Battery and method for manufacturing a battery

Abstract

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

Description

Technical Field

[0006] , , ,

[0005] , ,

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

Background Art

[0002] Conventionally, a secondary battery in which a plurality of terminal portions (electrode current collector tabs) are formed on a wound electrode sheet has been known. Patent Document 1 discloses a positive electrode sheet in which a positive electrode current collector tab protrudes from an end portion in the width direction of a metal foil. In the positive electrode sheet, there is a region where no positive electrode active material is formed in the edge region in the width direction of the metal foil, and an insulating layer is formed on this region and the base portion of the positive electrode current collector tab closer to the metal foil. This insulating layer can reinforce the base portion of the positive electrode current collector tab where stress is likely to concentrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the positive electrode sheet of the above-described secondary battery, due to the difference in elongation rate between the active material layer and the insulating layer, there is room to reduce the occurrence of deformation such as wrinkles and warping in the vicinity of the root of the electrode current collector tab during roll pressing after coating the metal foil with the active material, or when winding the positive electrode sheet, the negative electrode sheet, and the separator to form an electrode body. <​​​​​​​To achieve the above objective, the present invention provides a battery comprising a charge / discharge body in which a positive electrode sheet and a negative electrode sheet are laminated, wherein the positive electrode sheet comprises a positive electrode current collector layer having a positive electrode current collector foil body and a positive electrode current collector tab protruding from the widthwise edge of the positive electrode current collector foil body, a positive electrode active material layer laminated on the positive electrode current collector foil body excluding the widthwise edge region of the positive electrode current collector foil body, and a heat-resistant layer laminated on the edge region, the base region of the positive electrode current collector tab and the positive electrode active material layer.

[0007] Furthermore, the present invention relates to a method for manufacturing a battery equipped with an electrode body, wherein the electrode body is created by winding and stacking the aforementioned positive electrode sheet and negative electrode sheet with a separator in between. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a battery in which deformation does not occur in the electrode current collecting tab of the positive electrode sheet, and a method for manufacturing the battery. [Brief explanation of the drawing]

[0009] [Figure 1] A perspective view showing battery 1. [Figure 2] A cross-sectional perspective view showing the area around the negative terminal 42 of battery 1. [Figure 3] A cross-sectional view showing the area around the negative terminal 42 of battery 1. [Figure 4] A cross-sectional perspective view showing the area around the positive terminal 41 of battery 1. [Figure 5] A cross-sectional view showing the area around the positive terminal 41 of battery 1. [Figure 6] An exploded perspective view showing battery 1. [Figure 7] A perspective view showing the charge / discharge unit 10 of battery 1. [Figure 8A] Plan view of the positive electrode sheet 11. [Figure 8B] A cross-sectional view of the positive electrode sheet 11 in the short direction (width direction: Z-axis direction) as seen from the 8B direction. [Figure 8C] Cross-section of the second embodiment of the positive electrode sheet 11. [Figure 9A] A cross-sectional view showing an example of a structure in which a negative electrode sheet 12 is wound and stacked on a positive electrode sheet 11 shown in FIG. 8A via a separator 13. [Figure 9B] A cross-sectional view showing an example of a structure in which a negative electrode sheet 12 is wound and stacked on a positive electrode sheet 11 shown in FIG. 8B via a separator 13. [Figure 10] A perspective view showing the electrodes (positive electrode sheet 11 and negative electrode sheet 12) and the separator 13 of the battery 1. [Figure 11] An exploded perspective view showing the periphery of the negative electrode terminal 42 of the battery 1. [Figure 12] An exploded perspective view showing the lid 52 and the sealing plug 53 of the battery 1. [Figure 13] An exploded perspective view showing the periphery of the positive electrode terminal 41 of the battery 1. [Figure 14] A perspective view showing a method of manufacturing current collecting foils (positive electrode current collecting layer 11S and negative electrode current collecting layer 12S) of the electrodes (positive electrode sheet 11 and negative electrode sheet 12) of the battery 1.

Embodiments for Carrying Out the Invention

[0010] The configuration of the battery 1 according to the first embodiment will be described with reference to the drawings. The battery 1 includes, for example, as shown in FIGS. 1 to 5, a charge and discharge body (electrode body) 10 that charges and discharges electricity, a current collector 20 connected to the charge and discharge body 10, a current cut-off body 30 connected to the current collector 20, an external terminal 40 connected to the current collector 20 or the current cut-off body 30, and an exterior body 50 in which the constituent members of the battery 1 are housed or attached. Further, the battery 1 includes an insulator 60 that insulates the constituent members of the battery 1 from the exterior body 50, and a sealing body 70 that seals the constituent members of the battery 1 and the exterior body 50.

[0011] The charge and discharge body 10 charges and discharges electricity. The charge and discharge body 10 shown in FIGS. 2 to 7 includes a positive electrode 11, a negative electrode 12, a separator 13 (insulating member), and an electrolyte 14. As shown in FIG. 7, the charge and discharge body 10 is configured by winding constituent members laminated in the order of the positive electrode 11, the separator 13, the negative electrode 12, and the separator 13 in a rectangular parallelepiped shape.

[0012] As shown in, for example, FIG. 7, the positive electrode sheet 11 includes a positive electrode current collector layer 11S (current collector foil) made of a sheet-like metal foil, and a positive electrode active material layer 11T laminated and joined to the positive electrode current collector layer 11S. The positive electrode current collector layer 11S includes a positive electrode current collector foil main body 11a and a positive electrode current collector tab 11b. The positive electrode current collector foil main body 11a is wound. The positive electrode active material layer 11T is laminated and joined to the positive electrode current collector foil main body 11a.

[0013] As shown in, for example, FIG. 7, the positive electrode current collector tab 11b (terminal portion) protrudes in the width direction from the edge 11c in the width direction (the short side direction of the positive electrode current collector foil main body 11a) along the longitudinal direction (winding direction) of the positive electrode current collector foil main body 11a. The positive electrode current collector tab 11b is integrally formed with the positive electrode current collector foil main body 11a. A plurality of positive electrode current collector tabs 11b are formed on one positive electrode current collector foil main body 11a.

[0014] Here, regarding the interval between adjacent positive electrode current collector tabs 11b along the winding direction, any configuration may be adopted as long as it includes a positive electrode current collector tab 11b whose adjacent interval is relatively long from one end portion 11p (FIG. 10) to the other end portion 11q of the positive electrode current collector foil main body 11a. That is, it is not limited to a configuration in which, for all the positive electrode current collector tabs 11b, the interval between adjacent positive electrode current collector tabs 11b along the winding direction is relatively long from one end portion 11p to the other end portion 11q of the positive electrode current collector foil main body 11a. For example, the adjacent positive electrode current collector tabs 11b along the winding direction may be configured such that an equal pitch and an unequal pitch are alternately repeated from one end portion 11p to the other end portion 11q of the positive electrode current collector foil main body 11a.

[0015] 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 aid, and the like. For the lithium-containing composite oxide, metal elements such as nickel (Ni), cobalt (Co), and manganese (Mn) and lithium (Li) are used.

[0016] The negative electrode sheet 12 includes, for example, a negative electrode current collector layer 12S (current collector foil) made of a sheet-like metal foil, and a negative electrode active material layer 12T laminated and bonded to the negative electrode current collector layer 12S, as shown in Figure 7. The negative electrode current collector layer 12S includes a negative electrode current collector foil body 12a and a negative electrode current collector tab 12b. The negative electrode active material layer 12T is laminated and bonded to the negative electrode current collector foil body 12a. The negative electrode active material layer 12T faces, for example, the entire area along the short side direction (Z-axis direction) of the negative electrode current collector foil body 12a.

[0017] The negative electrode current collector tab 12b (terminal portion) protrudes from the edge 12c along the longitudinal direction (winding direction) of the negative electrode current collector foil body 12a in the short direction of the negative electrode current collector foil body 12a, as shown in Figure 7, for example. When the negative electrode current collector tab 12b is laminated with the positive electrode sheet 11 via the separator 13, it protrudes in the same direction as the positive electrode current collector tab 11b of the positive electrode sheet 11. When the negative electrode current collector tab 12b is laminated with the positive electrode sheet 11 via the separator 13, it is separated from the positive electrode current collector tab 11b of the positive electrode sheet 11. The negative electrode current collector tab 12b is formed integrally with the negative electrode current collector foil body 12a. Multiple negative electrode current collector tabs 12b are formed on one negative electrode current collector foil body 12a.

[0018] The negative electrode current collector tabs 12b, like the positive electrode current collector tabs 11b, are configured with a so-called unequal pitch. That is, the spacing between adjacent negative electrode current collector tabs 12b along the winding direction is relatively longer for negative electrode current collector tabs 12b closer to the other end 12q of the negative electrode current collector foil body 12a where winding ends, than for negative electrode current collector tabs 12b closer to the first end 12p (Figure 10) of the negative electrode current collector foil body 12a where winding begins. All negative electrode current collector tabs 12b overlap when the negative electrode current collector foil body 12a is wound. Here, regarding the spacing of the negative electrode current collector tabs 12b, it is sufficient to include negative electrode current collector tabs 12b in which the spacing between adjacent tabs is relatively longer as you move from the first end 12p to the other end 12q of the negative electrode current collector foil body 12a, similar to the spacing of the positive electrode current collector tabs 11b.

[0019] The metal foil of the negative electrode current collector 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 composed of a carbon-based material, a binder, and a conductive additive. For example, graphite is used as the carbon-based material.

[0020] The separator 13 (insulator), as shown in Figure 7 for example, insulates between the positive electrode sheet 11 and the negative electrode sheet 12 while allowing lithium ions to pass through. The separator 13 is formed in a sheet shape. The separator 13 has a longer width in the shorter direction (Z-axis direction) compared to the positive electrode current collector foil body 11a of the positive electrode sheet 11 and the negative electrode current collector foil body 12a of the negative electrode sheet 12. Both ends of the positive electrode current collector foil body 11a of the positive electrode sheet 11 and both ends of the negative electrode current collector foil body 12a of the negative electrode sheet 12 are located within the range of the separator 13 in the shorter direction. The separator 13 is made of a porous material. Polyethylene (PE) or polypropylene (PP) are used for the separator 13. A heat-resistant insulating material may be used instead of the separator 13. For example, ceramics can be used for the heat-resistant insulating material. This type of configuration is what is known as a separator-less configuration.

[0021] The electrolyte 14 corresponds to a so-called electrolyte solution. The electrolyte 14 is impregnated into 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 be replaced with a sheet-like solid electrolyte.

[0022] Figure 8A is a plan view of the positive electrode sheet 11, and Figure 8B is a cross-sectional view of the positive electrode sheet 11 in the short direction (width direction: Z-axis direction) as seen from the 8B direction. In Figure 8A, the heat-resistant layer 11Q shown in Figure 8B is omitted. The positive electrode active material layer 11T is laminated on the positive electrode current collector foil body 11a, excluding the edge region 720 of a predetermined width from the edge 11c on the positive electrode current collector tab 11b side, within the entire area of ​​both sides of the positive electrode current collector foil body 11a. The edge region 720 is the area between the short-direction edge 11Ta of the positive electrode active material layer 11T and the short-direction edge 11c of the positive electrode current collector foil body 11a (for example, 2-6 mm). The arrows with labels indicate the Z-axis direction.

[0023] The positive electrode current collector tab 11b has a joint portion 760 that is welded and connected to the current collector 20 connected to the external terminal 40, and a rounded portion 740 that extends from the joint portion 760 to the edge 11c of the positive electrode current collector foil body 11a. Reference numeral 710 denotes the base region of the positive electrode current collector tab 11b. The base region 710 is the 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 tip end of the positive electrode current collector tab 11b.

[0024] As an example, the width of the edge region 720 is less than or equal to the width of the base region 710. This allows for maximum utilization of the positive electrode active material layer 11T. This is preferable from the viewpoint of improving battery input / output. As another example, the width of the edge region 720 is greater than the width of the base region 710. This allows for a wider width between the active material layer 11T and the edge 11c, so that the layer can be stably formed in this region.

[0025] A heat-resistant layer 11Q is laminated over the entire area of ​​the positive electrode active material layer 11T and over the area 700 which is a combination of the edge area 720 and the base area 710. After the positive electrode active material layer 11T and the heat-resistant layer 11Q are created on the positive electrode current collector foil body 11a, the body is pressed with a press roll, and the positive electrode current collector tab 11b is formed by pressing, cutting, or laser processing to obtain the positive electrode sheet 11 shown in Figure 8B.

[0026] When the positive electrode sheet, negative electrode sheet, and separator are wound together, a heat-resistant layer is placed between the separator and the positive electrode active material layer. To avoid reducing the battery reaction, the structure required for the heat-resistant layer is to allow lithium ions in the electrolyte to pass through easily. Therefore, the heat-resistant layer can be made of a porous material with a porous structure. For example, a ceramic coating. Regarding the thickness of the heat-resistant layer, if battery performance (emphasis on reaction) is prioritized, a thinner heat-resistant layer is advantageous, while conversely, if safety is prioritized, a thicker heat-resistant layer is preferable.

[0027] As shown in Figure 8B, the positive electrode sheet 11 is uniformly covered by the heat-resistant layer 11Q, as is the active material layer 11T, the edge region 720 of the positive electrode current collector foil body 11a, and the base region 710 of the positive electrode current collector tab 11b. This eliminates the problem of differences in elongation rates. Therefore, when the positive electrode sheet 11 is wound to form the charge / discharge body 10, deformation such as bending, warping, and wrinkling of the positive electrode current collector tab 11b is suppressed, improving the connection between the positive electrode current collector tab 11b and the current collector 20, and eliminating poor conductivity.

[0028] The tip of the base region 710 is preferably set to be within twice the distance (760) from the edge 11c of the positive electrode current collector foil body 11a to the end of the protruding positive electrode current collector tab 11b of the rounded portion 740. By doing so, a sufficient area of ​​the positive electrode current collector tab 11b is exposed from the heat-resistant layer 11Q, thereby avoiding welding defects between the positive electrode current collector tab 11b and the current collector 20.

[0029] Figure 8C shows a second embodiment of the positive electrode sheet 11. In the embodiment of Figure 8B, a heat-resistant layer 11Q is laminated in region 700, whereas in the embodiment of Figure 8C, an insulating layer 11R is laminated in region 700 instead of the heat-resistant layer 11Q. The heat-resistant layer 11Q is laminated on the positive electrode active material layer 11T and the insulating layer 11R. The rigidity of the positive electrode current collector tab 11b is increased by the insulating layer 11R.

[0030] The insulating layer 11R comprises at least an insulating material and a binder. The insulating material includes at least one selected from, for example, aluminum oxide (e.g., α-alumina), silica, acrylic resin, magnesia, calcia, titania, zirconia, boehmite, and magnesium hydroxide. The binder comprises at least styrene-butadiene rubber and at least one selected from carboxymethylcellulose and its salts.

[0031] Figure 9A is a cross-sectional view showing an example of a structure in which a negative electrode sheet 12 is wound around and stacked on a positive electrode sheet 11 shown in Figure 8A via a separator 13. Figure 9B is a cross-sectional view showing an example of a structure in which a negative electrode sheet 12 is wound around and stacked on a positive electrode sheet 11 shown in Figure 8B via a separator 13. The negative electrode active material layer 12T is laminated over the entire area on 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.

[0032] Furthermore, the edge 12c of the negative electrode current collector foil body 12a has a shorter width in the shorter direction (Z-axis direction) compared to the edge 11c of the positive electrode current collector foil body 11a of the positive electrode sheet 11. The edge 12c of the negative electrode current collector foil body 12a is located within the edge region 720 between the edge 11c of the positive electrode current 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 electrode edge where metal burrs are likely to form (edge ​​12c of the electrode current collector foil body 12a) is located inward in the width direction of the sheet compared to the edge 11c of the positive electrode current collector foil body 11a, thereby suppressing short circuits. In addition, the widthwise edge 13a of the separator 13 is located outside the widthwise edge 11c of the positive electrode current collector foil body 11a. This prevents short circuits.

[0033] Although an example has been described in which the negative electrode current collector tab 12b protrudes in the same direction as the positive electrode current collector tab 11b, the current collector tab 12b may also protrude in the opposite direction to the positive electrode current collector tab 11b. In Figures 9A and 9B, 12c and 12Ta indicate the end faces opposite to the side from which the negative electrode current collector tab 12b protrudes.

[0034] The current collector 20 is connected to the charge / discharge unit 10. The current collector 20 shown in Figures 2 to 5, 11 and 13 includes a positive electrode current collector plate 21 and a negative electrode current collector plate 22.

[0035] The positive electrode current collector plate 21, as shown in Figures 4 and 5, for example, connects the positive electrode current collector tab 11b of the charge / discharge body 10 with the positive electrode terminal 41 via a current interrupter 30. The positive electrode current collector plate 21 includes, as shown in Figure 13, for example, a rectangular plate-shaped first base portion 21a, a rectangular plate-shaped second base portion 21b, and a connecting portion 21c that connects the first base portion 21a and the second base portion 21b in a stepped manner with different heights. A recess 21d is formed on the upper surface (the surface on the positive Z-axis side) of the second base portion 21b, where the thickness of the second base portion 21b is made thinner. A ring-shaped recessed weak portion, the weak portion 21e, is formed in the center of the recess 21d. The positive electrode current collector plate 21 is made of, for example, aluminum or an aluminum alloy.

[0036] The negative electrode current collector plate 22 connects the negative electrode current collector tab 12b of the charge / discharge unit 10 with the negative electrode terminal 42, as shown in Figures 2 and 3, for example. The negative electrode current collector plate 22 includes a rectangular plate-shaped base 22a and an insertion hole 22b that penetrates the base 22a, as shown in Figure 11, for example. The insertion portion 42b of the negative electrode terminal 42 is inserted into the insertion hole 22b of the negative electrode current collector plate 22. The negative electrode current collector plate 22 is made of, for example, copper or a copper alloy.

[0037] The current interrupter 30 is connected to the current collector 20, and makes electrical contact between the current collector 20 and the positive terminal 41. The current interrupter 30 shown in Figures 4, 5 and 13 includes a diaphragm 31, a conductive member 32, and a pair of support bases 33.

[0038] The diaphragm 31 includes, for example, a curved cylindrical main body 31a, a disc-shaped first joining portion 31b provided on the tip side (negative Z-axis side) of the main body 31a, and a ring-shaped second joining portion 31c provided on the base side (positive Z-axis side) of the main body 31a. The first joining portion 31b is joined to the recess 21d of the positive electrode current collector plate 21. The second joining portion 31c is joined to the conductive member 32. The diaphragm 31 is formed of, for example, aluminum or an aluminum alloy.

[0039] The conductive member 32 is formed in a cylindrical shape, as shown in Figure 13, for example. The upper surface (the surface on the positive Z-axis side) of the conductive member 32 is joined to the positive electrode side first insulating plate 62. The periphery of the lower surface (the surface on the negative Z-axis side) of the conductive member 32 is joined to the second joining portion 31c of the diaphragm 31. The conductive member 32 is formed of, for example, aluminum or an aluminum alloy.

[0040] The support base 33 includes, for example, a rectangular main body 33a extending in the short direction (Y-axis direction) of the battery 1, and legs 33b extending downward (negative Z-axis direction) from both sides of the main body 33a in the longitudinal direction (Y-axis direction). One support base 33 is provided at each end of the diaphragm 31 along the longitudinal direction (X-axis direction) of the battery 1. The main body 33a is attached to the positive electrode side first insulating plate 62. The legs 33b are attached to the second base 21b of the positive electrode current collector plate 21. The support base 33 is formed of, for example, an insulating resin.

[0041] The external terminal 40 is connected to the current collector 20 or the current interrupter 30. The external terminal 40 shown in Figures 1 to 6, 11 and 13 includes a positive terminal 41 and a negative terminal 42.

[0042] The positive terminal 41 is connected to the conductive member 32 of the current interrupter 30, for example, as shown in Figure 5. The positive terminal 41 includes a rectangular plate-shaped base 41a, a cylindrical insertion portion 41b protruding downward (in the negative Z-axis direction) from the base 41a, and a cylindrical joining portion 41c protruding downward (in the negative Z-axis direction) from the periphery of the base 41a.

[0043] The base portion 41a is in contact with the base portion 64a of the positive electrode side second insulating plate 64, for example, as shown in Figure 13. The insertion portion 41b is inserted into the insertion hole 64b of the positive electrode side second insulating plate 64, the positive electrode side insertion hole 52a of the cover 52, the insertion hole 62b of the positive electrode side first insulating plate 62, and the insertion hole 32b of the conductive member 32.

[0044] The joint portion 41c protrudes downward (in the negative Z-axis direction) from the insertion hole 32b of the conductive member 32, as shown in Figure 13, for example, and is expanded radially outward to join with the conductive member 32. That is, the joint portion 41c is crimped to the periphery of the insertion hole 32b of the conductive member 32. Furthermore, the joint 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.

[0045] The negative electrode terminal 42 is connected to the negative electrode current collector plate 22, for example, as shown in Figure 3. The negative electrode terminal 42 includes a rectangular plate-shaped base portion 42a, a cylindrical insertion portion 42b protruding downward (in the negative Z-axis direction) from the base portion 42a, and a cylindrical joining portion 42c protruding downward (in the negative Z-axis direction) from the periphery of the base portion 42a.

[0046] The base portion 42a is in contact with the base portion 65a of the negative electrode side second insulating plate 65, for example, as shown in Figure 11. 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 current collector plate 22.

[0047] The joint portion 42c protrudes downward from the insertion hole 22b of the negative electrode current collector plate 22, as shown in Figure 11, for example, and is expanded radially outward to join with the negative electrode current collector plate 22. That is, the joint portion 42c is crimped to the periphery of the insertion hole 22b of the negative electrode current collector plate 22. Furthermore, the joint portion 42c is welded to the periphery of the insertion hole 22b of the negative electrode current collector plate 22. The negative electrode terminal 42 is formed of, for example, copper or a copper alloy.

[0048] The outer casing 50 houses or mounts the components of the battery 1. The outer casing 50 shown in Figures 1 to 6 and Figures 11 to 13 includes a container 51, a lid 52, and a sealing plug 53.

[0049] The container 51 houses a charge / discharge unit 10 covered by an insulating cover 61, as shown in Figures 2 and 6, for example. The container 51 is made of a rectangular metal can. The container 51 includes an opening 51a that opens along the longitudinal direction and a housing section 51b connected to the opening 51a, as shown in Figure 6, for example. The container 51 is made of aluminum or an aluminum alloy, for example.

[0050] The lid 52 seals the opening 51a of the container 51, as shown in Figures 2 and 6, for example. The lid 52 faces one side 10a (side portion) of the charge / discharge body 10 where the positive electrode sheet 11, separator 13, and negative electrode sheet 12 are adjacent. The lid 52 is formed from a long, plate-shaped metal sheet. The lid 52 has a positive electrode side insertion hole 52a, which is a circular through hole, at one end in the longitudinal direction. The insertion portion 41b of the positive electrode terminal 41 is inserted into the positive electrode side insertion hole 52a. The lid 52 has a negative electrode side insertion hole 52b, which is a circular through hole, at the other end in the longitudinal direction. The insertion portion 42b of the negative electrode terminal 42 is inserted into the negative electrode side insertion hole 52b.

[0051] The lid 52 has an injection hole 52c formed by a circular through-hole between the positive electrode side insertion hole 52a and the negative electrode side insertion hole 52b. The electrolyte 14 is injected from the lid 52 toward the container 51 through the injection hole 52c. The insertion portion 53b of the sealing plug 53 is inserted into the injection hole 52c. The lid 52 has a splitting valve 52d formed in the longitudinal center. The lid 52 is welded to the container 51. The lid 52 is made of, for example, aluminum or an aluminum alloy.

[0052] The sealing plug 53 seals the liquid injection hole 52c of the lid 52, for example, as shown in Figure 12. 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 that is continuous with the head 53a and has a relatively smaller outer diameter. The head 53a of the sealing plug 53 is welded to the lid 52. The sealing plug 53 is made of, for example, aluminum or an aluminum alloy.

[0053] The insulator 60 insulates the components of the battery 1 from the outer casing 50. The insulator 60 shown in Figures 2 to 6, 11 and 13 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.

[0054] The insulating cover 61 insulates the charge / discharge element 10 by covering it, as shown in Figure 6, for example. The insulating cover 61 has a pair of opposing sides (first side 61a and second side 61b) and an opening 61c between the first side 61a (one side) and the second side 61b (the other side) that exposes one side 10a of the charge / discharge element 10. The insulating cover 61 covers all sides of one side 10a of the charge / discharge element 10 except for one side. That is, the insulating cover 61 covers the other side 10b of the charge / discharge element 10 that is opposite to the first side 10a, and the outer periphery 10c located between the first side 10a and the other side 10b of the charge / discharge element 10. The insulating cover 61 is formed into a pentahedron shape by folding a polyhedron-shaped sheet into a box shape. The insulating cover 61 is made of, for example, polypropylene.

[0055] The positive electrode side first insulating plate 62 insulates the positive electrode current collector plate 21 and the conductive member 32 from the lid 52, as shown in Figure 5, for example. The positive electrode side first insulating plate 62 includes a rectangular plate-shaped base portion 62a, an insertion hole 62b that penetrates the base portion 62a, and a protrusion 62c that surrounds the edge of the base portion 62a in an annular shape and protrudes away from the lid 52, as shown in Figure 13, for example. The positive electrode side first insulating plate 62 houses the positive electrode current collector plate 21 and the conductive member 32, etc., in the space formed by the base portion 62a and the protrusion 62c. The insertion portion 41b of the positive electrode terminal 41 is inserted into the insertion hole 62b. The positive electrode side first insulating plate 62 is formed of, for example, an insulating resin.

[0056] The negative electrode side first insulating plate 63 insulates the negative electrode current collector plate 22 from the cover 52, as shown in Figure 3, for example. The negative electrode side first insulating plate 63 includes a rectangular plate-shaped base portion 63a, an insertion hole 63b that penetrates the base portion 63a, and a protrusion 63c that surrounds the edge of the base portion 63a in an annular shape and protrudes away from the cover 52, as shown in Figure 11, for example. The negative electrode current collector plate 22 is housed in the space formed by the base portion 63a and the protrusion 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.

[0057] The positive electrode side second insulating plate 64 insulates the positive electrode terminal 41 from the cover 52, as shown in Figure 5, for example. The positive electrode side second insulating plate 64 includes a rectangular plate-shaped base 64a, an insertion hole 64b that penetrates the base 64a, and a protrusion 64c that surrounds the edge of the base 64a in an annular shape and protrudes away from the cover 52, as shown in Figure 13, for example. The positive electrode terminal 41 is housed in the space formed by the base 64a and the protrusion 64c of the positive electrode side second insulating plate 64. The insertion portion 41b of the positive electrode 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.

[0058] The negative electrode side second insulating plate 65 insulates the negative electrode terminal 42 from the cover 52, as shown in Figure 3, for example. The negative electrode side second insulating plate 65 includes a rectangular plate-shaped base 65a, an insertion hole 65b that penetrates the base 65a, and a protrusion 65c that surrounds the edge of the base 65a in an annular shape and protrudes away from the cover 52, as shown in Figure 11, for example. The negative electrode terminal 42 is housed in the space formed by the base 65a and the protrusion 65c of the negative electrode side second insulating plate 65. The insertion portion 42b of the negative electrode terminal 42 is inserted into the insertion hole 65b. The negative electrode side second insulating plate 65 is formed of, for example, an insulating resin.

[0059] The sealing body 70 seals the components of the battery 1 and the outer casing 50. The sealing body 70 shown in Figures 2 to 5, 11 and 13 includes a positive electrode gasket 71 and a negative electrode gasket 72.

[0060] The positive electrode gasket 71 insulates the positive electrode second insulating plate 64 from the lid 52, as shown in Figure 5, for example. The positive electrode gasket 71 is formed in a cylindrical shape. The positive electrode gasket 71 includes a first insertion portion 71a with a relatively large outer diameter, a second insertion portion 71b that is continuous with the first insertion portion 71a and has a relatively smaller outer diameter, and an insertion hole 71c that penetrates the first insertion portion 71a and the second insertion portion 71b, as shown in Figure 13, for example. The first insertion portion 71a of the positive electrode gasket 71 is inserted into the insertion hole 64b of the positive electrode second insulating plate 64. The second insertion portion 71b of the positive electrode gasket 71 is inserted into the positive electrode insertion hole 52a of the lid 52. The insertion portion 41b of the positive electrode terminal 41 is inserted into the insertion hole 71c. The positive electrode gasket 71 is formed of, for example, rubber that has insulating and elastic properties.

[0061] The negative electrode gasket 72 insulates the negative electrode second insulating plate 65 from the lid 52, as shown in Figure 3, for example. The negative electrode gasket 72 is formed in a cylindrical shape. The negative electrode gasket 72 includes a first insertion portion 72a with a relatively large outer diameter, a second insertion portion 72b that is continuous with the first insertion portion 72a and has a relatively smaller outer diameter, and an insertion hole 72c that penetrates the first insertion portion 72a and the second insertion portion 72b, as shown in Figure 11, for example. The first insertion portion 72a of the negative electrode gasket 72 is inserted into the insertion hole 65b of the negative electrode second insulating plate 65. The second insertion portion 72b of the negative electrode gasket 72 is inserted into the negative electrode insertion hole 52b of the lid 52. The insertion portion 42b of the negative electrode terminal 42 is inserted into the insertion hole 72c. The negative electrode gasket 72 is formed of, for example, rubber that has insulating and elastic properties.

[0062] The manufacturing method for battery 1 will be described with reference to Figure 14. The winding device 600 includes a controller 601, a feed roller 602, a driven roller 603, a first discharge roller 604, a second discharge roller 605, a first camera 606, a first adjustment roller 607, a first driven roller 608, a cutter 609, a cutter support 610, a second camera 611, a second adjustment roller 612, a second driven roller 613, and a winding spindle 614.

[0063] The winding device 600 is equipped with a first winding roller 503 on which the positive electrode sheet substrate 11K is wound, and a second winding roller 504 on which the negative electrode sheet substrate 12K is wound.

[0064] The winding device 600 winds the positive electrode sheet 11 to form the charge / discharge body 10. The controller 601 controls the operation of the first winding roller 503, the second winding roller 504, the delivery roller 602, the first discharge roller 604, the second discharge roller 605, the first camera 606, the first adjustment roller 607, the cutter 609, the second camera 611, the second adjustment roller 612, and the winding spindle 614.

[0065] The first adjustment roller 607 and the first driven roller 608 are positioned between the feed roller 602 and the first winding roller 503. The first camera 606 is positioned near the first adjustment roller 607. The second adjustment roller 612 and the second driven roller 613 are positioned between the feed roller 602 and the second winding roller 504. The second camera 611 is positioned near the second adjustment roller 612. The cutter 609 and the cutter support 610 are positioned between the feed roller 602 and the winding spindle 614.

[0066] The controller 601 activates the delivery roller 602. As the delivery roller 602 is activated, the positive electrode sheet substrate 11K discharged from the first winding roller 503, the separator substrate 13K discharged from the first discharge roller 604, the negative electrode sheet substrate 12K discharged from the second winding roller 504, and the separator substrate 13K discharged from the second discharge roller 605 move toward the cutter 609 and the cutter support 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 that order and move toward the cutter 609 and the cutter support 610 while being sandwiched between the delivery roller 602 and the driven roller 603.

[0067] The controller 601 activates the first camera 606 to photograph the positive electrode sheet substrate 11K. Based on the image of the positive electrode sheet substrate 11K that has been photographed, the controller 601 determines whether the position of the positive electrode current collector tab 11b formed on the positive electrode sheet substrate 11K is at a position corresponding to the starting position of winding the positive electrode sheet 11 in the charge / discharge unit 10.

[0068] If the controller 601 determines that the positive electrode current collector tab 11b is not in the corresponding position, it determines that the position of the positive electrode current collector tab 11b at the start of winding the positive electrode sheet substrate 11K is misaligned 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, which is sandwiched between the first adjustment roller 607 and the first driven roller 608, toward the cutter 609 and the cutter support 610. After the position of the positive electrode current collector tab 11b at the start of winding the positive electrode sheet substrate 11K is adjusted by the first adjustment roller 607, an excess portion protruding from the feed roller 602 and the driven roller 603 is generated in the positive electrode sheet substrate 11K.

[0069] The controller 601 operates the cutter 609 to cut off the excess portion of the positive electrode sheet substrate 11K together with the cutter support 610. The controller 601 controls the starting position of the winding of the positive electrode sheet substrate 11K relative to the charge / discharge body 10, using the positive electrode current collector tab 11b, which corresponds to the starting position of the winding, as a guide.

[0070] The controller 601 activates the second camera 611 to photograph the negative electrode sheet substrate 12K. Based on the image of the negative electrode sheet substrate 12K that has been photographed, the controller 601 determines whether the position of the negative electrode current collector tab 12b formed on the negative electrode sheet substrate 12K is at the position corresponding to the starting position of winding the negative electrode sheet 12 in the charge / discharge body 10. If the controller 601 determines that the position of the negative electrode current collector tab 12b is not at the corresponding position, it determines that the position of the negative electrode current collector tab 12b at the starting position of winding the negative electrode sheet substrate 12K is misaligned and adjusts the position of the negative electrode current collector tab 12b.

[0071] The controller 601 operates the second adjustment roller 612 to move the negative electrode sheet substrate 12K, which is sandwiched between the second adjustment roller 612 and the second driven roller 613, toward the cutter 609 and the cutter support 610. After the position of the negative electrode current collector tab 12b at the start of winding of the negative electrode sheet substrate 12K is adjusted by the second adjustment roller 612, an excess portion of the negative electrode sheet substrate 12K protrudes from the feed roller 602 and the driven roller 603. The controller 601 operates the cutter 609 together with the cutter support 610 to cut the excess portion of the negative electrode sheet substrate 12K. Under the control of the controller 601 as described above, the starting position of winding of the negative electrode sheet substrate 12K relative to the charge / discharge body 10 is adjusted using the negative electrode current collector tab 12b corresponding to the starting position of winding as a guide.

[0072] The controller 601 operates the feed roller 602 to feed the stacked positive electrode sheet substrate 11K, separator substrate 13K, negative electrode sheet substrate 12K, and 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, separator substrate 13K, negative electrode sheet substrate 12K, and separator substrate 13K toward the winding spindle 614.

[0073] 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 to form one charge / discharge body 10. The controller 601 operates the cutter 609 to cut 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.

[0074] Subsequently, the charge / discharge unit 10 is removed from the winding spindle 614. The charge / discharge unit 10 is placed in the container 51. The lid 52 is attached to the container 51. The electrolyte 14 is injected into the container 51 through the injection hole 52c of the lid 52. The electrolyte 14 impregnates the separator 13. The sealing plug 53 is attached to the injection hole 52c of the lid 52.

[0075] According to the embodiments described above, the following battery can be realized. The first battery is a battery comprising an electrode body (charge / discharge body 10) in which a positive electrode sheet 11 and a negative electrode sheet 12 are laminated, wherein the positive electrode sheet comprises a positive electrode current collector layer 11S having a positive electrode current collector foil body 11a and a positive electrode current collector tab 11b protruding from the widthwise edge 11c of the positive electrode current collector foil body, a positive electrode active material layer 11T laminated on the positive electrode current collector foil body excluding the widthwise edge region 720 of the positive electrode current collector foil body, and a heat-resistant layer 11Q laminated on the edge region, the base region 710 of the positive electrode current collector tab and the positive electrode active material layer. According to the first battery, it is possible to provide a battery in which there is no risk of deformation occurring in the electrode current collector tab of the positive electrode sheet.

[0076] The second battery is characterized in that, in the first battery, the heat-resistant layer is laminated on the edge region and the base region of the positive electrode current collector tab, and the third battery is characterized in that, in the first battery, an insulating layer is filled in the edge region and the base region of the positive electrode current collector tab, and the heat-resistant layer is laminated on the insulating layer.

[0077] The fourth battery is characterized in that, in any of the first to third batteries, the negative electrode sheet has a negative electrode current collector layer 12S having a negative electrode current collector foil body 12a and a negative electrode current collector tab 12b protruding from the widthwise edge 12c of the negative electrode current collector foil body in the same direction as or opposite to the positive electrode current collector tab, and a negative electrode active material layer 12T laminated up to the edge of the negative electrode current collector foil body, wherein the edge 12c of the negative electrode current 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 position of the electrode edge where metal burrs are likely to form (edge ​​12c of the negative electrode current collector foil body 12a) is located inward in the widthwise direction of the sheet from the edge 11c of the positive electrode current collector foil body 11a, thereby suppressing short circuits.

[0078] The fifth battery is characterized in that, in any of the first to fourth batteries, the positive electrode sheet and the negative electrode sheet are laminated with a separator 13 in between, and the widthwise edge 13a of the separator is located outside the widthwise edge 11c of the positive electrode current collector foil body. The fifth battery prevents short circuits.

[0079] The sixth battery is characterized in that, in any of the first to fifth batteries, it comprises an external terminal 40 and a current collector 20 connected to the external terminal, and the positive electrode current collector tab has a joint portion 760 joined to the current collector and a rounded portion 740 that extends from the joint portion to the edge of the positive electrode current collector foil body, and the base region is within twice the distance from the edge of the positive electrode current collector foil body to the end of the protruding portion of the rounded portion of the positive electrode current collector tab. According to the sixth battery, a sufficient area of ​​the positive electrode current collector tab 11b is exposed from the heat-resistant layer 11Q, thereby avoiding welding defects between the positive electrode current collector tab 11b and the current collector 20.

[0080] Furthermore, the manufacturing method for a battery equipped with electrodes involves creating the electrode body by winding and stacking the positive electrode sheet 11 of the first to sixth batteries, the negative electrode sheet 12, and the separator 13. This manufacturing method makes it possible to manufacture a battery in which there is no risk of deformation occurring in the electrode current collecting tab of the positive electrode sheet.

[0081] The battery of the present invention is not limited to the configuration described in the embodiments, but can be appropriately configured based on the content described in the claims.

[0082] The battery of the present invention is not limited to lithium-ion batteries. The battery of the present invention can be applied to, for example, nickel-metal hydride batteries and lead-acid batteries. 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 configuration in which the charge / discharge unit is sealed by a container and a lid. The battery of the present invention can be applied to a configuration in which the charge / discharge unit is sealed by a laminate film. Each embodiment is described in detail or in a simplified manner to illustrate the present invention, and it is not necessary to have all the configurations described, or it may have configurations that are not shown. Also, some of the configurations of one embodiment may be deleted, replaced with the configurations of other embodiments, or combined with the configurations of other embodiments. [Explanation of symbols]

[0083] 1: Battery, 10: Charge / discharge unit (battery body), 11: Positive electrode sheet, 11Q: Heat-resistant layer, 11R: Insulating layer, 11S: Positive electrode current collector layer, 11T: Positive electrode active material layer, 11Ta: Edge of positive electrode active material layer, 11a: Positive electrode current collector foil body, 11b: Positive electrode current collector tab, 11c: Edge of positive electrode current collector foil body, 12: Negative electrode sheet, 12S: Negative electrode current collector layer, 12T: Negative electrode active material layer, 12Ta: Edge of negative electrode active material layer, 12a: Negative electrode current collector foil body, 12b: Negative electrode current collector tab, 12c: Edge of negative electrode current collector foil body, 13: Separator, 13a: Edge of separator, 14: Electrolyte, 20: Current collector, 740: Rounded part, 760: Joint part

Claims

1. A battery comprising an electrode body in which a positive electrode sheet and a negative electrode sheet are stacked, The aforementioned positive electrode sheet is A positive electrode current collector layer having a positive electrode current collector foil body and a positive electrode current collector tab protruding from the widthwise edge of the positive electrode current collector foil body, A positive electrode active material layer laminated on the positive electrode current collector foil body, excluding the edge region in the width direction of the positive electrode current collector foil body, An insulating layer is laminated in the edge region and the base region of the positive electrode current collector tab, and a heat-resistant layer is laminated on the insulating layer. battery.

2. A battery comprising an electrode body in which a positive electrode sheet and a negative electrode sheet are stacked, The aforementioned positive electrode sheet is A positive electrode current collector layer having a positive electrode current collector foil body and a positive electrode current collector tab protruding from the widthwise edge of the positive electrode current collector foil body, A positive electrode active material layer laminated on the positive electrode current collector foil body, excluding the edge region in the width direction of the positive electrode current collector foil body, Equipped with, A heat-resistant layer is laminated on the edge region and the base region of the positive electrode current collector tab. The aforementioned negative electrode sheet is A negative electrode current collector layer having a negative electrode current collector foil body and a negative electrode current collector tab protruding from the widthwise edge of the negative electrode current collector foil body in the same direction as or opposite to the positive electrode current collector tab, The negative electrode current collector foil body has a negative electrode active material layer laminated up to the edge, The edges of the negative electrode current collector foil body and the negative electrode active material layer are located within the range of the edge region. battery.

3. A battery comprising an electrode body in which a positive electrode sheet and a negative electrode sheet are stacked, The aforementioned positive electrode sheet is A positive electrode current collector layer having a positive electrode current collector foil body and a positive electrode current collector tab protruding from the widthwise edge of the positive electrode current collector foil body, A positive electrode active material layer laminated on the positive electrode current collector foil body, excluding the edge region in the width direction of the positive electrode current collector foil body, Equipped with, A heat-resistant layer is laminated on the edge region and the base region of the positive electrode current collector tab. The positive electrode sheet and the negative electrode sheet are laminated with a separator in between. The widthwise edge of the separator is located outside the widthwise edge region of the positive electrode current collector foil body. battery.

4. A battery comprising an electrode body in which a positive electrode sheet and a negative electrode sheet are stacked, The aforementioned positive electrode sheet is A positive electrode current collector layer having a positive electrode current collector foil body and a positive electrode current collector tab protruding from the widthwise edge of the positive electrode current collector foil body, A positive electrode active material layer laminated on the positive electrode current collector foil body, excluding the edge region in the width direction of the positive electrode current collector foil body, Equipped with, A heat-resistant layer is laminated on the edge region and the base region of the positive electrode current collector tab. The aforementioned battery comprises an external terminal and a current collector connected to the external terminal, The positive electrode current collector tab has a joint portion that is joined to the current collector, and a rounded portion that extends from the joint portion to the edge of the positive electrode current collector foil body, The base region is within twice the distance from the edge of the positive electrode current collector foil body to the end of the protruding positive electrode current collector tab of the rounded portion. battery.

5. An insulating layer is laminated in the edge region and the base region of the positive electrode current collector tab, and the heat-resistant layer is laminated on the insulating layer. The battery according to any one of claims 2-4.

6. The heat-resistant layer is laminated on the positive electrode active material layer. The battery according to any one of claims 1 to 4.

7. A method for manufacturing a battery equipped with an electrode body, The electrode body is created by winding and laminating a positive electrode sheet and a negative electrode sheet according to any one of claims 1 to 4 with a separator in between. Battery manufacturing method.

Images