Secondary battery

Abstract

The present invention relates to a secondary battery in which a coating is formed by coating the surface of the outermost separator of an electrode assembly with a heat-resistant material, thereby preventing heat generated by abnormal heating of the battery cell from being transmitted to the outside through the case, or preventing external heat from being transmitted to the inside of the battery cell. For example, the present invention provides a secondary battery including: an electrode assembly including a first electrode plate, a second electrode plate, and a separator interposed between the first electrode plate and the second electrode plate, in which a first electrode tab, which is a non-coated portion of the first electrode plate, protrudes in one direction; a case receiving the electrode assembly; a cover plate for sealing the upper end portion of the case; and a first terminal portion electrically connected to the first electrode plate of the electrode assembly, the first terminal portion being exposed to the outside of the cover plate. The separator is located at the outermost portion of the electrode assembly, and a coating is formed by coating the surface of the outermost separator with a heat-resistant material.

Description

Technical Field

[0001] Various embodiments of the present invention relate to secondary batteries. Background Technology

[0002] A secondary battery is an energy storage system that offers superior energy density for storing electrical energy in the form of chemical energy. Unlike non-rechargeable primary batteries, secondary batteries are rechargeable and widely used in IT devices such as smartphones, mobile phones, laptops, and tablets. Recently, there has been increased interest in electric vehicles to prevent environmental pollution, and accordingly, electric vehicles are adopting high-capacity secondary batteries. These secondary batteries require characteristics such as high energy density, high output, and stability.

[0003] The information disclosed in this background section is only intended to enhance the understanding of the background of the invention, and therefore may contain information that does not constitute prior art. Summary of the Invention

[0004] Technical issues

[0005] The present invention provides a secondary battery in which a coating is formed by coating the surface of the outermost separator of the electrode assembly with a heat-resistant material, thereby preventing heat generated by abnormal heating of the battery cell from being transferred to the outside through the casing, or preventing external heat from being transferred to the inside of the battery cell.

[0006] Solution

[0007] A secondary battery according to an embodiment of the present invention includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator inserted between the first electrode plate and the second electrode plate, wherein a first electrode terminal piece, which is an uncoated portion of the first electrode plate, extends in one direction; a housing receiving the electrode assembly; a cover plate for sealing the upper end of the housing; and a first terminal portion electrically connected to the first electrode plate of the electrode assembly, the first terminal portion being exposed outside the cover plate, the separator being located at the outermost edge of the electrode assembly, and a coating is formed by coating the surface of the outermost separator with a heat-resistant material.

[0008] Electrode fittings can be formed by winding a stack of the first electrode plate, the partition, and the second electrode plate into the shape of a jelly roll, and the second electrode tab, which is the uncoated part of the second electrode plate, can extend in the opposite direction to the first electrode tab.

[0009] Electrode fittings can be formed in a stacked form, wherein a first electrode plate, a partition, a second electrode plate, and a partition are stacked in sequence, and a second electrode terminal piece, which is the uncoated part of the second electrode plate, can extend in the opposite direction to the first electrode terminal piece.

[0010] The coating can be applied to cover all the outer surfaces of the partition, and the first electrode terminal and the second electrode terminal can extend from the coating toward both sides in the longitudinal direction of the electrode fitting, respectively.

[0011] The coating can be formed such that multiple holes are arranged in a dot array or matrix, and the partition can be exposed to the outside through multiple holes.

[0012] The coating can be applied as a septum covering the long side of the electrode fitting, and the septum can be exposed to the outside through the upper and lower surfaces of the electrode fitting.

[0013] The coating can be formed such that multiple holes are arranged in a dot array or matrix, and the partition can be exposed to the outside through multiple holes.

[0014] The coating can be applied to the inner surface of the outermost partition.

[0015] The first electrode connector can be connected at the first terminal portion to the first current collector plate housed inside the housing, and the second electrode connector can be connected at the second terminal portion exposed outside the cover plate to the second current collector plate housed inside the housing.

[0016] The coating can be applied to cover the fixing strip and the first and second current collector plates, the fixing strip being used to fix the outermost partition to the outermost surface of the electrode assembly.

[0017] The separator may be a porous membrane comprising at least one selected from the group consisting of: polystyrene (PS), polyethylene (PE), polypropylene (PP), polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyurethane (PU), polymethylpentene (PMP), polyethylene terephthalate (PET), polycarbonate (PC), polyester, polyvinyl alcohol (PVA), polyacrylonitrile (PAN), silicone acrylate rubber, ethylene-methyl acrylate copolymer, polymethylene oxide (PMO), polymethyl methacrylate (PMMA), polyethylene oxide (PEO), polyamide (PA), polyamide-imide (PAI), polysulfone (PSF), polyethyl sulfone (PES), polyphenylene sulfide (PPS), polyarylate (PAR), polyimide (PI), aromatic polyamide (PA), cellulose, modified cellulose, melamine resins, and phenolic resins.

[0018] The coating is a single substance or a mixture of two or more substances selected from the group consisting of: polyimide, polybutylene terephthalate (PBT), polyamide-imide (PAI), perfluoroalkoxy (PFA), polysulfone (PSF), polyarylsulfone (PAS), polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), and polyvinyl naphthalene (PEN), which are liquid polymer materials with strong heat resistance.

[0019] Beneficial effects of this disclosure

[0020] In a secondary battery according to an embodiment of the present invention, a coating of heat-resistant material is applied to the surface of the outermost separator of the electrode fitting having heat-resistant material, thereby preventing heat generated by abnormal heating of the battery cell from being transferred to the outside through the casing, or preventing external heat from being transferred to the inside of the battery cell. Attached Figure Description

[0021] Figure 1 Perspective views illustrating various embodiments of a secondary battery according to the present invention.

[0022] Figure 2 For along Figure 1 The image shows a cross-sectional view of the secondary battery taken from line 2-2.

[0023] Figures 3a to 3c for Figure 1 Examples of exploded perspective views, perspective views, and cross-sectional views of a portion of the electrode assembly of a secondary battery are shown in the image.

[0024] Figure 4 To explain Figure 3b A perspective view of another example of the coating in the electrode fitting shown in the image.

[0025] Figure 5 To explain Figure 3b A perspective view of another example of the coating in the electrode fitting shown in the image.

[0026] Figure 6 To explain Figure 3b A perspective view of another example of the coating in the electrode fitting shown in the image.

[0027] Figure 7 To explain Figure 1 The image shows a perspective view of the secondary battery in its configuration before being housed in the casing.

[0028] Figure 8 This is a perspective view of a secondary battery according to another embodiment of the present invention before it is housed in a casing.

[0029] Figure 9 and Figure 10 They were displayed respectively Figure 1 Another example of a perspective view of the electrode components in a secondary battery, shown in the image. Detailed Implementation

[0030] Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings.

[0031] Examples of the invention are provided to explain it more fully to those skilled in the art, and various other modifications may be made to the examples below. However, the invention can be embodied in many different forms and should not be construed as limited to the exemplary (or exemplary) embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will convey aspects and features of the invention to those skilled in the art.

[0032] Additionally, for simplicity and clarity, the dimensions or thicknesses of various components have been enlarged in the accompanying drawings. The same reference numerals refer to the same elements throughout. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, it will be understood that when element A is referred to as "connected to" element B, element A may be directly connected to element B, or an intermediary element C may exist between element A and element B, such that element A and element B are indirectly connected to each other.

[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise” and / or “comprising”, when used in this specification, specify the presence of the described features, numbers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and / or groups thereof.

[0034] It will be understood that although the terms first, second, etc., may be used herein to describe various components, elements, regions, layers, and / or portions, these components, elements, regions, layers, and / or portions should not be limited by these terms. These terms are used only to distinguish one component, element, region, layer, and / or portion from another component, element, region, layer, and / or portion. Thus, for example, without departing from the teachings of the invention, the first component, first element, first region, first layer, and / or first portion discussed below may be referred to as a second component, second element, second region, second layer, and / or second portion.

[0035] For ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “up,” etc., may be used herein to describe the relationship between one element or feature illustrated in the figures and another element or feature. It will be understood that, in addition to the orientations depicted in the figures, spatial relative terms are intended to encompass different orientations of the device in use or operation. For example, if an element or feature in the figures is flipped, an element described as “below” or “under” other elements or features would be oriented “above” or “upon” other elements or features. Thus, the exemplary term “below” can encompass both above and below orientations.

[0036] refer to Figure 1 This image shows a perspective view illustrating various embodiments of a secondary battery according to the present invention. (Reference) Figure 2 , showing along Figure 1 The image shows a cross-sectional view of the secondary battery taken from line 2-2. Also, refer to... Figures 3a to 3c , showed Figure 1 The image shows an exploded perspective view, a perspective view, and a cross-sectional view of a portion of the electrode assembly in a secondary battery. References will be made below. Figure 1 , Figure 2 , Figure 3a and Figure 3b The secondary battery 100 of the present invention is described.

[0037] As in Figure 1 , Figure 2 , Figure 3a and Figure 3b As shown, the secondary battery 100 includes an electrode fitting 110, a first terminal portion 120, a second terminal portion 130, a housing 140, and a cap fitting 150. Here, the cap fitting 150 may include a cover plate 151 that seals the upper opening 141 of the housing 140.

[0038] First, the electrode fitting 110 can be formed by winding a stack of a first electrode plate, a separator, and a second electrode plate, which are formed as thin plates or films, into a jelly roll shape. Additionally, a coating 116 can be further formed on the outermost surface of the jelly roll-shaped electrode fitting 110.

[0039] Here, the first electrode plate 111 can operate as a negative electrode, and the second electrode plate 112 can operate as a positive electrode; conversely, the first electrode plate 111 can operate as a positive electrode, and the second electrode plate 112 can operate as a negative electrode. However, in this invention, for ease of explanation, as an example, it will be assumed that the first electrode plate 111 operates as a negative electrode and the second electrode plate 112 operates as a positive electrode.

[0040] A first electrode plate 111 is formed by coating a first electrode active material 111b, such as graphite or carbon, onto a first electrode current collector 111a made of metal foil (such as copper, copper alloy, nickel, or nickel alloy). This may include a first electrode tab 114 (or a first uncoated portion), which is a region where the first electrode active material is not applied. The first electrode tab 114 serves as a current channel between the first electrode plate 111 and the first current collector plate 121. Here, in Figure 3a and Figure 3b As shown, the first electrode connector 114 can extend toward one side of the electrode fitting 110 and extend to a predetermined length.

[0041] The second electrode current collector 112a is formed by coating a second electrode active material 112b (such as a transition metal oxide) onto a second electrode current collector 112a made of a metal foil (such as aluminum or an aluminum alloy), and may include a second electrode tab 115 (or a second uncoated portion), the second electrode tab 115 being the area where the second electrode active material 112b is not applied. The second electrode tab 115 serves as a current channel between the second electrode plate 112 and the second current collector plate 131. Here, as... Figure 3a and Figure 3b As shown, the second electrode connector 115 can extend to the other side of the electrode fitting 110 and extend for a predetermined length. That is, in the electrode fitting 110, the first electrode connector 114 and the second electrode connector 115 can extend to both sides in the longitudinal direction y, respectively.

[0042] A separator 113 can be inserted between the first electrode plate 111 and the second electrode plate 112 to prevent electrical short circuits and ensure the movement of lithium ions. In the winding direction (x), the separator 113 can extend further than the first electrode plate 111 and the second electrode plate 112, such that the separator 113 can be located at the outermost edge of the electrode assembly 110. For example, compared to the first electrode plate 111 and the second electrode plate 112, the separator 113 can be wound at least once more on the outermost surface of the electrode assembly 110. Of course, the separator 113 can expose the first electrode tab 114 and the second electrode tab 115 to the outside. In the longitudinal direction y of the electrode assembly 110, the separator 113 can be formed at the central region A. That is, in the electrode assembly 110, the first electrode tab 114, the separator 113, and the second electrode tab 115 can be sequentially positioned along the longitudinal direction y.

[0043] The separator 113 may be formed of a porous membrane comprising at least one selected from the group consisting of: polystyrene (PS), polyethylene (PE), polypropylene (PP), polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyurethane (PU), polymethylpentene (PMP), polyethylene terephthalate (PET), polycarbonate (PC), polyester, polyvinyl alcohol (PVA), polyacrylonitrile (PAN), silicone acrylate rubber, ethylene-methyl acrylate copolymer, polymethylene oxide (PMO), polymethyl methacrylate (PMMA), polyethylene oxide (PEO), polyamide (PA), polyamide-imide (PAI), polysulfone (PSF), polyethyl sulfone (PES), polyphenylene sulfide (PPS), polyarylate (PAR), polyimide (PI), polyarylamide (PA), cellulose, modified cellulose, melamine resins, and phenolic resins.

[0044] Furthermore, after the electrode fitting 110 is wound, a coating 116 made of heat-resistant material can be further formed on the surface of the outermost partition 113. That is, the coating 116 can be applied to cover the outer surface of the partition 113. Of course, in this case, the first electrode contact 114 and the second electrode contact 115 can be exposed outside the coating 116. That is, in the electrode fitting 110, the first electrode contact 114 and the second electrode contact 115 can extend from the coating 116 to both sides in the longitudinal direction of the electrode fitting 110.

[0045] Here, coating 116 may comprise a single substance or a mixture of two or more substances selected from the group consisting of: polyimide, polybutylene terephthalate (PBT), polyamide-imide (PAI), perfluoroalkoxy (PFA), polysulfone (PSF), polyarylsulfone (PAS), polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), and polyvinyl naphthalene (PEN), which are liquid polymer materials with strong heat resistance. Coating 116 may be formed by spraying, but the invention is not limited thereto.

[0046] The coating 116 is made of a heat-resistant material, thus preventing abnormal heat generation of the electrode fitting 110 from being transferred to the outside through the housing 140. Of course, the coating 116 also prevents external heat from being transferred to the inside of the electrode fitting 110 through the housing 140. Furthermore, since the coating 116 is made of an insulating material, the insulation between the electrode fitting 110 and the housing 140 is improved. Naturally, because the coating 116 is made of an insulating material, a separate insulating strip is not required on the outermost surface of the electrode fitting 110.

[0047] As another example, such as Figure 4 As shown, coating 116 exposes the upper surface 110x of the separator 113 and the lower surface 110y of the electrode fitting 110 to the outside. That is, coating 116 can be formed to cover only the long side of the electrode fitting 110. Of course, coating 116 can be formed to cover the separator 113 on the long side of the electrode fitting 110. Coating 116 can be formed to cover only the central region A on the long side of the electrode fitting 110. Here, when coating 116 is formed to cover only the central region A on the long side of the electrode fitting 110, the electrolyte can be more easily absorbed into the electrode fitting 110.

[0048] In addition, such as Figure 5As shown, the coating 116 may have a plurality of holes 116a to expose the septa 113 on the long side of the electrode fitting 110 to the outside. Here, the holes 116a may be arranged in a dot array or a matrix. Furthermore, although each hole 116a is shown to have a circular shape, its shape can be varied in various ways, including polygonal shapes, etc. Additionally, the coating 116 may also expose the septa 113 on each of the upper surface 110x and lower surface 110y of the electrode fitting 110 to the outside.

[0049] In addition, such as Figure 6 As shown, a plurality of holes 116a may be provided in the coating 116, such that the coating 116 covers the entire central region A of the electrode fitting 110. In this case, the holes 116a may be partially exposed on the outer side of the partition 113 on the long side, upper surface, and lower surface of the electrode fitting 110. Here, when the holes 116a include multiple holes, they may be arranged in a dot array or a matrix. Of course, although each hole 116a is illustrated as circular, the shape may be changed in various ways, including polygonal shapes, etc.

[0050] As described above, by further forming pores 116a in the coating 116, the electrolyte can be more easily absorbed into the electrode fitting 110.

[0051] like Figure 7 As shown in the figure, in the electrode accessory 110, after the outermost partition 113 is fixed by the fixing strap 117, the first electrode connector 114 and the second electrode connector 115 can be electrically connected by welding to the first electrode connection part 121a of the first current collector plate 121 and the second electrode connection part 131a of the second current collector plate 131, which are fixed to the cover accessory 150.

[0052] Electrode fitting 110 is housed together with the electrolyte in housing 140. The electrolyte may include lithium salts, such as LiPF6 or LiBF4 in organic solvents, such as EC, PC, DEC, EMC, or DMC. Alternatively, the electrolyte may be in liquid, solid, or gel form.

[0053] The first terminal portion 120 is made of metal and is electrically connected to the first electrode tab 114 of the first electrode plate 111. The first terminal portion 120 includes a first current collector plate 121, a terminal post 122, and a terminal plate 123. Here, the terminal post 122 is electrically / mechanically connected between the first current collector plate 121 and the terminal plate 123.

[0054] The first current collector plate 121 includes a first electrode connection portion 121a that contacts and is welded to a first electrode tab 114 of a first electrode plate 111, and a first terminal connection portion 121b that bends and extends from the upper end of the first electrode connection portion 121a and is electrically and mechanically connected to a terminal post 122. The first terminal connection portion 121b includes a terminal hole 121c penetrating between its upper and lower surfaces, and the terminal post 122 is inserted therein for riveting or welding. The first current collector plate 121 is made of, for example, copper or a copper alloy. However, the first current collector plate 121 is not limited to these materials.

[0055] Terminal post 122 extends upward through cover plate 151 (described later) for a predetermined length and is electrically connected to a first current collector plate 121 below cover plate 151. Additionally, terminal post 122 extends for a predetermined length to the upper part of cover plate 151 and is inserted into terminal hole 121c of the first current collector plate 121 from the lower part of cover plate 151, and is then riveted or soldered. Here, terminal post 122 is electrically insulated from cover plate 151.

[0056] Terminal plate 123 has a through hole 123a between its upper and lower surfaces, and terminal post 122 is coupled to and welded to the hole 123a. Terminal plate 123 may be coupled to terminal post 122 on the upper part of cover plate 151. For example, a laser beam may be provided to the boundary region between the upwardly exposed terminal post 122 and terminal plate 123, and this boundary region may be melted, then cooled and welded.

[0057] The second terminal portion 130 is also made of metal and is electrically connected to the second electrode tab 115 of the second electrode plate 112. The second terminal portion 130 may include a second current collector plate 131 and a terminal region 132. The second current collector plate 131 includes a second electrode connection portion 131a that contacts and is welded to the second electrode tab 115 of the second electrode plate 112, and a second terminal connection portion 131b that bends and extends from the upper end of the second electrode connection portion 131a and is electrically and mechanically connected to the protrusion 151a of the cover plate 151. The second terminal connection portion 131b has a terminal hole 131c that penetrates between its upper and lower surfaces, and the protrusion 151a is fitted and welded thereto. The second current collector plate 131 may be made of, for example, aluminum or an aluminum alloy. However, the second current collector plate 131 is not limited to these materials.

[0058] Terminal region 133 may extend upward from cover plate 151. When cover plate 151 is formed, terminal region 133 may be formed by forging or by welding a separate metal plate. When terminal region 133 is formed by a separate metal plate, it may be electrically and mechanically connected to the upper surface of cover plate 151.

[0059] Additionally, terminal region 133 may be formed of aluminum or an aluminum alloy, and is the same as cover plate 151. Here, terminal region 132 is electrically connected to cover plate 151. Cover plate 151 and housing 140, which will be described below, have the same polarity (e.g., positive polarity) as second terminal portion 130. Of course, correspondingly, second terminal portion 130 can be used as a positive electrode terminal.

[0060] The housing 140 is made of aluminum, aluminum alloy or conductive metal (such as nickel-plated steel) and has a generally hexahedral shape, in which an upper opening 141 is formed, into which the electrode fitting 110 can be inserted and installed. Figure 2 The diagram shows the state in which the housing 140 and the cap fitting 150 are connected to each other, and the upper opening 141 of the housing 140 corresponds to the outer peripheral portion connected to the cap fitting 150. At the same time, the inner surface of the housing 140 can be insulated to insulate it from the electrode fitting 110, the first terminal portion 120, the second terminal portion 130, and the cap fitting 150.

[0061] The cap fitting 150 is connected to the housing 140. The cap fitting 150 specifically includes a cover plate 151, an upper insulating member 152, a plug 153, a safety vent 154, and a lower insulating member 155.

[0062] The cover plate 151 can seal the upper opening of the housing 140 and can be formed of the same material as the housing 140. For example, the cover plate 151 can be joined to the housing 140 by laser welding. Here, the cover plate 151 can have the same polarity as the second terminal portion 130. Furthermore, the cover plate 151 and the welded housing 140 can have the same polarity.

[0063] An upper insulating member 152 is formed between the terminal plate 123 and the cover plate 151. Furthermore, the upper insulating member 152 is in close contact with both the cover plate 151 and the terminal plate 123. The upper insulating member 152 insulates the cover plate 151 and the terminal plate 123 from each other.

[0064] The plug 153 seals the electrolyte injection hole of the cover plate 151, and the safety vent 154 is installed in the vent hole of the cover plate 151 and forms a notch so that it can be opened under a set pressure.

[0065] The lower insulating member 155 can be inserted between the first current collector plate 121 and the cover plate 151, and between the cover plate 151 and the terminal post 122. The lower insulating member 155 can prevent external moisture from penetrating into the inside of the secondary battery 100 or prevent the electrolyte contained in the secondary battery 100 from leaking to the outside. In addition, the lower insulating member 155 can also be in close contact with the upper insulating member 152.

[0066] In addition, the lower insulating member 155 insulates the first current collector plate 121 and the cover plate 151 from each other, and insulates the terminal post 122 and the cover plate 151 from each other.

[0067] refer to Figure 8 This shows a perspective view illustrating a secondary battery according to another embodiment of the invention before it is housed in a casing. The perspective and cross-sectional views of the secondary battery 200 are comparable to... Figure 1 and Figure 2 The perspective view and cross-sectional view of the secondary battery 100 shown are the same. However, in the secondary battery 200, after the outermost separator 113 is fixed by the fixing strap 117, the first electrode connector 114 and the second electrode connector 115 can be welded to the first electrode connection portion 121a of the first current collector plate 121 and the second electrode connection portion 131a of the second current collector plate 131, which are fixed to the cover fitting 150, respectively, and then a coating 216 can be formed. That is, the coating 216 can be applied to cover not only the electrode fitting 110, but also the first current collector plate 121 and the second current collector plate 131. In this case, the electrode fitting 110 can have a short side surface, on which the first electrode connector 114 and the second electrode connector 115 are located and exposed to the outside. Of course, the coating 216 can also be formed to cover the fixing strap 117.

[0068] The coating 216 can be formed to cover not only the central region A (in which the partition 113 is located on the long side of the electrode fitting 110), but also the first current collector plate 121 and the second current collector plate 131 connected to the first electrode terminal 114 and the second electrode terminal 115. That is, the coating 216 can be formed to cover both long side surfaces of the electrode fitting 110. In addition, the coating 216 can be formed to cover the upper and lower surfaces of the electrode fitting 110.

[0069] To increase the absorption of electrolyte by electrode accessory 110, such as Figure 5 and Figure 6 As shown, coating 216 may have holes formed to expose a portion of the septum 113 of electrode fitting 110 to the outside.

[0070] refer to Figure 9 , showed Figure 1 Another example of a perspective view of the electrode components in a secondary battery, shown in the image.

[0071] The electrode accessory 310 can be formed in a stacked form, wherein the first electrode plate 311, the second electrode plate 312, and the partition plate 313 between the first electrode plate 311 and the second electrode plate 312 are stacked sequentially. That is, the electrode accessory 310 is not wound in the form of a jelly roll, but is formed in the shape of a cuboid, wherein the square first electrode plate 311, the square partition plate 313, and the square second electrode plate 312 are stacked sequentially.

[0072] Here, the first electrode plate 311 can operate as a negative electrode, and the second electrode plate 312 can operate as a positive electrode; conversely, the first electrode plate 311 can operate as a positive electrode, and the second electrode plate 312 can operate as a negative electrode. However, in this invention, for ease of explanation, as an example, it will be explained assuming that the first electrode plate 311 operates as a negative electrode and the second electrode plate 312 operates as a positive electrode.

[0073] A first electrode plate 311 is formed by coating a first electrode active material 311b, such as graphite or carbon, onto a first electrode current collector 311a made of metal foil (such as copper, copper alloy, nickel, or nickel alloy). The first electrode plate 314 (or a first uncoated portion) may be included, whereby the first electrode active material is not applied. The first electrode plate 314 serves as a current channel between the first electrode plate 311 and the first current collector plate 121. Here, the first electrode plate 314 may extend towards one side of the electrode fitting 310 and extend for a predetermined length.

[0074] A second electrode plate 312 is formed by coating a second electrode active material 312b (such as a transition metal oxide) onto a second electrode current collector 312a made of a metal foil (such as aluminum or an aluminum alloy). The plate may include a second electrode tab 315 (or a second uncoated portion), which is a region where the second electrode active material 312b is not applied. The second electrode tab 315 serves as a current channel between the second electrode plate 312 and the second current collector tab 331. Here, the second electrode tab 315 may extend to the other side of the electrode fitting 310 and extend for a predetermined length. That is, in the electrode fitting 310, the first electrode tab 314 and the second electrode tab 315 may extend to both sides in the longitudinal direction y, respectively.

[0075] A separator 313 can be inserted between the first electrode plate 311 and the second electrode plate 312 to prevent electrical short circuits and ensure the movement of lithium ions. The electrode fitting 310 may have a separator 313 located at the outermost part. That is, the separator 313 may be located on the long side 310z of the electrode fitting 310.

[0076] The partition 313 can be formed in the central region A along the longitudinal direction y of the electrode fitting 310. That is, in the electrode fitting 310, when viewed from the long side, the first electrode contact 314, the partition 313, and the second electrode contact 315 can be sequentially positioned along the longitudinal direction y. The material of the partition 313 can be the same as that used in... Figures 3a to 3c The electrode accessory 110 shown in the image is made of the same material.

[0077] Of course, in electrode fitting 310, coating 116 can be further formed on the outermost partition 313. Here, the shape of coating 116 can be... Figure 3b , Figure 4 , Figure 5 and Figure 6 Any of the coatings 116 shown in the image.

[0078] In addition, such as Figure 10 As shown, coating 116 can be applied to the inner surface of the outermost partition 313. Of course, after connecting the electrode fitting 310, coating 116 can be applied to the inner surface of the outermost partition 313, and then the electrode fitting 310 can be connected to coating 116. Here, the outermost partition 313 can be the outermost partition located on the electrode fitting 310. Furthermore, the inner surface of the outermost partition 313 can be the surface facing the first electrode plate 311 or the second electrode plate 312, rather than the outer surface exposed to the outside of the outermost partition 313.

[0079] Of course, with Figure 5 The same holes formed in the coating 116 shown in the figure can be formed in the coating 116 applied to the inner surface of the outermost partition 313.

[0080] While the foregoing embodiments for implementing the secondary battery according to the invention have been provided, it should be understood that the embodiments described herein should be considered descriptive rather than restrictive, and various changes in form and detail may be made therein without departing from the spirit and scope of this disclosure as defined by the following claims.

[0081] Industrial applicability

[0082] This invention can be applied to the field of secondary batteries and battery packs composed of secondary batteries.

Claims

1. A secondary battery, comprising: An electrode assembly includes a first electrode plate, a second electrode plate, and a partition plate inserted between the first electrode plate and the second electrode plate, wherein a first electrode tab, which is the uncoated portion of the first electrode plate, extends in one direction. The housing that receives the electrode fitting; A cover plate for sealing the upper end of the housing; and A first terminal portion electrically connected to the first electrode plate of the electrode accessory, the first terminal portion being exposed on the outside of the cover plate. The separator is located at the outermost edge of the electrode assembly, and a coating is formed by applying a heat-resistant material to the surface of the outermost separator. The coating includes a plurality of pores, and the coating is formed such that the plurality of pores are arranged in a dot array or matrix, and the partition is exposed to the outside through the plurality of pores. The coating is a single substance or a mixture of two or more substances selected from the group consisting of: polyimide, polybutylene terephthalate (PBT), polyamide-imide (PAI), perfluoroalkoxy (PFA), polysulfone (PSF), polyarylsulfone (PAS), polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), and polyvinyl naphthalene (PEN), which are liquid polymer materials with strong heat resistance.

2. The secondary battery according to claim 1, wherein the electrode fitting is formed by winding a stack of the first electrode plate, the separator, and the second electrode plate into the shape of a jelly roll, and the second electrode tab, which is the uncoated portion of the second electrode plate, extends in a direction opposite to the first electrode tab.

3. The secondary battery according to claim 1, wherein the electrode assembly is formed in the form of a stack, wherein the first electrode plate, the separator, the second electrode plate and the separator are stacked in sequence, and the second electrode terminal piece, which is the uncoated portion of the second electrode plate, extends in a direction opposite to the first electrode terminal piece.

4. The secondary battery according to claim 2 or 3, wherein the coating is applied to cover all outer surfaces of the separator, and the first electrode tab and the second electrode tab extend from the coating toward both sides in the longitudinal direction of the electrode fitting.

5. The secondary battery of claim 2, wherein the coating is applied to cover a separator located on the long side of the electrode assembly, and the separator is exposed to the outside through the upper and lower surfaces of the electrode assembly.

6. The secondary battery according to claim 3, wherein the coating is applied to the inner surface of the outermost separator.

7. The secondary battery according to claim 2, wherein the first electrode terminal is connected at the first terminal portion to a first current collector plate housed inside the housing, and the second electrode terminal is connected at the second terminal portion exposed outside the cover plate to a second current collector plate housed inside the housing.

8. The secondary battery according to claim 7, wherein the coating is applied to cover the fixing strap and the first current collector plate and the second current collector plate, and the fixing strap is used to fix the outermost separator to the outermost surface of the electrode assembly.

9. The secondary battery according to claim 1, wherein the separator is a porous membrane comprising at least one selected from the group consisting of: polystyrene (PS), polyethylene (PE), polypropylene (PP), polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyurethane (PU), polymethylpentene (PMP), polyethylene terephthalate (PET), polycarbonate (PC), polyester, polyvinyl alcohol (PVA), polyacrylonitrile (PAN), silicone acrylate rubber, ethylene-methyl acrylate copolymer, polymethylene oxide (PMO), polymethyl methacrylate (PMMA), polyethylene oxide (PEO), polyamide (PA), polyamide-imide (PAI), polysulfone (PSF), polyethyl sulfone (PES), polyphenylene sulfide (PPS), polyaramid (PAR), polyimide (PI), aromatic polyamide (PA), cellulose, modified cellulose, melamine resins, and phenolic resins.

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