Battery and method for manufacturing battery

Abstract

The present invention is a battery having an electrode body (charge / discharge body 10) in which a positive electrode sheet 11 and a negative electrode sheet 12 are laminated, the positive electrode sheet having: a positive electrode current collector layer 11S having a positive electrode current collector foil main body 11a and a positive electrode current collector tab 11b protruding from an edge 11c in the width direction of the positive electrode current collector foil main body; a positive electrode active material layer (11T) laminated on the positive electrode current collector foil main body except an edge region (720) in the width direction of the positive electrode current collector foil main body; and a heat-resistant layer 11Q laminated on the edge region, the base region 710 of the positive electrode collector tab, and the positive electrode active material layer.

Description

Technical Field

[0001] The present invention relates to a battery and a method for manufacturing the battery. Background Art

[0002] In the past, a secondary battery having a plurality of terminal portions (electrode current collecting tabs) formed on a wound electrode sheet is known. Patent document 1 discloses a positive electrode sheet formed by protruding a positive electrode current collecting tab from an end portion in the width direction of a metal foil. In the positive electrode sheet, there is an area where a positive electrode active material is not formed in the edge area in the width direction of the metal foil, and an insulating layer is formed in this area and at the base of the positive electrode current collecting tab close to the metal foil. The insulating layer can strengthen the base of the positive electrode current collecting tab where stress is easily concentrated.

[0003] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application No. 2021-500734 Summary of the invention Problem that the invention aims to solve For the positive electrode sheet of the secondary battery already described, due to the difference in elongation between the active material layer and the insulating layer, when the metal foil is rolled after being coated with the active material, and when the positive electrode sheet, the negative electrode sheet and the separator are wound to form an electrode body, there is room to reduce deformation such as wrinkles or warping near the root of the electrode collector ear.

[0004] Therefore, an object of the present invention is to provide a battery in which the electrode current collecting tab of the positive electrode sheet does not deform and a method for manufacturing the battery.

[0005] Means used to solve problems In order to achieve the above-mentioned purpose, the present invention is a battery having a charging and discharging body formed by stacking a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet has: a positive electrode collector layer having a positive electrode collector foil body and a positive electrode collector ear protruding from the edge end of the positive electrode collector foil body in the width direction; a positive electrode active material layer stacked on the positive electrode collector foil body except for the edge region of the positive electrode collector foil body in the width direction; and a heat-resistant layer stacked on the edge region, the base region of the positive electrode collector ear and the positive electrode active material layer.

[0006] Furthermore, the present invention is a method for producing a battery having an electrode body, wherein the electrode body is produced by winding and stacking the above-described positive electrode sheet and negative electrode sheet with a separator interposed therebetween.

[0007] Effects of the Invention According to the present invention, a battery in which the electrode current collecting tab of a positive electrode sheet is not deformed and a method for manufacturing the battery can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a perspective view showing the battery 1 .

[0009] Figure 2 It is a cross-sectional perspective view showing the periphery of the negative electrode terminal 42 of the battery 1 .

[0010] Figure 3 It is a cross-sectional view showing the periphery of the negative electrode terminal 42 of the battery 1 .

[0011] Figure 4 It is a cross-sectional perspective view showing the periphery of the positive electrode terminal 41 of the battery 1 .

[0012] Figure 5 It is a cross-sectional view showing the periphery of the positive electrode terminal 41 of the battery 1 .

[0013] Figure 6 It is an exploded perspective view showing the battery 1 .

[0014] Figure 7 It is a perspective view showing the charging and discharging body 10 of the battery 1 .

[0015] Fig. 8A It is a top view of the positive electrode sheet 11 .

[0016] Figure 8B This is a cross-sectional view of the positive electrode sheet 11 as viewed in the short-side direction (width direction: Z-axis direction) from the 8B direction.

[0017] Figure 8C This is a cross section of the positive electrode sheet 11 according to the second embodiment.

[0018] Fig. 9A The negative electrode sheet 12 is wound and separated from the separator 13. Fig. 8A The cross-sectional view of an example of the structure in which the positive electrode sheets 11 are stacked is shown.

[0019] Fig. 9B The negative electrode sheet 12 is wound and separated from the separator 13. Figure 8B The cross-sectional view of an example of the structure in which the positive electrode sheets 11 are stacked is shown.

[0020] Fig.10 It is a perspective view showing electrodes (positive electrode sheet 11 and negative electrode sheet 12 ) and separator 13 of the battery 1 .

[0021] Fig.11 It is an exploded perspective view showing the periphery of the negative electrode terminal 42 of the battery 1 .

[0022] Fig.12 It is an exploded perspective view showing the cover 52 and the sealing plug 53 of the battery 1 .

[0023] Fig.13 It is an exploded perspective view showing the periphery of the positive electrode terminal 41 of the battery 1 .

[0024] Fig.14 It is a perspective view showing a method for manufacturing the collector foils (positive electrode collector layer 11S and negative electrode collector layer 12S) of the electrodes (positive electrode sheet 11 and negative electrode sheet 12 ) of the battery 1 . DETAILED DESCRIPTION

[0025] The structure of the battery 1 according to the first embodiment will be described with reference to the drawings. The battery 1 is, for example, Figures 1 to 5 As shown, the battery 1 includes: a charge-discharge body (electrode body) 10 for performing charge and discharge; a current collector 20 connected to the charge-discharge body 10; a current interrupter 30 connected to the current collector 20; an external terminal 40 connected to the current collector 20 or the current interrupter 30; and an outer body 50 for accommodating or mounting the structural members of the battery 1. In addition, the battery 1 includes: an insulator 60 for insulating the structural members of the battery 1 from the outer body 50; and a sealing body 70 for sealing the structural members of the battery 1 and the outer body 50.

[0026] The charge / discharge body 10 can be charged and discharged. Figures 2 to 7 The charge-discharge body 10 shown includes a positive electrode 11, a negative electrode 12, a separator 13 (insulating member), and an electrolyte 14. The charge-discharge body 10 is as shown in FIG. Figure 7 As shown, the structure is formed by winding structural members stacked in this order: a positive electrode 11 , a separator 13 , a negative electrode 12 , and a separator 13 into a rectangular parallelepiped shape.

[0027] The positive electrode sheet 11 is, for example, Figure 7 As shown, it includes a positive electrode collector layer 11S (collector foil) composed of a sheet of metal foil and a positive electrode active material layer 11T stacked and bonded to the positive electrode collector layer 11S. The positive electrode collector layer 11S includes a positive electrode collector foil body 11a and a positive electrode collector tab 11b. The positive electrode collector foil body 11a is wound. The positive electrode active material layer 11T is stacked and bonded to the positive electrode collector foil body 11a.

[0028] The positive electrode current collecting tab 11 b (terminal portion) is, for example, Figure 7 As shown in the figure, along the long side direction (winding direction) of the positive electrode current collector foil body 11a, the edge 11c in the width direction (short side direction of the positive electrode current collector foil body 11a) protrudes in the width direction. The positive electrode current collector tab 11b is formed integrally with the positive electrode current collector foil body 11a. A plurality of positive electrode current collector tabs 11b are formed on one positive electrode current collector foil body 11a.

[0029] The structure of the interval between the positive electrode current collecting tabs 11b adjacent to each other in the winding direction includes a structure that is configured to be spaced from one end 11p ( Fig.10) The closer to the other end 11q, the longer the interval between adjacent positive electrode collector tabs 11b is. That is, all positive electrode collector tabs 11b are not limited to a structure in which the interval between adjacent positive electrode collector tabs 11b along the winding direction is relatively longer as the one end 11p of the positive electrode collector foil body 11a approaches the other end 11q. For example, the adjacent positive electrode collector tabs 11b along the winding direction may also be configured such that equal intervals and unequal intervals are repeated alternately from the one end 11p of the positive electrode collector foil body 11a toward the other end 11q.

[0030] The metal foil of the positive electrode current collector layer 11S is formed of, for example, aluminum or an aluminum alloy. The positive electrode active material layer 11T contains a positive electrode active material composed of a lithium-containing composite oxide, a binder, a conductive additive, etc. The lithium-containing composite oxide uses, for example, metal elements such as nickel (Ni), cobalt (Co), and manganese (Mn) and lithium (Li).

[0031] The negative electrode sheet 12 is, for example, Figure 7 As shown, it includes a negative electrode collector layer 12S (collector foil) composed of a sheet of metal foil and a negative electrode active material layer 12T stacked and bonded with the negative electrode collector layer 12S. The negative electrode collector layer 12S includes a negative electrode collector foil body 12a and a negative electrode collector tab 12b. The negative electrode active material layer 12T is stacked and bonded with the negative electrode collector foil body 12a. The negative electrode active material layer 12T is, for example, opposite to the entire area of ​​the negative electrode collector foil body 12a along the short side direction (Z-axis direction).

[0032] The negative electrode current collecting tab 12 b (terminal portion) is, for example, Figure 7 As shown, the negative electrode collector tab 12b protrudes from the edge 12c along the long side direction (winding direction) of the negative electrode collector foil body 12a to the short side direction of the negative electrode collector foil body 12a. The negative electrode collector tab 12b protrudes in the same direction as the positive electrode collector tab 11b of the positive electrode sheet 11 when stacked with the positive electrode sheet 11 via the separator 13. The negative electrode collector tab 12b is separated from the positive electrode collector tab 11b of the positive electrode sheet 11 when stacked with the positive electrode sheet 11 via the separator 13. The negative electrode collector tab 12b is formed integrally with the negative electrode collector foil body 12a. A plurality of negative electrode collector tabs 12b are formed on one negative electrode collector foil body 12a.

[0033] The negative electrode current collecting tabs 12b are formed with so-called unequal spacing similarly to the positive electrode current collecting tabs 11b. That is, the spacing between the negative electrode current collecting tabs 12b adjacent to each other in the winding direction is formed so as to be equal to the spacing between the negative electrode current collecting tabs 12b and the positive electrode current collecting tabs 11b. Fig.10), the intervals between the negative electrode collector tabs 12b adjacent to the other end 12q near the winding end of the negative electrode collector foil body 12a are relatively long. All the negative electrode collector tabs 12b overlap when the negative electrode collector foil body 12a is wound. Among them, the intervals between the negative electrode collector tabs 12b are similar to the intervals between the positive electrode collector tabs 11b, and the structure includes the negative electrode collector tabs 12b that are configured such that the intervals between the adjacent negative electrode collector tabs 12b are relatively longer as the one end 12p of the negative electrode collector foil body 12a approaches the other end 12q.

[0034] The metal foil of the negative electrode current collecting layer 12S is formed of, for example, copper or a copper alloy. The negative electrode active material layer 12T contains a negative electrode active material made of a carbon-based material, a binder, a conductive additive, etc. As the carbon-based material, for example, graphite is used.

[0035] The diaphragm 13 (insulator) is, for example, Figure 7 As shown, the positive electrode sheet 11 and the negative electrode sheet 12 can be insulated and lithium ions can pass through. The separator 13 is formed in a sheet shape. The separator 13 is longer in width along the short side direction (Z-axis direction) than the positive electrode collector foil body 11a of the positive electrode sheet 11 and the negative electrode collector foil body 12a of the negative electrode sheet 12. The two ends of the positive electrode collector foil body 11a of the positive electrode sheet 11 along the short side direction are located within the range of the separator 13 along the short side direction, and the two ends of the negative electrode collector foil body 12a of the negative electrode sheet 12 along the short side direction are located within the range of the separator 13 along the short side direction. The separator 13 is made of a porous material. The separator 13 uses polyethylene (PE: PolyEthylene) or polypropylene (PP: PolyPropylene). A heat-resistant insulating component can also be used instead of the separator 13. The heat-resistant insulating component uses ceramics, for example. Such a structure is a so-called separator-free structure.

[0036] The electrolyte 14 corresponds to a so-called electrolytic solution. The electrolyte 14 is impregnated in the separator 13. The electrolyte 14 contains an organic solvent, a supporting salt, and an additive. For example, a carbonate ester is used as the organic solvent. For example, a lithium salt is used as the supporting salt. The electrolyte 14 and the separator 13 may also be replaced with a sheet-like solid electrolyte.

[0037] Fig. 8A is a top view of the positive electrode sheet 11, Figure 8B 8B is a cross-sectional view of the positive electrode sheet 11 in the short side direction (width direction: Z-axis direction). Fig. 8A in, omit Figure 8B11A is a diagram of a heat-resistant layer 11Q. The positive electrode active material layer 11T is stacked on the positive electrode current collector foil body 11a in the entire area of ​​both surfaces of the positive electrode current collector foil body 11a except for the edge region 720, which is a region with a predetermined width from the edge 11c on the positive electrode current collector tab 11b side. The edge region 720 is a region (e.g., 2-6 mm) between the edge 11Ta in the short side direction of the positive electrode active material layer 11T and the edge 11c in the short side direction of the positive electrode current collector foil body 11a. The arrows marked with the reference numerals indicate the Z-axis direction.

[0038] The positive electrode current collector tab 11b has a joint portion 760 welded to the current collector 20 connected to the external terminal 40 and a rounded portion 740 connected to the edge 11c of the positive electrode current collector foil body 11a from the joint portion 760. Reference numeral 710 is a base region of the positive electrode current collector tab 11b. The base region 710 is a region between the edge 11c of the positive electrode current collector foil body 11a, which is the starting end of the rounded portion 740, and the terminal end of the front end side of the positive electrode current collector tab 11b.

[0039] As an example, the width of the edge region 720 is less than the width of the base region 710. Thus, the positive electrode active material layer 11T can be used to the maximum extent. This is preferred from the perspective of improving the input and output of the battery. As another example, the width of the edge region 720 is greater than the width of the base region 710. Thus, the width of the active material layer 11T to the edge end 11c is expanded, so that the layer can be stably formed in this region.

[0040] The heat-resistant layer 11Q is laminated on the entire region of the positive electrode active material layer 11T and the region 700 formed by the edge region 720 and the base region 710. After the positive electrode active material layer 11T and the heat-resistant layer 11Q are formed on the positive electrode current collector foil body 11a, a pressing process is performed by a pressing roller, and a positive electrode current collector tab 11b is formed by punching, cutting or laser processing, thereby obtaining Figure 8B The positive electrode sheet 11.

[0041] If the positive electrode sheet, the negative electrode sheet, and the separator are wound, the heat-resistant layer is located between the separator and the positive electrode active material layer. In order not to reduce the battery reaction, the heat-resistant layer needs to have a structure that allows lithium ions in the electrolyte to pass through easily. Therefore, the heat-resistant layer can be made of any porous material with a porous structure. For example, a ceramic coating. Regarding the thickness of the heat-resistant layer, if the battery performance (reaction) is emphasized, it is more advantageous to have a thin heat-resistant layer. On the contrary, if safety is emphasized, the heat-resistant layer is made thicker.

[0042] according to Figure 8BIn the positive electrode sheet 11, the active material layer 11T, the edge region 720 of the positive electrode collector foil body 11a, and the base region 710 of the positive electrode collector tab 11b are uniformly covered by the heat-resistant layer 11Q, thereby eliminating the problem of different elongation. As a result, the deformation of the positive electrode collector tab 11b such as bending, warping, and wrinkling when the positive electrode sheet 11 is wound to form the charge-discharge body 10 is suppressed, the bonding between the positive electrode collector tab 11b and the collector 20 is improved, and poor conduction is eliminated.

[0043] The front end of the base region 710 may also be set to be within two times of the distance (760) from the edge 11c of the positive electrode collector foil body 11a to the terminal end of the rounded portion 740 in the protruding direction of the positive electrode collector tab 11b. In this way, the area of ​​the positive electrode collector tab 11b exposed from the heat-resistant layer 11Q can be sufficiently ensured to avoid poor welding between the positive electrode collector tab 11b and the collector 20.

[0044] Figure 8C This is a second embodiment of the positive electrode sheet 11. Figure 8B In the embodiment, a heat-resistant layer 11Q is stacked in the region 700, and in contrast, Figure 8C In the embodiment, an insulating layer 11R is stacked in the region 700 instead of the heat-resistant layer 11Q. The heat-resistant layer 11Q is stacked between the positive electrode active material layer 11T and the insulating layer 11R. The insulating layer 11R increases the rigidity of the positive electrode current collecting tab 11b.

[0045] The insulating layer 11R includes at least an insulating material and an adhesive material. The insulating material includes, for example, at least one selected from aluminum oxide (e.g., α-aluminum oxide), silicon dioxide, acrylic resin, magnesium oxide, calcium oxide, titanium dioxide, zirconium oxide, boehmite, and magnesium hydroxide. The adhesive material includes at least one selected from styrene-butadiene rubber, carboxymethyl cellulose, and salts thereof.

[0046] Fig. 9A The negative electrode sheet 12 is wound and separated from the separator 13. Fig. 8A The cross-sectional view of an example of the structure in which the positive electrode sheets 11 are stacked is shown. Fig. 9B The negative electrode sheet 12 is wound and separated from the separator 13. Figure 8B The cross-sectional view of an example of the structure of stacking the positive electrode sheets 11 shown. The negative electrode active material layer 12T is stacked over the entire area of ​​both sides of the negative electrode current collector foil body 12a. That is, the edge 12c of the negative electrode current collector foil body 12a and the edge 12Ta of the negative electrode active material layer 12T terminate at the same position.

[0047] Moreover, the width of the edge 12c of the negative electrode collector foil body 12a along the short side direction (Z-axis direction) is shorter than the width of the edge 11c of the positive electrode collector foil body 11a of the positive electrode sheet 11 along the short side direction (Z-axis direction). The edge 12c of the negative electrode collector foil body 12a is located within the range of the edge region 720 between the edge 11c of the positive electrode collector foil body 11a of the positive electrode sheet 11 and the edge 11Ta of the positive electrode active material layer 11T. As a result, the position of the edge of the electrode where metal burrs are likely to appear (the edge 12c of the electrode collector foil body 12a) is located on the inner side of the sheet in the width direction than the edge 11c of the positive electrode collector foil body 11a, and short circuit can be suppressed. In addition, the edge 13a of the separator 13 in the width direction is located outside the edge 11c of the positive electrode collector foil body 11a in the width direction. This prevents short circuits.

[0048] Although the example in which the negative electrode current collecting tab 12b protrudes in the same direction as the positive electrode current collecting tab 11b has been described, the current collecting tab 12b may also protrude in the opposite direction to the positive electrode current collecting tab 11b. Fig. 9A , 9B In the figure, 12c and 12Ta indicate the end surface on the opposite side from the protruding side of the negative electrode current collecting tab 12b.

[0049] The current collector 20 is connected to the charging and discharging body 10 . Figures 2 to 5 , Fig.11 as well as Fig.13 The illustrated current collector 20 includes a positive electrode current collector plate 21 and a negative electrode current collector plate 22 .

[0050] The positive electrode collector plate 21 is, for example, Figure 4 and Figure 5 As shown in FIG. 1 , the positive electrode current collecting tab 11 b of the charge / discharge body 10 is electrically connected to the positive electrode terminal 41 via the current interrupter 30. The positive electrode current collecting plate 21 is, for example, Fig.13 As shown in FIG. 1 , the positive electrode collector plate 21 includes a first base portion 21a in the shape of a rectangular parallelepiped, a second base portion 21b in the shape of a rectangular parallelepiped, and a connecting portion 21c that connects the first base portion 21a and the second base portion 21b in a stepped manner at different heights. A recessed portion 21d is formed on the upper surface of the second base portion 21b (the surface on the positive direction side of the Z axis) to make the thickness of the second base portion 21b thinner. A fragile portion 21e that is a ring-shaped recessed fragile portion is formed in the center of the recessed portion 21d. The positive electrode collector plate 21 is formed of, for example, aluminum or an aluminum alloy.

[0051] The negative electrode current collector plate 22 is, for example, Figure 2 and Figure 3 As shown in FIG. 1 , the negative electrode current collecting tab 12 b of the charge / discharge body 10 is electrically connected to the negative electrode terminal 42. The negative electrode current collecting plate 22 is, for example, Fig.11As shown, it includes a rectangular plate-shaped base 22a and an insertion hole 22b penetrating the base 22a. The insertion portion 42b of the negative terminal 42 is inserted into the insertion hole 22b of the negative current collector plate 22. The negative current collector plate 22 is formed of, for example, copper or a copper alloy.

[0052] The current interrupter 30 is connected to the current collector 20 , so that electrical conduction is established between the current collector 20 and the positive electrode terminal 41 . Figure 4 , Figure 5 as well as Fig.13 The current-interrupting body 30 shown includes a diaphragm 31 , a conductive component 32 , and a pair of support platforms 33 .

[0053] The diaphragm 31 is, for example, Fig.13 As shown in the figure, it includes a curved cylindrical main body 31a, a disc-shaped first bonding portion 31b provided at the front end side (Z-axis negative direction side) of the main body 31a, and an annular second bonding portion 31c provided at the base end side (Z-axis positive direction side) of the main body 31a. The first bonding portion 31b is bonded to the recessed portion 21d of the positive electrode collector plate 21. The second bonding portion 31c is bonded to the conductive member 32. The diaphragm 31 is formed of, for example, aluminum or an aluminum alloy.

[0054] The conductive component 32 is, for example, Fig.13 As shown in FIG. 1 , the conductive member 32 is formed into a cylindrical shape. The upper surface (surface on the positive direction side of the Z axis) of the conductive member 32 is bonded to the positive electrode side first insulating plate 62. The peripheral edge of the lower surface (surface on the negative direction side of the Z axis) of the conductive member 32 is bonded to the second bonding portion 31c of the diaphragm 31. The conductive member 32 is formed of, for example, aluminum or an aluminum alloy.

[0055] The support platform 33 is, for example, Fig.13 As shown in FIG. 1 , the support platform 33 includes a main body 33a of a rectangular parallelepiped extending in the short side direction (Y-axis direction) of the battery 1 and foot portions 33b extending downward (Z-axis negative direction) from both sides of the main body 33a in the long side direction (Y-axis direction). One support platform 33 is provided at each end of the diaphragm 31 along the long side direction (X-axis direction) of the battery 1. The main body 33a is mounted on the positive electrode side first insulating plate 62. The foot portion 33b is mounted on the second base portion 21b of the positive electrode collector plate 21. The support platform 33 is formed of, for example, insulating resin.

[0056] The external terminal 40 is connected to the current collector 20 or the current interrupter 30 . Figures 1 to 6 , Fig.11 and Fig.13 The illustrated external terminal 40 includes a positive terminal 41 and a negative terminal 42 .

[0057] The positive terminal 41 is, for example, Figure 5 As shown in FIG. 1 , the positive electrode terminal 41 is connected to the conducting member 32 of the current interrupter 30. Fig.13 As shown, it includes a rectangular plate-shaped base 41a, a cylindrical insertion portion 41b protruding downward (in the negative direction of the Z axis) from the base 41a, and a cylindrical engagement portion 41c protruding downward (in the negative direction of the Z axis) from the periphery of the base 41a.

[0058] The base 41a is, for example, Fig.13 As shown, it is connected to the base 64a of the positive-side second insulating plate 64. The insertion portion 41b is inserted into the insertion hole 64b of the positive-side second insulating plate 64, the positive-side insertion hole 52a of the cover 52, the insertion hole 62b of the positive-side first insulating plate 62, and the insertion hole 32b of the conductive member 32.

[0059] The joining portion 41c is, for example, Fig.13 As shown in FIG. 1 , the positive electrode terminal 41 protrudes downward (in the negative direction of the Z axis) from the insertion hole 32b of the conductive member 32 and is pressed and expanded radially outward to be joined to the conductive member 32. That is, the joining portion 41c is rivet-processed on the periphery of the insertion hole 32b of the conductive member 32. Furthermore, the joining portion 41c is welded to the periphery of the insertion hole 32b of the conductive member 32. The positive electrode terminal 41 is formed of, for example, aluminum or an aluminum alloy.

[0060] The negative electrode terminal 42 is, for example, Figure 3 As shown in FIG. 1 , the negative electrode terminal 42 is connected to the negative electrode collector plate 22. The negative electrode terminal 42 is, for example, Fig.11 As shown, it includes a rectangular plate-shaped base 42a, a cylindrical insertion portion 42b protruding downward (in the negative direction of the Z axis) from the base 42a, and a cylindrical engagement portion 42c protruding downward (in the negative direction of the Z axis) from the periphery of the base 42a.

[0061] The base 42a is, for example, Fig.11 As shown, it is connected to the base 65a of the negative electrode side second insulating plate 65. The insertion portion 42b is inserted into the insertion hole 65b of the negative electrode side second insulating plate 65, the negative electrode side insertion hole 52b of the cover 52, the insertion hole 63b of the negative electrode side first insulating plate 63, and the insertion hole 22b of the negative electrode collector plate 22.

[0062] The engagement portion 42c is, for example, Fig.11 As shown in FIG. 1 , the negative electrode terminal 42 protrudes downward from the insertion hole 22b of the negative electrode collector plate 22 and is pressed and expanded radially outward to be joined to the negative electrode collector plate 22. That is, the joining portion 42c is riveted to the periphery of the insertion hole 22b of the negative electrode collector plate 22. Furthermore, the joining portion 42c is welded to the periphery of the insertion hole 22b of the negative electrode collector plate 22. The negative electrode terminal 42 is formed of, for example, copper or a copper alloy.

[0063] The exterior body 50 accommodates or mounts the structural members of the battery 1 . Figures 1 to 6 and Figures 11 to 13 The outer casing 50 shown includes a container 51 , a cover 52 , and a sealing plug 53 .

[0064] The container 51 is, for example, Figure 2 and Figure 6 As shown in FIG. 1 , the container 51 contains the charge / discharge body 10 and the like covered by the insulating cover 61. The container 51 is composed of a rectangular parallelepiped metal can. The container 51 is, for example, Figure 6 As shown, the container 51 includes an opening 51a opened along the longitudinal direction and a storage portion 51b connected to the opening 51a. The container 51 is formed of, for example, aluminum or an aluminum alloy.

[0065] The cover 52 is, for example, Figure 2 and Figure 6 As shown, the opening 51a of the container 51 is sealed. The cover 52 is opposite to one side portion 10a (side portion) in the charge-discharge body 10, and the positive electrode sheet 11, the diaphragm 13 and the negative electrode sheet 12 are adjacent to one side portion 10a (side portion). The cover 52 is formed by a metal plate in the shape of a long plate. A positive electrode side insertion hole 52a consisting of a circular through hole is formed at one end side of the long side direction of the cover 52. The insertion portion 41b of the positive terminal 41 is inserted into the positive electrode side insertion hole 52a. A negative electrode side insertion hole 52b consisting of a circular through hole is formed at the other end side of the long side direction of the cover 52. The insertion portion 42b of the negative terminal 42 is inserted into the negative electrode side insertion hole 52b.

[0066] The cover 52 is formed with a liquid injection hole 52c consisting of a circular through hole between the positive electrode side insertion hole 52a and the negative electrode side insertion hole 52b. The electrolyte 14 can be injected from the cover 52 into the container 51 through the liquid injection hole 52c. The insertion portion 53b of the sealing plug 53 is inserted into the liquid injection hole 52c. The cover 52 is formed with a cleavage valve 52d in the center of the long side direction. The cover 52 is welded to the container 51. The cover 52 is formed of, for example, aluminum or an aluminum alloy.

[0067] The sealing plug 53 is, for example, Fig.12 As shown in FIG. 5 , the liquid injection hole 52c of the cover 52 is sealed. The sealing plug 53 is formed in a cylindrical shape. The sealing plug 53 includes a head 53a with a relatively large outer diameter and an insertion portion 53b connected to the head 53a and with a relatively small outer diameter. The head 53a of the sealing plug 53 is welded to the cover 52. The sealing plug 53 is formed of, for example, aluminum or an aluminum alloy.

[0068] The insulator 60 insulates the structural members of the battery 1 from the exterior body 50 . Figures 2 to 6 , Fig.11 as well as Fig.13 The illustrated insulator 60 includes an insulating cover 61 , a positive electrode side first insulating plate 62 , a negative electrode side first insulating plate 63 , a positive electrode side second insulating plate 64 , and a negative electrode side second insulating plate 65 .

[0069] The insulating cover 61 is, for example, Figure 6 As shown, the charging and discharging body 10 is covered and insulated. The insulating cover 61 includes: a pair of opposite side surfaces (a first side surface 61a and a second side surface 61b); and an opening 61c between the first side surface 61a (one side surface) and the second side surface 61b (the other side surface) that exposes one side portion 10a of the charging and discharging body 10. The insulating cover 61 covers the portion other than one side of one side portion 10a of the charging and discharging body 10. That is, the insulating cover 61 covers: the other side portion 10b of the charging and discharging body 10 opposite to the one side portion 10a; and the outer peripheral portion 10c of the charging and discharging body 10 located between the one side portion 10a and the other side portion 10b. The insulating cover 61 is formed into a pentahedral shape by folding a polyhedral-shaped sheet into a box shape. The insulating cover 61 is formed, for example, of polypropylene.

[0070] The positive electrode side first insulating plate 62 is, for example, Figure 5 As shown in FIG. 1 , the positive electrode current collector plate 21 and the conductive member 32 are insulated from the cover 52. The positive electrode side first insulating plate 62 is, for example, Fig.13 As shown in FIG. 5 , the first insulating plate 62 on the positive side includes a rectangular plate-shaped base 62a, an insertion hole 62b penetrating the base 62a, and a convex portion 62c that surrounds the edge of the base 62a in an annular shape and protrudes in a direction away from the cover 52. The positive electrode collector plate 21 and the conductive component 32 are accommodated in the space formed by the base 62a and the convex portion 62c of the positive electrode side first insulating plate 62. The insertion portion 41b of the positive electrode terminal 41 is inserted into the insertion hole 62b. The first insulating plate 62 on the positive electrode side is formed of, for example, an insulating resin.

[0071] The negative electrode side first insulating plate 63 is, for example, Figure 3 As shown in FIG. 2 , the negative electrode current collector plate 22 is insulated from the cover 52. The negative electrode side first insulating plate 63 is, for example, Fig.11 As shown in FIG. 5 , the first insulating plate 63 on the negative electrode side includes a rectangular plate-shaped base 63a, an insertion hole 63b penetrating the base 63a, and a convex portion 63c that surrounds the edge of the base 63a in an annular shape and protrudes in a direction away from the cover 52. The negative electrode collector plate 22 is accommodated in a space formed by the base 63a and the convex portion 63c of the negative electrode side first insulating plate 63. The insertion portion 42b of the negative electrode terminal 42 is inserted into the insertion hole 63b. The negative electrode side first insulating plate 63 is formed of, for example, an insulating resin.

[0072] The positive electrode side second insulating plate 64 is, for example, Figure 5 As shown in FIG. 4 , the positive electrode terminal 41 is insulated from the cover 52. The positive electrode side second insulating plate 64 is, for example, Fig.13As shown in the figure, it includes a rectangular plate-shaped base 64a, an insertion hole 64b penetrating the base 64a, and a convex portion 64c that surrounds the edge of the base 64a in a ring shape and protrudes in a direction away from the cover 52. The positive terminal 41 is accommodated in the space formed by the base 64a and the convex portion 64c of the positive electrode side second insulating plate 64. The insertion portion 41b of the positive terminal 41 is inserted into the insertion hole 64b. The positive electrode side second insulating plate 64 is formed of, for example, an insulating resin.

[0073] The negative electrode side second insulating plate 65 is, for example, Figure 3 As shown in FIG. 4 , the negative electrode terminal 42 is insulated from the cover 52. The negative electrode side second insulating plate 65 is, for example, Fig.11 As shown in the figure, it includes a rectangular plate-shaped base 65a, an insertion hole 65b penetrating the base 65a, and a convex portion 65c that surrounds the edge of the base 65a in a ring shape and protrudes in a direction away from the cover 52. The negative terminal 42 is accommodated in the space formed by the base 65a and the convex portion 65c of the negative-side second insulating plate 65. The insertion portion 42b of the negative terminal 42 is inserted into the insertion hole 65b. The negative-side second insulating plate 65 is formed of, for example, an insulating resin.

[0074] The sealing body 70 seals the structural members of the battery 1 and the exterior body 50 . Figures 2 to 5 , Fig.11 as well as Fig.13 The sealing body 70 shown includes a positive electrode side gasket 71 and a negative electrode side gasket 72 .

[0075] The positive electrode side gasket 71 is, for example, Figure 5 As shown in FIG. 1 , the positive electrode side second insulating plate 64 is insulated from the cover 52. The positive electrode side gasket 71 is formed in a cylindrical shape. Fig.13 As shown, it includes: a first insertion portion 71a having a relatively large outer diameter; a second insertion portion 71b connected to the first insertion portion 71a and having a relatively small outer diameter; and an insertion hole 71c that penetrates the first insertion portion 71a and the second insertion portion 71b. The first insertion portion 71a of the positive electrode side gasket 71 is inserted into the insertion hole 64b of the positive electrode side second insulating plate 64. The second insertion portion 71b of the positive electrode side gasket 71 is inserted into the positive electrode side insertion hole 52a of the cover 52. The insertion portion 41b of the positive terminal 41 is inserted into the insertion hole 71c. The positive electrode side gasket 71 is formed of, for example, rubber having insulation and elasticity.

[0076] The negative electrode side gasket 72 is, for example, Figure 3 As shown in FIG. 1 , the negative electrode side second insulating plate 65 is insulated from the cover 52. The negative electrode side gasket 72 is formed in a cylindrical shape. Fig.11As shown in FIG. 1 , the first insertion portion 72a includes: a first insertion portion 72a having a relatively large outer diameter; a second insertion portion 72b connected to the first insertion portion 72a and having a relatively small outer diameter; and an insertion hole 72c penetrating the first insertion portion 72a and the second insertion portion 72b. The first insertion portion 72a of the negative electrode side gasket 72 is inserted into the insertion hole 65b of the negative electrode side second insulating plate 65. The second insertion portion 72b of the negative electrode side gasket 72 is inserted into the negative electrode side insertion hole 52b of the cover 52. The insertion portion 42b of the negative terminal 42 is inserted into the insertion hole 72c. The negative electrode side gasket 72 is formed of, for example, rubber having insulation and elasticity.

[0077] Regarding the method for manufacturing the battery 1, refer to Fig.14 The winding device 600 includes a controller 601, a delivery roller 602, a driven roller 603, a first conveying roller 604, a second conveying roller 605, a first camera 606, a first adjustment roller 607, a first driven roller 608, a cutting section 609, a cutting section base 610, a second camera 611, a second adjustment roller 612, a second driven roller 613, and a winding spindle 614.

[0078] The winding device 600 is provided with a first winding roll 503 around which the positive electrode sheet substrate 11K is wound and a second winding roll 504 around which the negative electrode sheet substrate 12K is wound.

[0079] The positive electrode sheet 11 is wound by the winding device 600 to form the charge-discharge body 10. The controller 601 controls the actions of the first winding roller 503, the second winding roller 504, the delivery roller 602, the first conveying roller 604, the second conveying roller 605, the first camera 606, the first adjustment roller 607, the cutting unit 609, the second camera 611, the second adjustment roller 612, and the winding spindle 614.

[0080] The first adjustment roller 607 and the first driven roller 608 are arranged between the delivery roller 602 and the first winding roller 503. The first camera 606 is arranged near the first adjustment roller 607. The second adjustment roller 612 and the second driven roller 613 are arranged between the delivery roller 602 and the second winding roller 504. The second camera 611 is arranged near the second adjustment roller 612. The cutting section 609 and the cutting section base 610 are arranged between the delivery roller 602 and the winding spindle 614.

[0081] The controller 601 operates the delivery roller 602. As the delivery roller 602 operates, the positive electrode sheet substrate 11K conveyed from the first winding roller 503, the separator substrate 13K conveyed from the first conveying roller 604, the negative electrode sheet substrate 12K conveyed from the second winding roller 504, and the separator substrate 13K conveyed from the second conveying roller 605 move toward the cutting section 609 and the cutting section base 610. The positive electrode sheet substrate 11K, the separator substrate 13K, the negative electrode sheet substrate 12K, and the separator substrate 13K are stacked in this order and move toward the cutting section 609 and the cutting section base 610 while being sandwiched by the delivery roller 602 and the driven roller 603.

[0082] The controller 601 activates the first camera 606 to photograph the positive electrode substrate 11K. Based on the photographed image of the positive electrode substrate 11K, the controller 601 determines whether the position of the positive electrode current collecting tab 11b formed on the positive electrode substrate 11K is at a position corresponding to the position where the positive electrode sheet 11 in the charge-discharge body 10 is first wound.

[0083] When the controller 601 determines that the position of the positive electrode current collector tab 11b is not at the corresponding position, it determines that the position of the positive electrode current collector tab 11b of the positive electrode sheet substrate 11K is offset, and adjusts the position of the positive electrode current collector tab 11b. The controller 601 operates the first adjustment roller 607 to move the positive electrode sheet substrate 11K sandwiched by the first adjustment roller 607 and the first driven roller 608 toward the cutting section 609 and the cutting section base 610. After the position of the positive electrode current collector tab 11b of the positive electrode sheet substrate 11K is adjusted by the first adjustment roller 607, a surplus portion protruding from the delivery roller 602 and the driven roller 603 is generated on the positive electrode sheet substrate 11K.

[0084] The controller 601 operates the cutting unit 609 to cut off the remaining portion of the positive electrode sheet substrate 11K together with the cutting unit base 610. Under the control of the controller 601, the positive electrode current collecting tab 11b corresponding to the first winding position is used as a mark to adjust the first winding position of the positive electrode sheet substrate 11K relative to the charge-discharge body 10.

[0085] The controller 601 operates the second camera 611 to photograph the negative electrode sheet substrate 12K. Based on the photographed image of the negative electrode sheet substrate 12K, the controller 601 determines whether the position of the negative electrode current collecting tab 12b formed on the negative electrode sheet substrate 12K is at a position corresponding to the position where the negative electrode sheet 12 in the charge-discharge body 10 is first wound. If the controller 601 determines that the position of the negative electrode current collecting tab 12b is not at the corresponding position, it determines that the position of the negative electrode current collecting tab 12b of the first winding of the negative electrode sheet substrate 12K is offset, and adjusts the position of the negative electrode current collecting tab 12b.

[0086] The controller 601 operates the second adjustment roller 612 to move the negative electrode sheet substrate 12K sandwiched by the second adjustment roller 612 and the second driven roller 613 toward the cutting section 609 and the cutting section base 610. After the position of the negative electrode current collector tab 12b of the first winding of the negative electrode sheet substrate 12K is adjusted by the second adjustment roller 612, a remaining portion protruding from the delivery roller 602 and the driven roller 603 is generated in the negative electrode sheet substrate 12K. The controller 601 operates the cutting section 609 to cut off the remaining portion of the negative electrode sheet substrate 12K together with the cutting section base 610. Through the control of the above-mentioned controller 601, the negative electrode current collector tab 12b corresponding to the first winding position is used as a mark to adjust the first winding position of the negative electrode sheet substrate 12K relative to the charge-discharge body 10.

[0087] The controller 601 operates the delivery roller 602 to deliver the stacked positive electrode sheet substrate 11K, the separator substrate 13K, the negative electrode sheet substrate 12K, and the separator substrate 13K toward the winding spindle 614. The controller 601 operates the winding spindle 614 to wind the stacked positive electrode sheet substrate 11K, the separator substrate 13K, the negative electrode sheet substrate 12K, and the separator substrate 13K.

[0088] The positive electrode sheet substrate 11K, the separator substrate 13K, the negative electrode sheet substrate 12K, and the separator substrate 13K are wound by the winding spindle 614 so as to constitute a charging and discharging body 10. The controller 601 operates the cutting unit 609 to cut off the ends of the wound positive electrode sheet substrate 11K, the separator substrate 13K, the negative electrode sheet substrate 12K, and the separator substrate 13K.

[0089] Thereafter, the charge / discharge body 10 is removed from the winding spindle 614. The charge / discharge body 10 is housed in the container 51. The lid 52 is joined to the container 51. The electrolyte 14 is injected from the injection hole 52c of the lid 52 toward the container 51. The electrolyte 14 is impregnated into the separator 13. The sealing plug 53 is joined to the injection hole 52c of the lid 52.

[0090] According to the embodiment described above, the following battery is realized. The first battery is a battery having an electrode body (charge-discharge body 10) formed by stacking a positive electrode sheet 11 and a negative electrode sheet 12, wherein the positive electrode sheet has: a positive electrode collector layer 11S having a positive electrode collector foil body 11a and a positive electrode collector tab 11b protruding from an edge end 11c in the width direction of the positive electrode collector foil body; a positive electrode active material layer 11T stacked on the positive electrode collector foil body except for an edge region 720 in the width direction of the positive electrode collector foil body; and a heat-resistant layer 11Q stacked on the edge region, the base region 710 of the positive electrode collector tab, and the positive electrode active material layer. According to the first battery, a battery in which the electrode collector tab of the positive electrode sheet does not deform can be provided.

[0091] The second battery is, in the first battery, characterized in that the heat-resistant layer is stacked on the edge area and the base area of ​​the positive electrode collector ear. The third battery is characterized in that, in the first battery, the edge area and the base area of ​​the positive electrode collector ear are filled with an insulating layer, and the heat-resistant layer is stacked on the insulating layer.

[0092] The fourth battery is any one of the first to third batteries, characterized in that the negative electrode sheet has a negative electrode collector layer 12S and a negative electrode active material layer 12T, the negative electrode collector layer 12S has a negative electrode collector foil body 12a and a negative electrode collector tab 12b protruding from an edge 12c in the width direction of the negative electrode collector foil body in the same direction as or in the opposite direction to the positive electrode collector tab, the negative electrode active material layer 12T is laminated to the edge of the negative electrode collector foil body, and the edge 12c of the negative electrode collector foil body and the edge 12Ta of the negative electrode active material layer are located within the range of the edge region. According to the fourth battery, the edge position of the electrode where metal burrs are likely to appear (the edge 12c of the negative electrode collector foil body 12a) is located at a position closer to the inside of the sheet in the width direction than the edge 11c of the positive electrode collector foil body 11a, so that short circuit can be suppressed.

[0093] The fifth battery is any one of the first to fourth batteries, wherein the positive electrode sheet and the negative electrode sheet are stacked with a separator 13 interposed therebetween, and an edge 13a of the separator in the width direction is located outside the edge 11c of the positive electrode current collector foil body in the width direction. According to the fifth battery, short circuit can be prevented.

[0094] The sixth battery is any one of the first to fifth batteries, characterized in that it has an external terminal 40 and a current collector 20 connected to the external terminal, the positive electrode current collector tab has a joint portion 760 joined to the current collector and a rounded portion 740 connected from the joint portion to the edge of the positive electrode current collector foil body, and the base region is a region within two times the distance from the edge of the positive electrode current collector foil body to the terminal end of the rounded portion in the protruding direction of the positive electrode current collector tab. According to the sixth battery, the area of ​​the positive electrode current collector tab 11b exposed from the heat-resistant layer 11Q can be sufficiently ensured to avoid poor welding between the positive electrode current collector tab 11b and the current collector 20.

[0095] The manufacturing method of the battery having the electrode body is to manufacture the electrode body by winding and stacking the positive electrode sheet 11 and the negative electrode sheet 12 of the first to sixth batteries via the separator 13. According to this manufacturing method, a battery in which the electrode current collecting tab of the positive electrode sheet is not deformed can be manufactured.

[0096] The battery of the present invention is not limited to the structure described in the embodiment, and can be appropriately configured based on the contents described in the claims.

[0097] The battery of the present invention is not limited to lithium-ion batteries. The battery of the present invention can be applied to nickel-metal hydride batteries and lead batteries, for example. The battery of the present invention is not limited to secondary batteries. The battery of the present invention can be applied to primary batteries. The battery of the present invention is not limited to a structure in which a charge and discharge body is sealed with a container and a cover. The battery of the present invention can be applied to a structure in which a charge and discharge body is sealed with a laminated film. Each embodiment is only a way of describing the present invention in detail or briefly to make it easier to understand, and does not necessarily include all the structures described, and may also include structures not shown. In addition, a part of the structure of an embodiment may be deleted and replaced with the structure of other embodiments, or the structures of other embodiments may be combined.

[0098] Description of Reference Numerals 1: battery, 10: charging and discharging body (battery body), 11: positive electrode sheet, 11Q: heat-resistant layer, 11R: insulating layer, 11S: positive electrode collector layer, 11T: positive electrode active material layer, 11Ta: edge of positive electrode active material layer, 11a: positive electrode collector foil body, 11b: positive electrode collector ear, 11c: edge of positive electrode collector foil body, 12: negative electrode sheet, 12S: negative electrode collector layer, 12T: negative electrode active material layer, 12Ta: edge of negative electrode active material layer, 12a: negative electrode collector foil body, 12b: negative electrode collector ear, 12c: edge of negative electrode collector foil body, 13: separator, 13a: edge of separator, 14: electrolyte, 20: collector, 740: fillet shape portion, 760: joint portion.

Claims

1. A battery having an electrode body formed by stacking a positive electrode sheet and a negative electrode sheet, wherein: The positive electrode sheet has: The positive electrode current collecting layer comprises a positive electrode current collecting foil main body and a positive electrode current collecting tab protruding from an edge in a width direction of the positive electrode current collecting foil main body; A positive electrode active material layer is laminated on the positive electrode current collector foil body except for the edge region in the width direction of the positive electrode current collector foil body; as well as The heat-resistant layer is laminated on the edge region, the base region of the positive electrode current collecting tab, and the positive electrode active material layer.

2. The battery according to claim 1, wherein The heat-resistant layer is laminated on the edge region and the base region of the positive electrode current collecting tab.

3. The battery according to claim 1, wherein An insulating layer is stacked on the edge region and the base region of the positive electrode current collecting tab, and the heat-resistant layer is stacked on the insulating layer.

4. The battery according to any one of claims 1 to 3, wherein The negative electrode sheet has: A negative electrode current collecting layer comprises a negative electrode current collecting foil body and a negative electrode current collecting tab protruding from the edge of the negative electrode current collecting foil body in the width direction in the same direction as or in the opposite direction to the positive electrode current collecting tab, and A negative electrode active material layer, laminated to the edge of the negative electrode current collector foil body; The edge ends of the negative electrode current collector foil body and the negative electrode active material layer are located within the range of the edge region.

5. The battery according to any one of claims 1 to 3, wherein The positive electrode sheet and the negative electrode sheet are stacked with a separator therebetween. An edge of the separator in the width direction is located outside the edge of the positive electrode current collector foil body in the width direction.

6. The battery according to any one of claims 1 to 3, wherein The battery has an external terminal and a current collector connected to the external terminal. The positive electrode current collector tab has a joint portion joined to the current collector and a rounded portion connected from the joint portion to the edge of the positive electrode current collector foil body. The base region is a region within twice the distance from the edge of the positive electrode current collecting foil body to the terminal end of the fillet-shaped portion in the protruding direction of the positive electrode current collecting tab.

7. A method for manufacturing a battery, the battery having an electrode body, wherein: The electrode body is produced by winding the positive electrode sheet and the negative electrode sheet according to any one of claims 1 to 3 and stacking them with a separator interposed therebetween.

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