JP7402204B2 - Battery and method for manufacturing the battery - Google Patents

Description

The present invention relates to a battery and a method for manufacturing the battery.

Batteries such as lithium ion secondary batteries generally include an electrode body having an electrode, an exterior body having an opening and accommodating the electrode body, a sealing plate that seals the opening of the exterior body, and an inside of the exterior body. A terminal is electrically connected to the electrode and extends from the sealing plate to the outside of the exterior body. BACKGROUND ART It is known that this type of battery typically has a structure in which an electrode is provided with an electrode tab group including a plurality of tabs for current collection, and the electrode is connected to a terminal via the electrode tab group. For example, Patent Document 1 listed below discloses a battery in which a positive electrode tab group is provided at one longitudinal end of an electrode body, and a negative electrode tab group is provided at the other end. A technique is disclosed in which such a group of electrode tabs is connected to an electrode current collector in a bent state.

JP 2017-50069 Publication

By the way, when a battery is used, vibrations, shocks, etc. may be applied to the battery from the outside. The tab is, for example, a part of the current collector, and is soft and susceptible to external forces. Therefore, if an external force (typically an external force applied in the longitudinal direction of the electrode body) causes the electrode body to shift from its predetermined placement position and a load is applied to the electrode tab group, the electrode tab group (positive electrode tab group and/or negative electrode tab group) may be damaged. As a result, the electrical connection between the electrode and the terminal may become unstable or a connection failure may occur, which is not preferable. In addition, according to the studies conducted by the present inventors, it was found that when the electrode tab group is connected to the electrode current collector in a bent state, the electrode tab group is easily damaged due to external force concentrated on the bent portion. .

The present invention has been made in view of the above circumstances, and its main purpose is to provide a battery in which damage to the electrode tab group is suitably prevented.

The present invention provides a battery that includes one or more electrode bodies including a positive electrode and a negative electrode, and a battery case that houses the electrode bodies. The battery case includes a bottom wall, a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall. , and a sealing plate that seals the opening. A positive electrode terminal and a negative electrode terminal are attached to the sealing plate, and the electrode body has a first end that exists in a plane direction along the first side wall, and a plurality of a negative electrode including a positive electrode tab group including a positive electrode tab; a second end portion different from the first end portion existing in a plane direction along the first side wall; and a plurality of negative electrode tabs protruding from the second end portion. It has a group of tabs. The positive electrode tab group and the positive electrode terminal are electrically connected through a positive electrode current collector, and the positive electrode tabs constituting the positive electrode tab group have tips of the positive electrode tabs along the second side wall. The negative electrode tab group and the negative terminal are connected to each other through the negative electrode current collector. The negative electrode tabs that are electrically connected and constitute the negative electrode tab group include a negative electrode tab curved portion that is curved such that the tip portion of the negative electrode tab is disposed along the second side wall, and the negative electrode current collector. a negative electrode tab joint portion joined to the negative electrode tab joint portion. Here, the positive electrode tab curved portion of at least some of the positive electrode tabs forming the positive electrode tab group and/or the negative electrode tab curved portion of at least some of the negative electrode tabs forming the negative electrode tab group are provided with a reinforcing portion. is equipped.

As described above, by providing the positive electrode tab and/or the negative electrode tab with the reinforcing portion, the strength of the electrode tab group can be suitably improved. Thereby, damage to the electrode tab group that may occur when the electrode body moves within the battery case (typically, movement in the longitudinal direction of the electrode body) can be suitably prevented.

In one aspect of the battery disclosed herein, the plurality of positive electrode tabs are joined to the positive electrode current collector in a state where they are gathered on one of the first sidewalls of the pair of first sidewalls, The plurality of negative electrode tabs are joined to the negative electrode current collector in a state where they are gathered on one side of the first sidewall of the pair of first sidewalls.

In a preferred embodiment of the battery disclosed herein, the reinforcing portion is provided in the positive electrode tabs of 1/5 or less of the positive electrode tabs counted from the one with the gentlest curvature among all the positive electrode tabs constituting the positive electrode tab group. The curved portion and/or the negative tab curved portion is provided in ⅕ or less of the negative tabs counted from the one with the gentlest curvature among all the negative tabs constituting the negative tab group. According to this configuration, even when the positive electrode tab and/or the negative electrode tab is provided with a reinforcing portion, it is possible to suppress an excessive increase in the volume of the positive electrode tab group and/or the negative electrode tab group, which is preferable.

In a preferred embodiment of the battery disclosed herein, the reinforcing portion extends from the first end of the positive electrode tab, where the shortest length from the first end of the positive electrode tab to the positive electrode tab joint portion is taken as 100%. The range from the part where the length is 30% to the part where the length is 70%, and/or the shortest length from the second end of the negative tab to the negative tab joint part. When it is set as 100%, the range from the part where the length is 30% to the part where the length is 70% from the second end is covered. As will be described in detail later, by providing a reinforcing portion in the above range of the positive electrode tab and/or negative electrode tab, damage to the electrode tab group can be more preferably prevented.

In one embodiment of the battery disclosed herein, the reinforcing portion includes a base material made of resin and an adhesive layer formed on the base material.

In one embodiment of the battery disclosed herein, the reinforcing portion is a resistance layer formed on the positive electrode tab curved portion and/or the negative electrode tab curved portion.

Furthermore, from another aspect, a method for manufacturing any of the batteries disclosed herein is provided. The method for manufacturing a battery includes one or more electrode bodies including a positive electrode and a negative electrode, and a battery case accommodating the electrode body, wherein the battery case has a bottom wall and a bottom wall. , an exterior body having a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall; a sealing plate for sealing the opening, a positive electrode terminal and a negative electrode terminal are attached to the sealing plate, and the electrode body has a first electrode located in a plane direction along the first side wall. an end portion, a positive electrode tab group including a plurality of positive electrode tabs protruding from the first end portion, a second end portion different from the first end portion that exists in a plane direction along the first side wall; a negative electrode tab group including a plurality of negative electrode tabs protruding from a second end, the positive electrode tab group and the positive electrode terminal are electrically connected via a positive electrode current collector, and the positive electrode The positive electrode tab constituting the tab group includes a positive electrode tab curved portion that is curved such that the tip portion of the positive electrode tab is arranged along the second side wall, and a positive electrode tab joint portion that is joined to the positive electrode current collector. , the negative electrode tab group and the negative electrode terminal are electrically connected via a negative electrode current collector, and the negative electrode tabs constituting the negative electrode tab group have the tip portions of the negative electrode tabs connected to the negative electrode terminals. This is a method of manufacturing a battery including a negative electrode tab curved portion that is curved so as to be arranged along a second side wall, and a negative electrode tab joint portion that is joined to the negative electrode current collector. In addition, the method for manufacturing the battery includes the following steps: the positive tab curved portion of at least some of the positive tabs constituting the positive tab group, and/or the positive tab curved portion of at least some of the negative tabs constituting the negative tab group. an electrode tab group forming step of forming an electrode tab group in which the negative electrode tab curved portion is provided with a reinforcing portion; and forming the tip portion of the positive electrode tab constituting the positive electrode tab group and the negative electrode tab group. The method includes a joining step of joining the positive electrode tab group and the negative electrode tab group to their corresponding current collectors so that the tip portions of the negative electrode tabs are arranged along the second side wall. According to this method of manufacturing a battery, it is possible to obtain a battery in which damage to the electrode tab group is suitably prevented.

In one aspect of the battery manufacturing method disclosed herein, in the bonding step, the plurality of positive electrode tabs are assembled on one of the first sidewalls of the pair of first sidewalls, and the positive electrode assembly is The plurality of negative electrode tabs are joined to the negative electrode current collecting portion in a state where the plurality of negative electrode tabs are gathered on one of the first sidewalls of the pair of first sidewalls.

In a preferred embodiment of the method for manufacturing a battery disclosed herein, the reinforcing portion is provided in 1/5 or less of the positive electrode tabs counted from the one with the gentlest curvature among all the positive electrode tabs constituting the positive electrode tab group. The negative electrode tab curved portion is provided in the positive electrode tab curved portion and/or the negative electrode tab curved portion of ⅕ or less of the negative electrode tabs counted from the one with the gentlest curvature among all the negative electrode tabs constituting the negative electrode tab group. According to this configuration, even when the positive electrode tab and/or the negative electrode tab is provided with a reinforcing portion, the tabs can be easily collected, which is preferable.

In a preferred embodiment of the method for manufacturing a battery disclosed herein, the reinforcing portion has the above-mentioned reinforcing portion, when the shortest length from the first end of the positive electrode tab to the positive electrode tab joint portion is taken as 100%. The range from 30% to 70% of the length calculated from the first end, and/or the shortest length from the second end to the negative tab joint of the negative tab. When the length is 100%, it covers a range from a portion where the length is 30% to a portion where the length is 70% calculated from the second end. Although details will be described later, it is preferable to provide a reinforcing portion in the above range of the positive electrode tab and/or negative electrode tab, since it is possible to obtain a battery in which damage to the electrode tab group is more appropriately prevented.

In one embodiment of the battery manufacturing method disclosed herein, the reinforcing portion includes a base material made of resin and an adhesive layer formed on the base material.

In one aspect of the battery manufacturing method disclosed herein, the reinforcing portion is a resistance layer formed on the positive electrode tab curved portion and/or the negative electrode tab curved portion.

FIG. 1 is a perspective view schematically showing a battery according to an embodiment. FIG. 2 is a schematic vertical cross-sectional view taken along line II-II in FIG. 1. FIG. FIG. 2 is a schematic vertical cross-sectional view taken along line III-III in FIG. 1. FIG. 2 is a schematic cross-sectional view taken along line IV-IV in FIG. 1. FIG. 5 is a partially enlarged view schematically showing the vicinity of a positive electrode tab group and a negative electrode tab group in FIG. 4. FIG. It is a perspective view which shows typically the electrode body group attached to the sealing board. It is a perspective view which shows typically the electrode body to which the positive electrode 2nd current collection part and the negative electrode 2nd current collection part were attached. FIG. 1 is a schematic diagram showing the configuration of a wound electrode body according to an embodiment. 5 is a partially enlarged view schematically showing the vicinity of the positive electrode tab group in FIG. 4. FIG. FIG. 10 is a schematic diagram showing a state of the positive electrode tab 22t' when the positive electrode tab group in FIG. 9 is released from the curved state. 1 is a flowchart for explaining a method for manufacturing a battery according to an embodiment. FIG. 2 is a perspective view schematically showing a sealing plate to which a positive electrode terminal, a negative electrode terminal, a first positive current collector, a first negative current collector, a positive insulating member, and a negative insulating member are attached. FIG. 13 is a perspective view of the sealing plate of FIG. 12 turned over; FIG. 3 is a schematic cross-sectional view illustrating a battery insertion process according to one embodiment. It is a typical explanatory view for explaining a reinforcement part concerning other embodiments. It is a typical explanatory view for explaining a reinforcement part concerning other embodiments.

Hereinafter, some preferred embodiments of the technology disclosed herein will be described with reference to the drawings. Further, matters other than those specifically mentioned in this specification that are necessary for carrying out the present invention (for example, the general structure and manufacturing process of a battery that do not characterize the present invention) are well known in the field. This can be understood as a matter of design by a person skilled in the art based on the prior art. The present invention can be implemented based on the content disclosed in this specification and the common general knowledge in the field. Note that the following description is not intended to limit the technology disclosed herein to the following embodiments. Further, in this specification, the notation "A to B" indicating a range includes the meanings of "A to B" as well as "preferably larger than A" and "preferably smaller than B."

Note that in this specification, the term "battery" refers to all electricity storage devices that can extract electrical energy, and is a concept that includes primary batteries and secondary batteries. In addition, in this specification, "secondary battery" is a term that refers to all electricity storage devices that can be repeatedly charged and discharged, and includes so-called storage batteries (chemical batteries) such as lithium-ion secondary batteries and nickel-metal hydride batteries, and This concept includes capacitors (physical batteries) such as double layer capacitors.

<Summary of configuration of battery 100>
FIG. 1 is a perspective view of a battery 100. FIG. 2 is a schematic vertical cross-sectional view taken along line II-II in FIG. FIG. 3 is a schematic vertical cross-sectional view taken along line III--III in FIG. FIG. 4 is a schematic cross-sectional view taken along line IV-IV in FIG. In the following description, the symbols L, R, F, Rr, U, and D in the drawings represent left, right, front, rear, top, and bottom, and the symbols X, Y, and Z in the drawings represent the battery 100. The short side direction, the long side direction perpendicular to the short side direction (also referred to as the longitudinal direction of the electrode body), and the vertical direction are respectively represented. However, these directions are merely for convenience of explanation, and do not limit the installation form of the battery 100 in any way.

As shown in FIG. 2, the battery 100 includes a battery case 10 and an electrode body 20. In addition to the battery case 10 and the electrode body 20, the battery 100 according to the present embodiment also includes a positive terminal 30, a positive external conductive member 32, a negative terminal 40, a negative external conductive member 42, and an external insulating member 92. , a positive electrode current collector 50 , a negative electrode current collector 60 , a positive electrode insulating member 70 , and a negative electrode insulating member 80 . Although not shown, the battery 100 according to this embodiment further includes an electrolyte. Battery 100 is a lithium ion secondary battery here. The battery 100 according to this embodiment is characterized by having a reinforcing portion 27, which will be described later, and the other configuration may be the same as the conventional one. Note that the reinforcing portion 27 is an example of the reinforcing portion disclosed herein.

The battery case 10 is a housing that houses the electrode body 20. The battery case 10 has a rectangular parallelepiped shape (square) that is flat and has a bottom. The material of the battery case 10 may be the same as that conventionally used and is not particularly limited. It is preferable that the battery case 10 is made of metal having a predetermined strength. Specifically, the tensile strength of the metal used for the battery case 10 is suitably about 50 N/mm ² to 200 N/mm ² . Further, the physical property value (rigidity) of the metal used for the battery case 10 is preferably about 20 GPa to 100 GPa. Examples of this type of metal material include aluminum, aluminum alloy, iron, iron alloy, and the like.

The battery case 10 includes an exterior body 12, a sealing plate 14, and a gas exhaust valve 17. The exterior body 12 is a flat rectangular container with an opening 12h on one side. Specifically, as shown in FIG. 1, the exterior body 12 includes a substantially rectangular bottom wall 12a, a pair of first side walls 12b extending upward U from the short side of the bottom wall 12a, and facing each other. A pair of second side walls 12c extending upward U from the long sides of the bottom wall 12a and facing each other are provided. The area of the second side wall 12c is smaller than the area of the first side wall 12b. The opening 12h is formed on the upper surface of the exterior body 12 surrounded by the pair of first side walls 12b and the pair of second side walls 12c. The sealing plate 14 is attached to the exterior body 12 so as to close the opening 12h of the exterior body 12. The sealing plate 14 is a substantially rectangular plate material when viewed from above. The sealing plate 14 faces the bottom wall 12a of the exterior body 12. The battery case 10 is formed by joining (for example, welding) a sealing plate 14 to the periphery of the opening 12h of the exterior body 12. The sealing plate 14 can be joined by welding such as laser welding, for example.

As shown in FIGS. 1 and 2, the gas exhaust valve 17 is formed on the sealing plate 14. The gas exhaust valve 17 is configured to open and discharge the gas within the battery case 10 when the pressure within the battery case 10 exceeds a predetermined value.

Further, the sealing plate 14 is provided with a liquid injection hole 15 and two terminal insertion holes 18 and 19. The liquid injection hole 15 communicates with the internal space of the exterior body 12 and is an opening provided for injecting an electrolytic solution in the manufacturing process of the battery 100. The liquid injection hole 15 is sealed by a sealing member 16. As such a sealing member 16, for example, a blind rivet is suitable. Thereby, the sealing member 16 can be firmly fixed inside the battery case 10.

FIG. 6 is a perspective view schematically showing the electrode body 20 attached to the sealing plate 14. In this embodiment, a plurality of (here, three) electrode bodies 20a, 20b, and 20c are housed inside the battery case 10. Note that the number of electrode bodies 20 accommodated inside one battery case 10 is not particularly limited, and may be one, or two or more (plurality). Further, as shown in FIG. 2, a positive electrode current collector 50 is disposed on one side of each electrode body 20 in the long side direction Y (left side in FIG. ) is arranged with a negative electrode current collector 60. Each of the electrode bodies 20a, 20b, and 20c is connected in parallel. However, the electrode bodies 20a, 20b, and 20c may be connected in series. The electrode body 20 is housed inside the exterior body 12 of the battery case 10 while being covered with an electrode body holder 29 (see FIG. 3) made of a resin sheet.

FIG. 7 is a perspective view schematically showing the electrode body 20a. FIG. 8 is a schematic diagram showing the configuration of the electrode body 20a. In addition, although the electrode body 20a will be explained in detail below as an example, the electrode bodies 20b and 20c can also have a similar configuration.

As shown in FIG. 8, the electrode body 20a includes a positive electrode 22, a negative electrode 24, and a separator 26. The electrode body 20a here is a wound electrode body in which a band-shaped positive electrode 22 and a band-shaped negative electrode 24 are laminated with two band-shaped separators 26 in between, and are wound around a winding axis WL. However, the structure of the electrode body does not limit the technology disclosed herein. For example, an electrode body is formed by stacking a plurality of square (typically rectangular) positive electrodes and a plurality of square (typically rectangular) negative electrodes in an insulated state. It may be a laminated electrode body.

The electrode body 20a has a flat shape. The electrode body 20a is arranged inside the exterior body 12 with the winding axis WL substantially parallel to the long side direction Y. Specifically, as shown in FIG. 3, the electrode body 20a connects a pair of curved portions (R portions) 20r facing the bottom wall 12a of the exterior body 12 and the sealing plate 14, and a pair of curved portions 20r. , and a flat portion 20f facing the second side wall 12c of the exterior body 12. The flat portion 20f extends along the second side wall 12c.

As shown in FIG. 8, the positive electrode 22 includes a positive electrode current collector 22c, and a positive electrode active material layer 22a and a positive electrode protective layer 22p fixed on at least one surface of the positive electrode current collector 22c. However, the positive electrode protective layer 22p is not essential and can be omitted in other embodiments. The positive electrode current collector 22c is strip-shaped. The positive electrode current collector 22c is made of a conductive metal such as aluminum, aluminum alloy, nickel, stainless steel, or the like. The positive electrode current collector 22c is a metal foil, specifically an aluminum foil here.

As shown in FIG. 8, the plurality of positive electrode tabs 22t protrude from the first end portion 21a existing in the long side direction Y (which can also be called the surface direction along the first side wall 12b of the electrode body 20a). . Further, the plurality of positive electrode tabs 22t are provided at intervals (intermittently) along the longitudinal direction of the strip-shaped positive electrode 22. The positive electrode tab 22t is a part of the positive electrode current collector 22c, and is made of metal foil (aluminum foil). However, the positive electrode tab 22t may be a separate member from the positive electrode current collector 22c. Although the shape of the tab is rectangular here, it can also be made into various other shapes (eg, trapezoidal). In at least a portion of the positive electrode tab 22t, a region where the positive electrode current collector 22c is exposed is formed without forming the positive electrode active material layer 22a and the positive electrode protection layer 22p.

As shown in FIG. 4, the plurality of positive electrode tabs 22t are stacked at one end in the axial direction of the winding shaft WL (the left end in FIG. 4), and constitute the positive electrode tab group 23. The plurality of positive electrode tabs 22t are gathered on the side of one of the pair of first side walls 12b, and are joined to the positive electrode second current collector 52 in a curved state. Thereby, the accommodation capacity in the battery case 10 can be improved and the battery 100 can be made smaller. As shown in FIG. 2, the positive electrode tab group 23 is electrically connected to the positive electrode terminal 30 via the positive electrode current collector 50. Specifically, the positive electrode tab group 23 and the positive electrode second current collector 52 are connected at the connecting portion 22J (see FIG. 4). The second positive current collector 52 is electrically connected to the positive terminal 30 via the first positive current collector 51 . Note that the size of the plurality of positive electrode tabs 22t (the length along the long side direction Y and the width perpendicular to the long side direction Y, see FIG. 8) is determined by considering the state in which they are connected to the positive electrode current collector 50, for example. It can be adjusted as appropriate depending on the formation position and the like. Here, the sizes of the plurality of positive electrode tabs 22t are different from each other so that the outer ends are aligned when curved.

As shown in FIGS. 4 and 5, the positive electrode tab 22t constituting the positive electrode tab group 23 has a positive electrode tab curved portion 22A that is curved so that the tip portion 22S of the positive electrode tab 22t is disposed along the second side wall 12c. , and a positive electrode tab joint 22J joined to the positive electrode current collector 50 (specifically, the positive electrode second current collector 52). The positive electrode tab curved portion 22A can also be referred to as a portion of the positive electrode tab 22t that extends from the portion protruding from the first end portion 21a to the positive electrode tab joint portion 22J. Although details will be described later, in the battery 100 according to the present embodiment, the reinforcing portion 27 is disposed on the outermost positive electrode tab 22t' of the positive electrode tabs 22t forming the positive electrode tab group 23.

As shown in FIG. 8, the positive electrode active material layer 22a is provided in a strip shape along the longitudinal direction of the strip-shaped positive electrode current collector 22c. The positive electrode active material layer 22a includes a positive electrode active material (for example, a lithium transition metal composite oxide such as a lithium nickel cobalt manganese composite oxide) that can reversibly insert and release charge carriers. When the entire solid content of the positive electrode active material layer 22a is 100% by mass, the positive electrode active material may occupy approximately 80% by mass or more, typically 90% by mass or more, for example, 95% by mass or more. The positive electrode active material layer 22a may contain arbitrary components other than the positive electrode active material, such as a conductive material, a binder, and various additive components. As the conductive material, for example, a carbon material such as acetylene black (AB) can be used. As the binder, for example, polyvinylidene fluoride (PVdF) can be used.

As shown in FIG. 8, the positive electrode protective layer 22p is provided at the boundary between the positive electrode current collector 22c and the positive electrode active material layer 22a in the long side direction Y. The positive electrode protective layer 22p is provided here at one end in the axial direction of the winding axis WL of the positive electrode current collector 22c (the left end in FIG. 8). The positive electrode protective layer 22p is provided in a strip shape along the positive electrode active material layer 22a. The positive electrode protective layer 22p contains an inorganic filler (for example, alumina or boehmite). When the entire solid content of the positive electrode protective layer 22p is 100% by mass, the inorganic filler may account for approximately 50% by mass or more, typically 70% by mass or more, for example 80% by mass or more. The positive electrode protective layer 22p may contain arbitrary components other than the inorganic filler, such as a conductive material (eg, carbon material), a binder, and various additive components. The conductive material and binder may be the same as those exemplified as being included in the positive electrode active material layer 22a.

As shown in FIG. 8, the negative electrode 24 includes a negative electrode current collector 24c and a negative electrode active material layer 24a fixed on at least one surface of the negative electrode current collector 24c. The negative electrode current collector 24c is strip-shaped. The negative electrode current collector 24c is made of a conductive metal such as copper, copper alloy, nickel, and stainless steel. The negative electrode current collector 24c is a metal foil, specifically a copper foil here.

As shown in FIG. 8, the plurality of negative electrode tabs 24t have a second end portion different from the first end portion 21a existing in the long side direction Y (which can also be called the surface direction along the first side wall 12b of the electrode body 20a). It protrudes from the end portion 21b. Further, the plurality of negative electrode tabs 24t are provided at intervals (intermittently) along the longitudinal direction of the strip-shaped negative electrode 24. The negative electrode tab 24t is a part of the negative electrode current collector 24c, and is made of metal foil (copper foil). However, the negative electrode tab 24t may be a separate member from the negative electrode current collector 24c. Although the shape of the tab is rectangular here, it can also be made into various other shapes (eg, trapezoidal). At least a portion of the negative electrode tab 24t is provided with a region where the negative electrode active material layer 24a is not formed and the negative electrode current collector 24c is exposed.

As shown in FIG. 4, the plurality of negative electrode tabs 24t are stacked at one end in the axial direction (the right end in FIG. 4) to form a negative electrode tab group 25. The negative electrode tab group 25 is preferably provided at a position symmetrical to the positive electrode tab group 23 in the axial direction. The plurality of negative electrode tabs 24t are gathered on the side of one of the pair of first side walls 12b, and are joined to the negative electrode current collector 62 in a curved state. Thereby, the accommodation capacity in the battery case 10 can be improved, and the battery 100 can be made smaller. As shown in FIG. 2, the negative electrode tab group 25 is electrically connected to the negative electrode terminal 40 via the negative electrode current collector 60. Specifically, the negative electrode tab group 25 and the negative electrode second current collector 62 are connected at the connection part J (see FIG. 4). The second negative current collector 62 is electrically connected to the negative terminal 40 via the first negative current collector 61 . Similar to the plurality of positive electrode tabs 22t, here, the plurality of negative electrode tabs 24t have different sizes so that their outer ends are aligned when curved.

As shown in FIGS. 4 and 5, the negative electrode tab 24t constituting the negative electrode tab group 25 has a negative electrode tab curved portion 24A that is curved so that the tip portion 24S of the negative electrode tab 24t is disposed along the second side wall 12c. , and a negative electrode tab joint 24J joined to the negative electrode current collector 60 (specifically, the negative electrode second current collector 62). The negative electrode tab curved portion 24A can also be referred to as a portion of the negative electrode tab 24t extending from the portion protruding from the second end portion 21b to the negative electrode tab joint portion 24J.

As shown in FIG. 8, the negative electrode active material layer 24a is provided in a strip shape along the longitudinal direction of the strip-shaped negative electrode current collector 24c. The negative electrode active material layer 24a includes a negative electrode active material (for example, a carbon material such as graphite) that can reversibly occlude and release charge carriers. When the entire solid content of the negative electrode active material layer 24a is 100% by mass, the negative electrode active material may account for approximately 80% by mass or more, typically 90% by mass or more, for example, 95% by mass or more. The negative electrode active material layer 24a may contain arbitrary components other than the negative electrode active material, such as a binder, a dispersant, various additive components, and the like. As the binder, for example, rubber such as styrene butadiene rubber (SBR) can be used. As a dispersant, for example, cellulose such as carboxymethyl cellulose (CMC) can be used.

The separator 26 is a member that insulates the positive electrode active material layer 22a of the positive electrode 22 and the negative electrode active material layer 24a of the negative electrode 24, as shown in FIG. As the separator 26, a porous sheet made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP) is suitable, for example. The separator 26 has a base material portion made of a porous sheet made of resin, and a heat resistance layer (HRL) provided on at least one surface of the base material portion and containing an inorganic filler. Good too. As the inorganic filler, for example, alumina, boehmite, aluminum hydroxide, titania, etc. can be used.

The electrolyte may be the same as the conventional one and is not particularly limited. The electrolytic solution is, for example, a non-aqueous electrolytic solution containing a non-aqueous solvent and a supporting salt. The non-aqueous solvent includes carbonates such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. The supporting salt is, for example, a fluorine-containing lithium salt such as _LiPF6 . However, the electrolytic solution may be in a solid state (solid electrolyte) and may be integrated with the electrode body 20.

As shown in FIG. 2, the positive electrode terminal 30 is inserted into a terminal insertion hole 18 formed at one end (left end in FIG. 2) of the sealing plate 14 in the long side direction Y. The positive electrode terminal 30 is preferably made of metal, and more preferably made of aluminum or an aluminum alloy, for example. On the other hand, the negative electrode terminal 40 is inserted into a terminal insertion hole 19 formed at the other end of the sealing plate 14 in the long side direction Y (the right end in FIG. 2). Note that the negative electrode terminal 40 is preferably made of metal, and more preferably made of copper or a copper alloy, for example. These electrode terminals (positive electrode terminal 30, negative electrode terminal 40) each protrude from the same surface of battery case 10 (specifically, sealing plate 14). However, the positive electrode terminal 30 and the negative electrode terminal 40 may each protrude from different surfaces of the battery case 10. Moreover, it is preferable that the electrode terminals (positive electrode terminal 30, negative electrode terminal 40) inserted into the terminal insertion holes 18 and 19 be fixed to the sealing plate 14 by caulking or the like.

As described above, as shown in FIG. It is electrically connected to the positive electrode 22 (for details, the positive electrode tab group 23, see FIG. 8) of the electrode body. The positive electrode terminal 30 is insulated from the sealing plate 14 by the positive electrode insulating member 70 and the gasket 90. Note that the positive electrode insulating member 70 includes a base portion 70a interposed between the positive electrode first current collecting portion 51 and the sealing plate 14, and a protruding portion 70b protruding from the base portion 70a toward the electrode body 20 side. . The positive electrode terminal 30 exposed to the outside of the battery case 10 through the terminal insertion hole 18 is connected to the positive external conductive member 32 outside the sealing plate 14 . On the other hand, as shown in FIG. 2, the negative electrode terminal 40 is connected to each electrode body through the negative electrode current collector 60 (negative electrode first current collector 61, negative electrode second current collector 62) inside the exterior body 12. It is electrically connected to the negative electrode 24 of No. 20 (for details, refer to the negative electrode tab group 25, FIG. 8). Negative electrode terminal 40 is insulated from sealing plate 14 by negative electrode insulating member 80 and gasket 90. Note that, similarly to the positive electrode insulating member 70, the negative electrode insulating member 80 also includes a base portion 80a interposed between the negative electrode first current collector 61 and the sealing plate 14, and a base portion 80a that protrudes toward the electrode body 20 side from the base portion 80a. A protrusion 80b is provided. The negative electrode terminal 40 exposed to the outside of the battery case 10 through the terminal insertion hole 19 is connected to the negative external conductive member 42 outside the sealing plate 14 . An external insulating member 92 is interposed between the above-mentioned external conductive members (positive external conductive member 32, negative external conductive member 42) and the outer surface 14d of the sealing plate 14. The external insulating member 92 can insulate the external conductive members 32 and 42 from the sealing plate 14.

Further, the protrusions 70b and 80b of the above-mentioned insulating members (positive electrode insulating member 70, negative electrode insulating member 80) are arranged between the sealing plate 14 and the electrode body 20. The upward movement of the electrode body 20 is restricted by the protrusions 70b and 80b of the insulating member, and contact between the sealing plate 14 and the electrode body 20 can be prevented.

Next, the reinforcing portion 27 included in the battery 100 according to the present embodiment will be described in detail. As shown in FIGS. 6 and 9, in the battery 100 according to the present embodiment, the positive tab curved portion 22A' of the outermost positive tab 22t' of the positive tabs 22t constituting the positive tab group 23 is reinforced. 27 is arranged. In this way, by providing the positive electrode tab 22t (here, the positive electrode tab 22t') with the reinforcing portion 27, the strength of the positive electrode tab group 23 can be suitably improved. As a result, damage to the positive electrode tab group 23 that may occur when the electrode body 20a moves within the battery case 10 (typically, movement in the longitudinal direction of the electrode body 20a) can be suitably prevented. can.

In addition, the number of positive electrode tabs (hereinafter also simply referred to as "the number of positive electrode tabs") whose positive electrode tab curved portions are provided with reinforcing parts among all the positive electrode tabs constituting the positive electrode tab group depends on the technology disclosed herein. For example, the entire positive electrode tab constituting the positive electrode tab group may be provided with a reinforcing portion. Further, from the viewpoint of suppressing an excessive increase in the volume of the positive electrode tab group, the number of positive electrode tabs is preferably 1/2 or less, counting from the one with the gentler curvature (here, the positive electrode tab 22t'). More preferably, the number is 1/3 or less, for example, 1/4 or less, and even more preferably 1/5 or less (that is, corresponding to this embodiment). Further, the number of the positive electrode tabs may be at least one or more.

FIG. 10 is a schematic diagram showing the state of the positive electrode tab 22t' when the positive electrode tab group 23 shown in FIG. 9 is released from the curved state. Here, the covering range of the reinforcing part 27 in the positive electrode tab curved part 22A is not particularly limited as long as the effect of the technology disclosed herein is exhibited, but for example, from the first end 21a of the positive electrode tab 22t' to the positive electrode When the shortest length to the tab joint part 22J' (i.e., the length of the positive electrode tab curved part 22A') is taken as 100%, 60% from the part where the length starting from the first end 21a is 40%. It is preferable that the range up to the part is covered, and the range from the part where the length calculated from the first end 21a is 30% to the part where it is 70% is covered. The case is more preferable. This configuration is preferable because a particularly large curved portion of the positive tab curved portion 22A' of the positive tab 22t' can be reliably reinforced.

The reinforcing part 27 is not particularly limited as long as the effects of the technology disclosed herein are exhibited, but for example, one comprising a base material and an adhesive layer formed on the base material is preferably used. be able to. The above base material is composed of resins such as polyethylene (PE), polypropylene (PP), polyester, nylon, vinyl chloride, Teflon (registered trademark), polyimide, Kapton (registered trademark), polyphenylene sulfide, and polyethylene naphthalate. can be preferably used. The thickness of the base material is not particularly limited as long as the effects of the technology disclosed herein are exhibited, but it can be approximately 5 μm to 100 μm, preferably 10 μm to 50 μm. Furthermore, examples of materials constituting the adhesive layer include acrylic adhesives, silicone adhesives, rubber adhesives, and the like. It is preferable that the adhesive layer has adhesiveness at room temperature (typically, about 20° C.). The thickness of the adhesive layer is not particularly limited as long as the effects of the technology disclosed herein are exhibited, but it can be approximately 5 μm to 100 μm, preferably 5 μm to 20 μm. Note that the reinforcing portion 27 may be configured by combining a plurality of reinforcing portions and a plurality of types of reinforcing portions.

<Method for manufacturing battery 100>
The method for manufacturing the battery 100 is characterized by the use of the reinforcing portion 27 as described above. Other manufacturing processes may be the same as conventional ones. In addition to the reinforcing portion 27, the battery 100 includes the above-described battery case 10 (exterior body 12 and sealing plate 14), electrode body group 20 (electrode bodies 20a, 20b, 20c), an electrolyte, and a positive terminal. 30, negative electrode terminal 40, positive electrode current collector 50 (positive electrode first current collector 51 and positive electrode second current collector 52), negative electrode current collector 60 (negative electrode first current collector 61 and negative electrode second collector) The electrical part 62) can be prepared, and manufactured by a manufacturing method including, for example, a mounting process, an insertion process, and a sealing process. Furthermore, the method for manufacturing the battery 100 according to the present embodiment is characterized by including step S1 (electrode tab group forming step) and step S2 (joining step) as shown in the flowchart of FIG. Note that although a method for manufacturing the battery 100 will be described below, it is not intended to limit the method for manufacturing the battery disclosed herein. Further, the manufacturing method disclosed herein may change the order of the steps as appropriate, or may further include other steps at any stage.

In the attachment process, a first combined object as shown in FIGS. 12 and 13 is produced. Specifically, first, the sealing plate 14 is provided with the positive electrode terminal 30, the positive electrode first current collector 51, the positive electrode insulating member 70, the negative electrode terminal 40, the negative electrode first current collector 61, and the negative electrode insulating member 80. , install.

The positive electrode terminal 30, the positive electrode first current collector 51, and the positive electrode insulating member 70 are fixed to the sealing plate 14 by caulking (riveting), for example. The caulking process is performed by sandwiching the gasket 90 between the outer surface of the sealing plate 14 and the positive electrode terminal 30, and further sandwiching the positive electrode insulating member 70 between the inner surface of the sealing plate 14 and the positive electrode first current collector 51. It will be held in Note that the material of the gasket 90 may be the same as that of the positive electrode insulating member 70. Specifically, the positive electrode terminal 30 before caulking is inserted from above the sealing plate 14 into the through hole 90h of the gasket 90, the terminal extraction hole 18 of the sealing plate 14, the through hole 70h of the positive electrode insulating member 70, and the first positive electrode terminal. They are inserted into the through holes 51h of the current collector 51 in order, and are made to protrude below the sealing plate 14. Then, the portion of the positive electrode terminal 30 that protrudes below the sealing plate 14 is caulked so that a compressive force is applied in the vertical direction Z. As a result, a caulked portion 30c is formed at the tip of the positive electrode terminal 30 (lower end in FIG. 2).

By such caulking, the gasket 90, the sealing plate 14, the positive electrode insulating member 70, and the positive electrode first current collector 51 are integrally fixed to the sealing plate 14, and the terminal extraction hole 18 is sealed. Note that the caulked portion 30c may be welded to the positive electrode first current collector portion 51. Thereby, conduction reliability can be further improved.

The negative electrode terminal 40, the negative electrode first current collector 61, and the negative electrode insulating member 80 can be fixed in the same manner as on the positive electrode side described above. That is, the negative electrode terminal 40 before caulking is inserted from above the sealing plate 14 into the through hole of the gasket, the terminal extraction hole 19 of the sealing plate 14, the through hole of the negative electrode insulating member 80, and the negative electrode first current collector 61. through holes 61h, and are made to protrude below the sealing plate 14. Then, the portion of the negative electrode terminal 40 that protrudes below the sealing plate 14 is caulked so that a compressive force is applied in the vertical direction Z. As a result, a caulked portion 40c is formed at the tip of the negative electrode terminal 40 (lower end in FIG. 2).

Next, the positive external conductive member 32 and the negative external conductive member 42 are attached to the outer surface of the sealing plate 14 via the external insulating member 92 . Note that the material of the external insulating member 92 may be the same as that of the positive electrode insulating member 70. Further, the timing for attaching the positive external conductive member 32 and the negative external conductive member 42 may be after the insertion process (for example, after the liquid injection hole 15 is sealed).

Subsequently, in step S1 (electrode tab group forming step), the positive electrode tab curved portion 22A (here, the positive electrode tab curved portion In the portion 22A'), an electrode tab group in which the reinforcing portion 27 is arranged is formed. Specifically, first, a strip-shaped positive electrode 22 and a strip-shaped negative electrode 24 are laminated with two strip-shaped separators 26 in between, and a wound electrode body (electrode body 20a) is wound around the winding axis WL. ) (see Figure 8). Then, a reinforcing portion is placed at a predetermined position (see FIG. 10) of the positive tab curved portion 22A′ of the outermost positive electrode tab 22t′ of the positive electrode tab 22t constituting the positive electrode tab 23 provided in the electrode body 20a. Place 27. The same applies to the other electrode bodies 20b and 20c. Note that the reinforcing portion 27 may be placed on the positive electrode tab curved portion 22A′ before the strip-shaped positive electrodes 22 are stacked, or when the first positive current collecting portion 51 and the second positive current collecting portion 52 are arranged. It may be done before joining.

Next, in step S2 (joining step), a second combined product as shown in FIG. 6 is produced. That is, the electrode body group 20 integrated with the sealing plate 14 is produced. Specifically, as shown in FIG. 7, first, the positive electrode tab group 23 and the negative electrode tab group 25 in the electrode body 20a are connected to the corresponding current collecting parts (i.e., the positive electrode second current collecting part 52 and the negative electrode second collecting part 52). 62). Three such electrode bodies 20a are prepared and arranged side by side in the short side direction X as electrode bodies 20a, 20b, and 20c. At this time, in each of the electrode bodies 20a, 20b, and 20c, the positive electrode second current collecting section 52 is arranged on one side in the long side direction Y (the left side in FIG. 6), and the negative electrode second current collecting section 62 is arranged on the long side. They may be arranged in parallel so that they are arranged on the other side in direction Y (the right side in FIG. 6).

Subsequently, as shown in FIG. 4, the plurality of positive electrode tabs 22t are gathered on one of the pair of first side walls 12b, and in a curved state (more specifically, the positive electrode tabs 22t in each electrode body are (in a curved state such that the tip portion 22S of the positive electrode tab 22t constituting the tab group 23 is arranged along the second side wall 12c), the positive electrode first current collector 51 fixed to the sealing plate 14 and , and the positive electrode second current collector portion 52 of the electrode bodies 20a, 20b, and 20c, respectively. In addition, the plurality of negative electrode tabs 24t are collected on one of the pair of first side walls 12b and in a curved state (more specifically, the negative electrode tabs 24t constituting the negative electrode tab group 25 in each electrode body The negative electrode first current collector 61 fixed to the sealing plate 14, the electrode bodies 20a, 20b, 20c and the negative electrode second current collector 62 are respectively joined. As a joining method, for example, welding such as ultrasonic welding, resistance welding, laser welding, etc. can be used. In particular, it is preferable to use welding by irradiation with high-energy radiation such as a laser.

In the insertion step, the second combined object produced in the second attachment step is accommodated in the internal space of the exterior body 12. FIG. 14 is a schematic cross-sectional view illustrating the insertion process. Specifically, first, the electrode body holder 29 is prepared by folding an insulating resin sheet made of a resin material such as polyethylene (PE) into a bag shape or a box shape. Next, the electrode body group 20 is housed in the electrode body holder 29 . Then, the electrode body group 20 covered with the electrode body holder 29 is inserted into the exterior body 12. When the weight of the electrode assembly 20 is heavy, approximately 1 kg or more, for example 1.5 kg or more, or even 2 to 3 kg, the long side wall 12b of the exterior body 12 intersects with the direction of gravity, as shown in FIG. It is preferable to insert the electrode assembly 20 into the exterior body 12 by arranging the electrode assembly 20 in the following manner (with the exterior body 12 facing sideways).

In the sealing step, the sealing plate 14 is joined to the edge of the opening 12h of the exterior body 12 to seal the opening 12h. The sealing process can be performed at the same time as the insertion process or after the insertion process. In the sealing process, it is preferable that the exterior body 12 and the sealing plate 14 are welded together. The exterior body 12 and the sealing plate 14 can be welded together by, for example, laser welding. Thereafter, the battery 100 is sealed by injecting electrolyte through the injection hole 15 and closing the injection hole 15 with the sealing member 16 . The battery 100 can be manufactured as described above.

Although the battery 100 can be used for various purposes, it is suitable for applications where external forces such as vibrations and shocks are applied during use, for example, as a power source for a motor mounted on a moving object (typically a vehicle such as a passenger car or truck). (driving power source). The type of vehicle is not particularly limited, and examples thereof include a plug-in hybrid vehicle (PHV), a hybrid vehicle (HV), an electric vehicle (EV), and the like. The battery 100 can also be suitably used as an assembled battery in which a plurality of batteries 100 are arranged in a predetermined arrangement direction and a load is applied by a restraining mechanism from the arrangement direction.

Although several embodiments of the present invention have been described above, the above embodiments are merely examples. The present invention can be implemented in various other forms. The present invention can be implemented based on the content disclosed in this specification and the common general knowledge in the field. The technology described in the claims includes various modifications and changes to the embodiments exemplified above. For example, it is also possible to replace a part of the embodiment described above with other modifications, and it is also possible to add other modifications to the embodiment described above. Also, if the technical feature is not described as essential, it can be deleted as appropriate.

For example, in the above embodiment, the reinforcing portion 27 is provided on one side of the positive tab curved portion 22A' of the positive tab 22t', but the reinforcement portion 27 is not limited thereto. The reinforcing portions may be provided on both sides of the positive electrode tab curved portion. Further, in the above embodiment, the reinforcing portion 27 covers the range from the first end 21a to a predetermined portion, but the present invention is not limited to this, and the reinforcing portion 27 may cover the entire positive electrode tab curved portion. good. Further, the reinforcing portion does not need to be provided from the end (specifically, the first end), but only in a part of the curved portion of the electrode tab (for example, from the first end 21a). Only the range from 30% to 70% of the length) may be covered. In the above embodiment, the reinforcing part 27 covers the entire range in the vertical direction Z of the positive electrode tab curved part 22A', but is not limited to this, and may cover a part of the range in the vertical direction Z. Good too.

For example, in the above embodiment, one reinforcing section 27 is used, but the present invention is not limited to this, and the reinforcing section may be configured by arranging a plurality of reinforcing sections. Further, the reinforcing portions may be arranged intermittently. In the above embodiment, the reinforcing portion 27 has a rectangular shape, but is not limited to this, and may have an elliptical shape, a square shape, or various other shapes.

For example, in the embodiment described above, the reinforcing portion is disposed only at the positive electrode tab curved portion, but the reinforcing portion is not limited thereto. The reinforcing portion may be arranged only at the negative electrode tab curved portion, or may be arranged at the positive electrode tab curved portion and the negative electrode tab curved portion. Note that the content described in the description of the reinforcing portion 27 disposed on the positive electrode tab curved portion 22A' can be applied to the reinforcing portion disposed on the negative electrode tab curved portion as appropriate.

For example, in the embodiment described above, the reinforcing portion 27 is separately arranged on the positive electrode tab curved portion 22A', but the present invention is not limited thereto. For example, as shown in FIG. 15, it is also possible to use a positive electrode tab 122t' in which a positive electrode protective layer (also referred to as a resistance layer) as a reinforcing part 127 is formed in advance on the positive electrode tab curved part 122A'. Here, the positive electrode protective layer can have the same configuration as the positive electrode protective layer 22p described above. The positive electrode protective layer may be formed on one side or both sides of the positive electrode tab curved portion 122A'. Further, the range in which the positive electrode protective layer 122p is formed can be determined by appropriately referring to the content described in the explanation of the reinforcing portion 27. Note that 120a, 122t (122t'), 122A (122A'), 122J, 123, 127, and 152 in FIG. 15 correspond to 20a, 22t (22t'), 22A (22A'), 22J, 23, and 27 and 52.

For example, in the above embodiment, the reinforcing portion 27 is provided only in the electrode tab curved portion (specifically, the positive electrode tab curved portion 22A'), but the invention is not limited to this. For example, as shown in FIG. 16, the reinforcing portion 227 may be disposed over the positive electrode tab group 223, the flat outer surface 228, and the negative electrode tab group 225. Note that 220a, 223, 225, 227, 252, and 262 in FIG. 16 correspond to 20a, 23, 25, 27, 52, and 62 in FIG. 7, respectively. Further, the reinforcing portion may be arranged from the positive electrode tab group to the flat outer surface, or may be arranged from the negative electrode tab group to the flat outer surface. In this case, the reinforcing portion can be disposed over part or the entire length of the flat outer surface in the longitudinal direction Y.

10 Battery case 12 Exterior body 14 Sealing plate 20 Electrode body group 20a, 20b, 20c, 120a, 220a Electrode body 21a First end 21b Second end 22 Positive electrode 22S Tip portion 22t, 22t', 122t, 122t' Positive electrode tab 22A, 22A', 122A, 122A' Positive electrode tab curved parts 22J, 22J', 122J Positive electrode tab joint parts 23, 223 Positive electrode tab group (electrode tab group)
24 Negative electrode 24S Tip portion 24t Negative electrode tab 24A Negative electrode tab curved portion 24J Negative electrode tab joint portion 25, 225 Negative electrode tab group (electrode tab group)
27, 127, 227 Reinforcement part 30 Positive terminal (terminal)
40 Negative terminal (terminal)
50 Positive electrode current collector 51 Positive electrode first current collector (current collector)
52, 252 Positive electrode second current collector 60 Negative electrode current collector 61 Negative electrode first current collector 62, 262 Negative electrode second current collector 70 Positive electrode insulating member (insulating member)
80 Negative electrode insulating member (insulating member)
90 Gasket 100 Battery

Claims (16)

A battery comprising one or more electrode bodies including a positive electrode and a negative electrode, and a battery case housing the electrode bodies,
The battery case is
An exterior body including a bottom wall, a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall. and,
a sealing plate that seals the opening;
It is equipped with
A positive terminal and a negative terminal are attached to the sealing plate,
The electrode body is
a positive electrode tab group including a first end portion existing in a plane direction along the first side wall, and a plurality of positive electrode tabs protruding from the first end portion;
a negative electrode tab group including a second end different from the first end existing in a plane direction along the first side wall, and a plurality of negative electrode tabs protruding from the second end;
It is equipped with
The positive electrode tab group and the positive electrode terminal are electrically connected via a positive electrode current collector,
The positive tab constituting the positive tab group includes a positive tab curved portion that is curved such that the tip of the positive tab is disposed along the second side wall, and a positive tab joint that is joined to the positive current collector. It is equipped with a section and a
The negative electrode tab group and the negative electrode terminal are electrically connected via a negative electrode current collector,
The negative electrode tabs constituting the negative electrode tab group include a negative electrode tab curved portion that is curved such that the tip portion of the negative electrode tab is disposed along the second side wall, and a negative electrode tab joint that is joined to the negative electrode current collector portion. It is equipped with a section and a
Here, the positive electrode tab curved portions of at least some of the positive electrode tabs forming the positive electrode tab group and/or the negative electrode tab curved portions of at least some of the negative electrode tabs forming the negative electrode tab group are coated with resin . A battery comprising: a reinforcing portion including a base material made of the same material, and an adhesive layer formed on the base material . one or more electrode bodies including a positive electrode and a negative electrode; a battery case housing the electrode bodies;
A battery comprising:
The battery case is
An exterior body including a bottom wall, a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall. and,
a sealing plate that seals the opening;
It is equipped with
A positive terminal and a negative terminal are attached to the sealing plate,
The electrode body is
a positive electrode tab group including a first end portion existing in a plane direction along the first side wall, and a plurality of positive electrode tabs protruding from the first end portion;
a negative electrode tab group including a second end different from the first end existing in a plane direction along the first side wall, and a plurality of negative electrode tabs protruding from the second end;
It is equipped with
The positive electrode tab group and the positive electrode terminal are electrically connected via a positive electrode current collector,
The positive electrode tabs constituting the positive electrode tab group include a positive electrode tab curved portion that is curved such that the tip portion of the positive electrode tab is arranged along the second side wall, and a positive electrode tab joint that is joined to the positive electrode current collector portion. It is equipped with a section and a
The negative electrode tab group and the negative electrode terminal are electrically connected via a negative electrode current collector,
The negative electrode tabs constituting the negative electrode tab group include a negative electrode tab curved portion that is curved such that the tip portion of the negative electrode tab is disposed along the second side wall, and a negative electrode tab joint that is joined to the negative electrode current collector portion. It is equipped with a section and a
Here, the positive electrode tab curved portion of at least some of the positive electrode tabs forming the positive electrode tab group and/or the negative electrode tab curved portion of at least some of the negative electrode tabs forming the negative electrode tab group are provided with a reinforcing portion. is equipped with
The reinforcing portion may extend only to the curved portion of the positive tab of ⅕ or less of the positive tabs counted from the one with the gentlest curvature among all the positive tabs constituting the positive tab group, and/or to the negative tab group. A battery, which is provided only in the negative tab curved portions of ⅕ or less of the negative tabs counted from the one with the gentlest curvature among all the negative electrode tabs that constitute the battery. one or more electrode bodies including a positive electrode and a negative electrode; a battery case housing the electrode bodies;
A battery comprising:
The battery case is
An exterior body including a bottom wall, a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall. and,
a sealing plate that seals the opening;
It is equipped with
A positive terminal and a negative terminal are attached to the sealing plate,
The electrode body is
a positive electrode tab group including a first end portion existing in a plane direction along the first side wall, and a plurality of positive electrode tabs protruding from the first end portion;
a negative electrode tab group including a second end different from the first end existing in a plane direction along the first side wall, and a plurality of negative electrode tabs protruding from the second end;
It is equipped with
The positive electrode tab group and the positive electrode terminal are electrically connected via a positive electrode current collector,
The positive tab constituting the positive tab group includes a positive tab curved portion that is curved such that the tip of the positive tab is disposed along the second side wall, and a positive tab joint that is joined to the positive current collector. It is equipped with a section and a
The negative electrode tab group and the negative electrode terminal are electrically connected via a negative electrode current collector,
The negative electrode tabs constituting the negative electrode tab group include a negative electrode tab curved portion that is curved such that the tip portion of the negative electrode tab is disposed along the second side wall, and a negative electrode tab joint that is joined to the negative electrode current collector portion. It is equipped with a section and a
Here, the positive electrode tab curved portion of at least some of the positive electrode tabs forming the positive electrode tab group and/or the negative electrode tab curved portion of at least some of the negative electrode tabs forming the negative electrode tab group are provided with a reinforcing portion. is equipped with
The reinforcement part is a resistance layer,
The positive electrode tab curved portion of the positive electrode tab located at the outermost surface in the curved protruding direction of the positive electrode tab curved portion in the positive electrode tab group, and/or the negative electrode tab curved portion located on the outermost surface in the curved protruding direction of the negative electrode tab curved portion in the negative electrode tab group. The reinforcing portion is formed on the negative tab curved portion of the negative tab located on the outermost surface of the battery. The plurality of positive electrode tabs are joined to the positive electrode current collector in a state where they are gathered on one first sidewall side of the pair of first sidewalls,
4. The negative electrode tabs according to claim 1, wherein the plurality of negative electrode tabs are joined to the negative electrode current collector in a state where the plurality of negative electrode tabs are gathered on one first side wall side of the pair of first side walls. Batteries listed. The reinforcing portion may extend only to the curved portion of the positive tab of ⅕ or less of the positive tabs counted from the one with the gentlest curvature among all the positive tabs constituting the positive tab group, and/or to the negative tab group. 4. The battery according to claim 3 , wherein the battery is provided only in the negative tab curved portions of ⅕ or less of the negative electrode tabs counted from the one with the gentlest curvature among all the negative electrode tabs. The reinforcing portion extends from a portion where the length starting from the first end is 30% when the shortest length from the first end of the positive tab to the positive tab joint is 100%. 70%, and/or the shortest length of the negative tab from the second end to the negative tab joint is defined as 100%, starting from the second end. The battery according to any one of claims 1 to 5 , wherein the battery covers a range from a portion where the length is 30% to a portion where the length is 70%. The battery according to claim 2 or 3 , wherein the reinforcing portion includes a base material made of resin and an adhesive layer formed on the base material. The battery according to claim 1 or 2 , wherein the reinforcing portion is a resistance layer formed on the positive electrode tab curved portion and/or the negative electrode tab curved portion. A method for manufacturing a battery comprising one or more electrode bodies including a positive electrode and a negative electrode, and a battery case housing the electrode bodies, the method comprising:
The battery case is
An exterior body including a bottom wall, a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall. and,
a sealing plate that seals the opening;
It is equipped with
A positive terminal and a negative terminal are attached to the sealing plate,
The electrode body is
a positive electrode tab group including a first end portion existing in a plane direction along the first side wall, and a plurality of positive electrode tabs protruding from the first end portion;
a negative electrode tab group including a second end different from the first end existing in a plane direction along the first side wall, and a plurality of negative electrode tabs protruding from the second end;
It is equipped with
The positive electrode tab group and the positive electrode terminal are electrically connected via a positive electrode current collector,
The positive electrode tabs constituting the positive electrode tab group include a positive electrode tab curved portion that is curved such that the tip portion of the positive electrode tab is arranged along the second side wall, and a positive electrode tab joint that is joined to the positive electrode current collector portion. It is equipped with a section and a
The negative electrode tab group and the negative electrode terminal are electrically connected via a negative electrode current collector,
The negative electrode tabs constituting the negative electrode tab group include a negative electrode tab curved portion that is curved such that the tip portion of the negative electrode tab is disposed along the second side wall, and a negative electrode tab joint that is joined to the negative electrode current collector portion. A method for manufacturing a battery comprising:
The positive tab curved portions of at least some of the positive tabs constituting the positive tab group and/or the negative tab curved portions of at least some of the negative tabs constituting the negative tab group are made of resin . an electrode tab group forming step of forming an electrode tab group including a base material and a reinforcing portion comprising an adhesive layer formed on the base material ; and
The positive electrode tab group and the negative electrode tab group are arranged so that the tip portions of the positive electrode tabs constituting the positive electrode tab group and the tip portions of the negative electrode tabs forming the negative electrode tab group are arranged along the second side wall, A joining process of joining each to the corresponding current collector;
A method of manufacturing a battery, including: one or more electrode bodies including a positive electrode and a negative electrode; a battery case housing the electrode bodies;
A method for manufacturing a battery, comprising:
The battery case is
An exterior body including a bottom wall, a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall. and,
a sealing plate that seals the opening;
It is equipped with
A positive terminal and a negative terminal are attached to the sealing plate,
The electrode body is
a positive electrode tab group including a first end portion existing in a plane direction along the first side wall, and a plurality of positive electrode tabs protruding from the first end portion;
a negative electrode tab group including a second end different from the first end existing in a plane direction along the first side wall, and a plurality of negative electrode tabs protruding from the second end;
It is equipped with
The positive electrode tab group and the positive electrode terminal are electrically connected via a positive electrode current collector,
The positive tab constituting the positive tab group includes a positive tab curved portion that is curved such that the tip of the positive tab is disposed along the second side wall, and a positive tab joint that is joined to the positive current collector. It is equipped with a section and a
The negative electrode tab group and the negative electrode terminal are electrically connected via a negative electrode current collector,
The negative electrode tabs constituting the negative electrode tab group include a negative electrode tab curved portion that is curved such that the tip portion of the negative electrode tab is disposed along the second side wall, and a negative electrode tab joint that is joined to the negative electrode current collector portion. A method for manufacturing a battery comprising:
A reinforcing portion is provided in the positive tab curved portions of at least some of the positive tabs constituting the positive tab group and/or in the negative tab curved portions of at least some of the negative tabs constituting the negative tab group. The reinforcing portion is formed only in the curved portion of the positive tab in 1/5 or less of the positive tabs counting from the one with the gentlest curvature among all the positive tabs constituting the positive tab group, and/or in the negative tab. An electrode tab group forming step of forming an electrode tab group that is provided only in the negative tab curved portion of 1/5 or less of the negative tabs counted from the one with the gentlest curvature among all the negative electrode tabs constituting the tab group. ;and,
The positive electrode tab group and the negative electrode tab group are arranged so that the tip portions of the positive electrode tabs constituting the positive electrode tab group and the tip portions of the negative electrode tabs constituting the negative electrode tab group are arranged along the second side wall, A joining process of joining each to a corresponding current collector;
A method of manufacturing a battery, including: one or more electrode bodies including a positive electrode and a negative electrode; a battery case housing the electrode bodies;
A method for manufacturing a battery, comprising:
The battery case is
An exterior body including a bottom wall, a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall. and,
a sealing plate that seals the opening;
It is equipped with
A positive terminal and a negative terminal are attached to the sealing plate,
The electrode body is
a positive electrode tab group including a first end portion existing in a plane direction along the first side wall, and a plurality of positive electrode tabs protruding from the first end portion;
a negative electrode tab group including a second end different from the first end existing in a plane direction along the first side wall, and a plurality of negative electrode tabs protruding from the second end;
It is equipped with
The positive electrode tab group and the positive electrode terminal are electrically connected via a positive electrode current collector,
The positive tab constituting the positive tab group includes a positive tab curved portion that is curved such that the tip of the positive tab is disposed along the second side wall, and a positive tab joint that is joined to the positive current collector. It is equipped with a section and a
The negative electrode tab group and the negative electrode terminal are electrically connected via a negative electrode current collector,
The negative electrode tabs constituting the negative electrode tab group include a negative electrode tab curved portion that is curved such that the tip portion of the negative electrode tab is disposed along the second side wall, and a negative electrode tab joint that is joined to the negative electrode current collector portion. A method for manufacturing a battery comprising:
A reinforcing portion is provided in the positive tab curved portions of at least some of the positive tabs constituting the positive tab group and/or in the negative tab curved portions of at least some of the negative tabs constituting the negative tab group. an electrode tab group forming step for forming an electrode tab group;
Here, the reinforcing portion is a resistance layer,
The positive electrode tab curved portion of the positive electrode tab located at the outermost surface in the curved protruding direction of the positive electrode tab curved portion in the positive electrode tab group, and/or the negative electrode tab curved portion located on the outermost surface in the curved protruding direction of the negative electrode tab curved portion in the negative electrode tab group. the reinforcing portion is formed in the negative tab curved portion of the negative tab located on the outermost surface of the negative tab;
The positive electrode tab group and the negative electrode tab group are arranged so that the tip portions of the positive electrode tabs constituting the positive electrode tab group and the tip portions of the negative electrode tabs constituting the negative electrode tab group are arranged along the second side wall, A joining process of joining each to a corresponding current collector;
A method of manufacturing a battery, including: In the joining step,
The plurality of positive electrode tabs are joined to the positive electrode current collector in a state where they are gathered on one first sidewall side of the pair of first sidewalls,
The negative electrode tabs according to any one of claims 9 to 11 are joined to the negative electrode current collector in a state where the plurality of negative electrode tabs are gathered on one of the first side walls of the pair of first side walls. How to manufacture batteries. The reinforcing portion may extend only to the curved portion of the positive tab of ⅕ or less of the positive tabs counted from the one with the gentlest curvature among all the positive tabs constituting the positive tab group, and/or to the negative tab group. The method for manufacturing a battery according to claim 9 or 11 , wherein the negative electrode tab curved portion is provided only in one-fifth or less of the negative electrode tabs counted from the one with the gentlest curvature among all the negative electrode tabs that constitute the battery. The reinforcing portion extends from a portion where the length starting from the first end is 30% when the shortest length from the first end of the positive tab to the positive tab joint is 100%. 70%, and/or the shortest length of the negative tab from the second end to the negative tab joint is defined as 100%, starting from the second end. The method for manufacturing a battery according to any one of claims 9 to 13 , wherein the battery covers a range from a portion where the length is 30% to a portion where the length is 70%. The method for manufacturing a battery according to claim 10 or 11 , wherein the reinforcing portion includes a base material made of resin and an adhesive layer formed on the base material. The method for manufacturing a battery according to claim 9 , wherein the reinforcing portion is a resistance layer formed on the positive electrode tab curved portion and/or the negative electrode tab curved portion.

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