10 and / or the sealing of the battery can 20 can be realized, for example, by additional application of a structure on which the sealing body 30 can be seated and / or welding between the battery can 20 and the sealing body 30. That is, the sealing body can seal the open end of the battery can.

[0081] Referring to FIG. 6, the sealing body 30 may be made of, for example, a metal material in order to ensure rigidity. The sealing body 30 can cover the open end formed at the lower end of the battery can 20. That is, the sealing body 30 forms the lower surface of the secondary battery 1.

[0082] In the secondary battery 1 of the present invention, even when the sealing body 30 is made of a conductive metal material, it has no polarity. Having no polarity may mean that the sealing body 30 is electrically insulated from the battery can 20 and the electrode terminal 40.

[0083] Therefore, the sealing body 30 does not function as the electrode terminal 40, that is, the positive electrode terminal or the negative electrode terminal. Thus, the sealing body 30 does not need to be electrically connected to the electrode assembly 10 and the battery can 20, and its material does not necessarily have to be a conductive metal.

[0084] When the battery can 20 of the present invention includes a beading portion 21, the sealing body 30 may be seated on the beading portion 21 formed on the battery can 20. Further, when the battery can 20 of the present invention includes a caulking portion 22, the sealing body 30 may be fixed by the caulking portion 22. A sealing gasket 90 may be interposed between the sealing body 30 and the caulking portion 22 of the battery can 20 to ensure the airtightness of the battery can 20. On the other hand, as described above, the battery can 20 of the present invention may not include the beading portion 21 and / or the caulking portion 22. In this case, the sealing gasket 90 may be interposed between the sealing body 30 and a fixed structure provided on the open portion side of the battery can 20 to ensure the airtightness of the battery can 20.

[0085] Referring to FIGS. 5 and 6, the electrode terminal 40 may be electrically connected to the other one of the positive electrode 11 and the negative electrode 12. That is, the electrode terminal 40 may have a polarity opposite to that of the battery can 20. For example, the electrode terminal 40 may be electrically connected to the positive electrode 11 of the electrode assembly 10. And the surface of the electrode terminal 40 may be exposed to the outside.

[0086] The electrode terminal 40 may be made of a conductive metal material. The electrode terminal 40 can penetrate, for example, substantially the center of the closed end formed at the upper end of the battery can 20. A part of the electrode terminal 40 may be exposed above the battery can 20, and the remaining part may be located inside the battery can 20. The electrode terminal 40 may be fixed, for example, by riveting on the inner surface of the closed end of the battery can 20. The electrode terminal 40 can penetrate the insulating member 60 and be coupled to a plain part provided on the positive current collector plate 50 or the positive electrode 11. In this case, the electrode terminal 40 may have a first polarity.

[0087] Therefore, the electrode terminal 40 can function as a positive electrode terminal in the secondary battery 1 of the present invention. When the electrode terminal 40 has the first polarity in this way, the electrode terminal 40 is electrically insulated from the battery can 20 having the second polarity. The electrical insulation between the electrode terminal 40 and the battery can 20 can be realized in various ways.

[0088] As another example, insulation can be achieved by interposing an insulating gasket 70 as described later between the electrode terminal 40 and the battery can 20. In contrast, insulation can be achieved by forming an insulating coating layer on a part of the electrode terminal 40. Alternatively, a method of structurally and firmly fixing the electrode terminal 40 so that contact between the electrode terminal 40 and the battery can 20 becomes impossible may be applied. Alternatively, a plurality of the above-described methods may be applied together.

[0089] Referring to FIG. 6, the positive current collector plate 50 may be coupled to the upper part of the electrode assembly 10. For example, the positive current collector plate 50 may be coupled to a plain part provided on the positive electrode 11 above the electrode assembly 10. The positive current collector plate 50 may be made of a conductive metal material. Although not shown, the positive current collector plate 50 may have a plurality of irregularities formed radially on its lower surface.

[0090] When the unevenness is formed, the positive electrode current collector plate 50 can be pressed so that the unevenness is press-fitted into the plain portion provided in the positive electrode 11.

[0091] The secondary battery 1 according to another embodiment of the present invention may not include the positive electrode current collector plate 50. In this case, the plain portion provided in the positive electrode 11 can be directly electrically connected to the electrode terminal 40.

[0092] Referring to FIG. 6, the positive electrode current collector plate 50 can be coupled to an end portion of the plain portion provided in the positive electrode 11. The coupling between the plain portion provided in the positive electrode 11 and the positive electrode current collector plate 50 may be performed, for example, by laser welding. The laser welding may be performed in a manner of partially melting the base material of the positive electrode current collector plate 50, or may be performed with a solder for welding interposed between the positive electrode current collector plate 50 and the plain portion. In this case, the solder preferably has a melting point lower than that of the positive electrode current collector plate 50 and the plain portion. On the other hand, in addition to laser welding, resistance welding, ultrasonic welding, etc. are possible, but the welding method is not limited thereto.

[0093] Referring to FIG. 6, the insulating member 60 may be provided between the upper end of the electrode assembly 10 and the inner surface of the battery can 20 or between the positive electrode current collector plate 50 coupled to the upper portion of the electrode assembly 10 and the inner surface of the battery can 20. The insulating member 60 prevents contact between the plain portion provided in the positive electrode 11 and the battery can 20 and / or contact between the positive electrode current collector plate 50 and the battery can 20. That is, the insulating member 60 is housed inside the battery can 20 and is configured to block the electrical connection between the plain portion provided in the positive electrode 11 and the battery can 20. Therefore, the insulating member 60 may be made of a material having insulating performance. For example, the insulating member 60 may include a polymer material.

[0094] Referring to FIGS. 5 and 6, the insulating gasket 70 is interposed between the battery can 20 and the electrode terminal 40 to prevent the battery can 20 and the electrode terminal 40 having opposite polarities from contacting each other. That is, the insulating gasket 70 cuts off the electrical connection between the battery can 20 and the electrode terminal 40. Thereby, the upper surface of the battery can 20 having a substantially flat shape can function as the terminal of the negative electrode 12 of the secondary battery 1.

[0095] Referring to FIG. 6, the negative electrode current collector 80 may be coupled to the lower portion of the electrode assembly 10. The negative electrode current collector 80 may be made of a conductive metal material. The negative electrode current collector 80 may be connected to the plain portion provided on the negative electrode 12. Further, the negative electrode current collector 80 may be electrically connected to the battery can 20. As shown in FIG. 2, the negative electrode current collector 80 may be interposed and fixed between the inner surface of the battery can 20 and the sealing gasket 90. On the contrary, the negative electrode current collector 80 may be welded to the inner wall surface of the battery can 20.

[0096] Although not shown, the negative electrode current collector 80 may be provided with a plurality of irregularities formed radially on one surface thereof. When the irregularities are formed, the negative electrode current collector 80 may be pressed and the irregularities may be press-fitted into the plain portion provided on the negative electrode 12.

[0097] The negative electrode current collector 80 may be coupled to the end of the plain portion provided on the negative electrode 12. The connection between the plain portion provided on the negative electrode 12 and the negative electrode current collector 80 may be performed, for example, by laser welding. The laser welding may be performed in a manner of partially melting the base material of the negative electrode current collector 80, or may be performed with a solder for welding interposed between the negative electrode current collector 80 and the plain portion. In this case, the solder preferably has a lower melting point than the negative electrode current collector 80 and the plain portion. On the other hand, in addition to laser welding, resistance welding, ultrasonic welding, etc. are possible, but the welding method is not limited thereto.

[0098] Although not shown, the negative electrode current collector 80 may be coupled to a bonding surface formed by bending an end of a plain portion provided in the negative electrode 12 in a direction parallel to the negative electrode current collector 80. The bending direction of the plain portion provided in the negative electrode 12 may be, for example, a direction toward the winding center C of the electrode assembly 10. When the plain portion provided in the negative electrode 12 has such a bent form, the space occupied by the plain portion is reduced, which can lead to an improvement in energy density. Also, an increase in the bonding area between the plain portion and the negative electrode current collector 80 can bring about an improvement in bonding force and a resistance reduction effect.

[0099] 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 in which the jelly roll is housed. The battery can may be cylindrical, and its size may be such that the circular diameter at both ends is 30 mm to 55 mm and the height is 60 mm to 120 mm. For example, the circular diameter × height of the cylindrical battery can may be 40 mm × 60 mm, 40 mm × 80 mm, 40 mm × 90 mm, or 40 mm × 120 mm. The secondary battery may be a battery cell.

[0100] Preferably, the cylindrical battery cell may be, for example, a cylindrical battery cell having a form factor ratio (a value obtained by dividing the diameter of the cylindrical battery cell by its height, that is, a ratio of height H to diameter Φ) greater than approximately 0.4.

[0101] Here, the form factor means a value indicating the diameter and height of the cylindrical battery cell. The cylindrical battery cell according to one embodiment of the present invention may be, for example, a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, a 46800 cell, or a 46900 cell. In the numerical value indicating the form factor, the first two digits represent the diameter of the cell, the next two digits represent the height of the cell, and the last digit 0 indicates that the cross-section of the cell is circular.

[0102] A battery cell according to an embodiment of the present invention may be a substantially cylindrical cell with a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0103] A battery cell according to another embodiment may be a substantially cylindrical cell with a diameter of approximately 48 mm, a height of approximately 75 mm, and a form factor ratio of 0.640.

[0104] A battery cell according to yet another embodiment may be a substantially cylindrical cell with a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0105] A battery cell according to yet another embodiment may be a substantially cylindrical cell with a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of 0.600.

[0106] A battery cell according to yet another embodiment may be a substantially cylindrical cell with a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of 0.575.

[0107] A battery cell according to yet another embodiment may be a substantially cylindrical cell with a diameter of approximately 46 mm, a height of approximately 90 mm, and a form factor ratio of 0.511.

[0108] Conventionally, battery cells with a form factor ratio of approximately 0.4 or less have been used. That is, conventionally, for example, 18650 cells, 21700 cells, etc. have been used. In the case of 18650 cells, the diameter is approximately 18 mm, the height is approximately 65 mm, and the form factor ratio is 0.277. In the case of 21700 cells, the diameter is approximately 21 mm, the height is approximately 70 mm, and the form factor ratio is 0.300.

[0109] Another embodiment of the present invention provides a battery module and a battery pack including a secondary battery according to the above-described embodiment.

[0110] The secondary battery according to the above-described embodiment may be used to manufacture the battery pack.

[0111] FIG. 7 is a drawing showing a schematic configuration of a battery pack including the secondary battery of FIG. 6.

[0112] Referring to FIG. 7, a battery pack 3 according to an embodiment of the present invention includes an assembly in which secondary batteries 1 are electrically connected, and a pack housing 2 that houses the assembly. The secondary battery 1 is a battery cell according to the above-described embodiment. In the drawing, for the sake of illustration, illustration of components such as a bus bar, a cooling unit, and an external terminal for electrical connection of the cylindrical secondary battery 1 is omitted.

[0113] Another embodiment of the present invention provides an automobile including the battery pack according to the above-described embodiment. The battery pack 3 can be mounted on an automobile. The automobile may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The automobile includes a four-wheel vehicle or a two-wheel vehicle.

[0114] FIG. 8 is a drawing showing a schematic configuration of an automobile including the battery pack of FIG. 7.

[0115] Referring to FIG. 8, an automobile 5 according to an embodiment of the present invention includes a battery pack 3 according to an embodiment of the present invention. The automobile 5 operates by receiving power from the battery pack 3 according to an embodiment of the present invention.

[0116] As described above, the present invention has been described with reference to limited embodiments and drawings. However, the present invention is not limited thereby, and it goes without saying that various modifications and variations can be made within the equivalent scope of the technical idea and claims of the present invention by those having ordinary knowledge in the technical field to which the present invention pertains.

Explanation of Reference Numerals

[0117] 1 ··· Secondary battery 2 ··· Pack housing 3 ··· Battery pack 5 ··· Automobile 10 ··· Electrode assembly 10’ ··· Jelly roll C ··· Winding core part CR ··· Around the winding core part O ··· Outer part 11 ··· Positive electrode 12 ··· Negative electrode 13 ··· Separator 20 ··· Battery can 21 ··· Beading part 22 ··· Crimping part 30 ··· Sealing body 40 ··· Electrode terminal 50 ··· Positive current collector 60 ··· Insulator 70 ··· Insulating gasket 80 ··· Negative current collector 90 ··· Sealing gasket 100 ··· Current collector 110 ··· Body part 120 ··· Terminal connection part 130 ··· Fuse part 140 ··· Notch part 140L ··· Notch part equipped area 150 ··· Insulating part 151 ··· Insulating tape 152 ··· Insulating layer 160 ··· Groove part

Claims

1. A main body portion having conductivity; A terminal coupling portion provided so as to be coupled to an electrode terminal; and A fuse portion connecting the main body portion and the terminal coupling portion A current collector plate including, The fuse portion includes at least one notch portion provided on one surface; and an insulating portion provided on at least one surface of the fuse portion, A groove portion is formed on a surface opposite to the one surface of the fuse portion provided with the notch portion, The insulating portion is disposed in the groove portion, The groove portion is formed at a position corresponding to the notch portion, a current collector plate.

2. The current collector plate according to claim 1, wherein the insulating portion is an insulating tape.

3. The current collector plate according to claim 1, wherein the insulating portion is an insulating layer.

4. The current collector plate according to claim 3, wherein the insulating layer is an adhesive polymer.

5. The adhesive polymer includes one or more selected from the group consisting of polyimide (PI), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), and perfluoroalkoxy alkane (PFA). The current collector plate according to claim 4.

6. The polypropylene (PP) in the current collector plate according to claim 5 includes maleic anhydride polypropylene (PP-MAH) that can be adhered by applying heat.

7. An electrode assembly having a structure in which a positive electrode, a separator, and a negative electrode are laminated and wound; and The current collector plate according to any one of claims 1 to 6 provided on at least one end side of the electrode assembly A jelly roll including.

8. The jelly roll according to claim 7, wherein the insulating portion is provided on at least a surface of the current collector plate facing the electrode assembly.

9. The jelly roll according to claim 7, wherein the notch portion is provided in a region from around the winding core portion of the electrode assembly to the outer portion of the electrode assembly on one surface of the fuse portion.

10. A secondary battery including the jelly roll according to claim 7.

11. A battery pack including the secondary battery according to claim 10.

12. An automobile including the battery pack according to claim 11.

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