JP2014041724A - Power storage device, and method for manufacturing electrode assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration in performance of a power storage device.SOLUTION: An insulating adhesive tape 33 is stuck to an outer periphery of an electrode assembly 12. A laminated state of a positive electrode, a negative electrode and a separator configuring the electrode assembly 12 is thereby maintained. A starting end side where the winding of the adhesive tape 33 starts and a terminal end side where the winding ends are joined on a side face 12c of the electrode assembly 12. Accordingly, a joined part 38 is disposed at a non-facing part 37 where a positive electrode active material layer of the positive electrode and a negative electrode active material layer of the negative electrode do not face each other.

Description

  The present invention relates to a power storage device in which an electrode assembly in which a positive electrode and a negative electrode are stacked is housed in a case, and a method for manufacturing an electrode assembly provided in the power storage device.

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid Vehicle) is equipped with a secondary battery such as a lithium ion battery as a power storage device that stores power supplied to an electric motor serving as a prime mover. This type of secondary battery is disclosed in Patent Document 1, for example. As shown in FIG. 20, the secondary battery 50 includes a lower case portion 52 that houses the electrode assembly 51, and an upper lid 53 that closes the opening of the lower case portion 52. The electrode assembly 51 is electrically connected to the positive electrode terminal 56 and the negative electrode terminal 57 of the upper lid 53 via the positive electrode lead portion 54 and the negative electrode lead portion 55. The electrode assembly 51 is accommodated in the lower case portion 52 with an insulating film 58 interposed between the electrode assembly 51 and the lower case portion 52. In addition, the electrode assembly 51 is laminated in layers by insulating a negative electrode obtained by applying a negative electrode active material on a metal foil and a positive electrode obtained by applying a positive electrode active material on a metal foil with a separator made of a microporous film. ing. An adhesive tape 59 for fixing the positive electrode, the negative electrode, and the separator is wound around the outer periphery of the electrode assembly 51. In the electrode assembly 51 of Patent Document 1, a plurality of adhesive tapes 59 are wound at intervals.

JP-A-6-338304

  The secondary battery 50 mentioned above becomes an assembled battery by connecting two or more in series. Each secondary battery 50 in the case of an assembled battery is fixed so as not to be separated from each other by a restraining load acting in a direction W indicated by an arrow in FIG.

  By the way, the restraining load is received by the lower case portion 52 and the electrode assembly 51 accommodated in the lower case portion 52. For this reason, as shown in FIG. 20, when the adhesive tape 59 is applied to the surface of the electrode assembly 51 that is to receive the restraining load, the adhesive tape 59 is applied to the portion where the adhesive tape 59 is applied. A surface pressure difference will occur between the parts that are not. Then, the surface pressure is higher at the portion where the adhesive tape 59 is attached, so that metal ions are deposited from the active material layer corresponding to the portion, which causes a reduction in battery performance.

  This invention was made paying attention to the problem which exists in such a prior art, and the objective is to provide the electrical storage apparatus which can suppress the fall of performance. Another object of the present invention is to provide a method for manufacturing an electrode assembly housed in the power storage device.

  In order to solve the above problems, the invention according to claim 1 is a positive electrode having a positive electrode active material layer obtained by applying a positive electrode active material to a positive electrode metal foil and a positive electrode current collecting tab protruding from one end of the positive electrode metal foil. An electrode, a negative electrode active material layer obtained by applying a negative electrode active material to a negative electrode metal foil, and a negative electrode having a negative electrode current collecting tab protruding from one end of the negative electrode metal foil, and the positive electrode and the negative electrode In a power storage device in which a case is housed in a case where an electrode assembly that forms a layer by laminating and laminating them is provided with an insulating sheet member that covers both surfaces in the stacking direction of the electrode assembly, A facing portion where a facing region in which the positive electrode active material layer and the negative electrode active material layer face each other is projected on both surfaces in the stacking direction, and a non-facing portion other than the facing portion; The connecting part that connects the sheet members is the front. It is summarized as facing the non-opposing portions.

  Even when a restraining load is applied to arrange and fix a plurality of power storage devices in parallel by disposing a connecting portion of the sheet member in the non-opposing portion, it is localized in the opposing portion of the positive electrode active material layer and the negative electrode active material layer. In particular, the increase in surface pressure is suppressed. As a result, precipitation of metal ions from the active material layer in the facing portion is suppressed. Therefore, a decrease in performance of the power storage device can be suppressed.

  According to a second aspect of the present invention, in the power storage device according to the first aspect, the non-facing portion includes a side surface of the electrode assembly orthogonal to the stacking direction of the electrode assembly, and the connecting portion The gist is that it faces the side. According to this, since the connecting portion faces the side surface of the electrode assembly, it is possible to reliably suppress a local increase in surface pressure at the facing portion between the positive electrode active material layer and the negative electrode active material layer.

  According to a third aspect of the present invention, in the power storage device according to the second aspect, the sheet member includes the positive electrode assembly among both surfaces of the electrode assembly including the entire surface of the facing portion and a side surface of the electrode assembly. The gist of the present invention is to cover both side surfaces orthogonal to the current collector side surface from which the current tab and the negative current collector tab protrude. According to this, the insulation of an electrode assembly can be ensured suitably.

  The invention according to claim 4 is the power storage device according to claim 3, wherein the sheet member is annular. According to this, the joint of a sheet member can be decreased. As a result, the assemblability of the electrode assembly can be improved.

  The invention according to claim 5 is the power storage device according to any one of claims 1 to 4, wherein the sheet member is an adhesive tape. According to this, the operation | work which covers an electrode assembly can be simplified.

  According to a sixth aspect of the present invention, in the power storage device according to any one of the first to fourth aspects, the sheet member has the positive electrode and the positive electrode on both surfaces in the stacking direction of the electrode assembly. The gist is that it is bonded with a thermosetting adhesive that cures at a temperature lower than the melting temperature of the separator that insulates the negative electrode. According to this, the operation | work which covers an electrode assembly can be simplified.

  According to a seventh aspect of the present invention, in the power storage device according to any one of the first to third aspects, the positive electrode current collecting tab and the negative electrode current collecting tab are among side surfaces of the electrode assembly. The positive electrode current collecting tab and the negative electrode current collecting tab protrude in the same direction from one current collecting side surface from which the positive electrode current collecting tab and the negative electrode current collecting tab protrude, and the sheet member includes both surfaces in the stacking direction of the electrode assembly, It has a sheet portion covering the opposite opposite surface, and the connecting portion faces both side surfaces orthogonal to the current collecting side surface of the sheet portion, and is formed in a bottomed bag shape. And According to this, the operation | work which covers an electrode assembly can be simplified.

  According to an eighth aspect of the present invention, in the power storage device according to any one of the first to third aspects, the sheet member includes a first sheet member and a second sheet member, and the first sheet The gist is that the member and the second sheet member are bonded together at the connecting portion. According to this, the electrode assembly can be covered with two insulating sheet members.

  According to a ninth aspect of the present invention, in the power storage device according to the eighth aspect, in addition to the both sides of the electrode assembly and both side surfaces orthogonal to the current collecting side surface, the sheet member includes the current collecting side. The gist is to cover the opposite surface facing the side surface. According to this, the insulation of an electrode assembly can be ensured suitably.

  The gist of a tenth aspect of the present invention is the power storage device according to the ninth aspect, wherein the sheet member does not cover the current collecting side surface. According to this, since the entire circumference of the electrode assembly is not covered with the insulating sheet member, the permeability of the electrolytic solution accommodated in the case together with the electrode assembly can be enhanced.

  The invention according to claim 11 is the power storage device according to claim 9, wherein the sheet member further covers the current collecting side surface. According to this, since the whole circumference | surroundings of an electrode assembly are covered with an insulating sheet member, the insulation of an electrode assembly and a case can be ensured more suitably.

  The invention according to claim 12 is the power storage device according to any one of claims 8 to 11, wherein the first sheet member and the second sheet member are bonded with an adhesive tape. Is the gist. According to this, the operation | work which covers an electrode assembly can be simplified.

  The invention according to claim 13 is the power storage device according to any one of claims 1 to 12, wherein the power storage device is a secondary battery. According to this, the fall of the performance of a secondary battery can be controlled.

  The invention according to claim 14 is provided between a positive electrode having a positive electrode active material layer coated with a positive electrode active material on a positive electrode metal foil and a negative electrode having a negative electrode active material layer coated with a negative electrode active material on a negative electrode metal foil. In the method of manufacturing an electrode assembly in which the electrodes are laminated with each other, the electrode assembly projects on both surfaces in the stacking direction opposing regions where the positive electrode active material layer and the negative electrode active material layer face each other when viewed from the stacking direction. And a non-opposing part other than the opposing part, and a bottom wall of the first jig having a space surrounded by a rectangular bottom wall and side walls erected from three sides of the bottom wall A sheet setting step of setting an insulating first sheet member on the inner surface of each side wall and the inner surface of each side wall; and after setting the first sheet member, a separator between the positive electrode and the negative electrode in the space of the first jig To accommodate a laminate in which these are laminated Insulating second between the laminating step and the pressing surface of the second jig for pressing the laminated body and the electrode constituting the outermost layer located on the opposite side of the first sheet member in the laminated body. A pressing step of interposing a sheet member and then pressing the laminate with the second jig; and folding the end portion of the first sheet member and the end portion of the second sheet member into the non-opposing portion The gist of the present invention is that it comprises an adhesion step for adhering to the substrate.

  According to this, since the first and second sheet members are wound around the laminate using the first and second jigs, the manufacturing process of the electrode assembly can be simplified. In addition, the first and second sheet members can be neatly wound around the electrode assembly so as not to cause displacement or wrinkles.

  According to a fifteenth aspect of the present invention, in the electrode assembly manufacturing method according to the fourteenth aspect, the non-opposing portion includes a side surface of the electrode assembly perpendicular to the stacking direction of the electrode assemblies, The gist of the invention is that the end of the first sheet member and the end of the second sheet member are folded toward the side surface and bonded to face the side surface.

  According to a sixteenth aspect of the present invention, in the method for manufacturing an electrode assembly according to the fourteenth aspect, an end portion of the first sheet member and an end portion of the second sheet member serve as electrodes constituting the outermost layer. The gist of the present invention is that the electrode assembly is folded and faced to the non-opposing part other than the opposing part on both surfaces in the stacking direction of the electrode assembly.

  According to invention of Claim 15, 16, the edge part of a 1st sheet member and the edge part of a 2nd sheet member are arrange | positioned facing the non-opposing parts other than an opposing part by folding of both ends. Can do. Therefore, the manufacturing process of the electrode assembly can be simplified.

  According to a seventeenth aspect of the present invention, in the method of manufacturing an electrode assembly according to any one of the fourteenth to sixteenth aspects, the first sheet member is adsorbed by the first jig. The second sheet member is adsorbed by the second jig. According to this, position shift of the 1st sheet member and the 2nd sheet member in the 1st jig and the 2nd jig can be controlled by adsorption.

  According to the present invention, it is possible to suppress a decrease in performance.

The disassembled perspective view of the secondary battery of 1st Embodiment. The perspective view which shows the external appearance of a secondary battery. The disassembled perspective view which shows the component of an electrode assembly. The perspective view which shows an assembled battery. The front view of an electrode assembly. (A) is the top view which looked at the electrode assembly in which the adhesive tape is not wound from the upper surface, (b) is the top view which looked at the electrode assembly in the middle of winding the adhesive tape from the upper surface, (c) FIG. 3 is a plan view of an electrode assembly wound with an adhesive tape as viewed from above. The perspective view which shows the electrode assembly of 2nd Embodiment. The top view which looked at the electrode assembly by which the insulating film was wound from the upper surface. The schematic diagram which shows the manufacture process of the electrode assembly using the 1st insulating film and the 1st jig | tool. The perspective view which shows a 2nd insulating film. The schematic diagram which shows the manufacturing process of the electrode assembly using a 2nd jig | tool. The schematic diagram which shows the press process in the manufacture process of an electrode assembly. The schematic diagram which shows the adhesion process in the manufacture process of an electrode assembly. (A), (b) is a schematic diagram which shows the electrode assembly of another example. The top view explaining the electrode assembly of another example. The front view explaining the electrode assembly of another example. The top view which shows the insulating film of another example. The perspective view explaining the electrode assembly of another example. (A), (b) is a top view explaining the insulating film used for the electrode assembly shown in FIG. The disassembled perspective view of the secondary battery in background art.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 and 2, a secondary battery 10 as a power storage device includes a case 11 in which an electrode assembly 12 is accommodated. The case 11 includes a rectangular parallelepiped main body member 13 and a rectangular flat plate-shaped lid member 14 that closes the opening 13 a of the main body member 13. Both the main body member 13 and the lid member 14 constituting the case 11 are made of metal (for example, stainless steel or aluminum). Further, the secondary battery 10 of the present embodiment is a prismatic battery whose appearance is square. Further, the secondary battery 10 of the present embodiment is a lithium ion battery.

  A positive electrode terminal 15 and a negative electrode terminal 16 for taking out electricity from the electrode assembly 12 are electrically connected to the electrode assembly 12. The positive electrode terminal 15 and the negative electrode terminal 16 are exposed to the outside of the case 11 through a pair of opening holes 14 a provided in parallel with the lid member 14 at a predetermined interval. Further, a ring-shaped insulating ring 17 a for insulating from the case 11 is attached to the positive terminal 15 and the negative terminal 16, respectively.

  As shown in FIG. 3, the electrode assembly 12 includes a sheet-like positive electrode 20 and a sheet-like negative electrode 21. The positive electrode 20 has a positive electrode metal foil (in this embodiment, an aluminum foil) 22 and a positive electrode active material layer 23 formed by applying a positive electrode active material on both surfaces thereof. The negative electrode 21 has a negative electrode metal foil (copper foil in this embodiment) 24 and a negative electrode active material layer 25 formed by applying a negative electrode active material on both surfaces thereof. The electrode assembly 12 is a layered body having a separator 26 interposed between the positive electrode 20 and the negative electrode 21. The separator 26 is made of a microporous film. For example, as shown in FIG. 6A, the electrode assembly 12 is configured by alternately laminating a plurality of positive electrodes 20 and a plurality of negative electrodes 21. That is, the electrode assembly 12 is provided with a plurality of sets each including the positive electrode 20, the negative electrode 21, and the separator 26.

  As shown in FIG. 3, a positive electrode current collecting tab 28 made of a positive electrode metal foil 22 is provided at the edge (one end) of the positive electrode 20 so as to protrude. The positive electrode current collecting tab 28 is formed in the same position and in the same shape in each positive electrode 20 constituting the electrode assembly 12. Moreover, the negative electrode current collection tab 30 which consists of the negative electrode metal foil 24 is provided in the edge part (one end) of the negative electrode 21 so that it may protrude. The negative electrode current collecting tab 30 is formed in the same shape at the same position in each negative electrode 21 constituting the electrode assembly 12. In the positive electrode 20 and the negative electrode, a region where the active material is applied becomes a coated portion, and a region where the active material is not applied becomes an uncoated portion.

  Each positive electrode 20 is laminated such that the respective positive electrode current collecting tabs 28 are arranged in a line along the lamination direction of the electrode assembly 12. Similarly, each negative electrode 21 is laminated so that the respective negative electrode current collecting tabs 30 are arranged in a row along the laminating direction of the electrode assembly 12 so as not to overlap the positive electrode current collecting tabs 28. As shown in FIG. 1, the positive electrode current collecting tabs 28 are collected in a range from one end to the other end in the stacking direction of the electrode assembly 12 to form a positive electrode current collecting group 31. The positive electrode terminal 15 is electrically joined to the positive electrode current collecting group 31. Similarly, as shown in FIG. 1, each negative electrode current collecting tab 30 is also collected in a range from one end to the other end in the stacking direction of the electrode assembly 12 to form a negative electrode current collecting group 32. The negative electrode terminal 16 is electrically connected to the negative electrode current collecting group 32.

  In the present embodiment, the electrode assembly 12 is a rectangular parallelepiped having six surfaces as shown in FIG. The six surfaces of the electrode assembly 12 are surfaces 12a and 12b that are both surfaces in the stacking direction of the electrode assembly 12, and four side surfaces 12c that are connected to the two surfaces and are orthogonal to the stacking direction of the electrode assembly 12. 12d, 12e, and 12f. The side surface 12e is a current collecting side surface from which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude. The positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude in the same direction from one side surface 12e. The side surface 12f is a bottom side surface as an opposite surface facing the side surface 12e. The side surfaces 12c and 12d are side surfaces orthogonal to the side surfaces 12e and 12f, respectively. Further, the side surfaces 12 c and 12 d are surfaces that face each other in a direction along the width direction Y orthogonal to the stacking direction of the electrode assembly 12.

  An adhesive tape 33 is wound around the outer periphery of the electrode assembly 12 as an insulating sheet for insulating the electrode assembly 12 from the metal case 11 when the electrode assembly 12 is accommodated in the main body member 13 of the case 11. The adhesive tape 33 is an insulating material and is made of, for example, polyethylene (PE), polypropylene (PP), polyphenylene sulfide (PPS), or the like. These insulating materials are also used as a material for the separator 26. Further, the adhesive tape 33 wound around the outer periphery of the electrode assembly 12 is also used as a fixing member that maintains the laminated state of the positive electrode 20, the negative electrode 21, and the separator 26. The electrode assembly 12 with the adhesive tape 33 wound around the outer periphery is inserted from the opening 13 a of the main body member 13 and accommodated in the case 11.

  As shown in FIG. 4, the secondary battery 10 configured in this way becomes an assembled battery 34 by connecting a plurality of secondary batteries 10 in series. In the case of the assembled battery 34, each secondary battery 10 is connected to the negative terminal 16 of the secondary battery 10 adjacent to the positive terminal 15, and to the positive terminal 15 of the secondary battery 10 adjacent to the negative terminal 16, respectively. Bus bar) 35 is connected. Moreover, in the assembled battery 34, the side surface of the adjacent secondary battery 10 is in contact. And each secondary battery 10 of the assembled battery 34 is fixed so that it may not mutually separate with the restraint load which acts in the direction shown by the arrow in FIG. In addition, each secondary battery 10 of the assembled battery 34 abuts the side surfaces 13b and 13c of the case 11 (main body member 13) facing each other in the stacking direction of the electrode assembly 12. For this reason, a restraining load acts on the electrode assembly 12 of each secondary battery 10 along the stacking direction. In the present embodiment, the side surfaces 13b and 13c of the case 11 are flat surfaces having no step.

  And in the secondary battery 10 of this embodiment, the structure for suppressing that constraining load concentrates on the local part of the electrode assembly 12, when using the assembled battery 34 etc. is employ | adopted. Hereinafter, the configuration of the electrode assembly 12 will be described in more detail with reference to FIGS. 5 and 6. In the following description, as shown in FIG. 5, the direction along the protruding direction of the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 is defined as the height direction X of the positive electrode 20 and the negative electrode 21, and the height direction X The orthogonal direction is defined as the width direction Y of the positive electrode 20 and the negative electrode 21.

  As shown in FIG. 5, the positive electrode 20 is formed such that both lengths in the height direction X and the width direction Y are smaller than both lengths in the height direction X and the width direction Y of the negative electrode 21. The length in the height direction X is the length of the region where the positive electrode active material is applied in the positive electrode 20, and the length of the region where the negative electrode active material is applied in the negative electrode 21. The separator 26 is formed such that both lengths in the height direction X and the width direction Y are larger than both lengths in the height direction X and the width direction Y of the negative electrode 21. That is, of the positive electrode 20, the negative electrode 21, and the separator 26 constituting the electrode assembly 12, the separator 26 is formed to be the largest.

  In the electrode assembly 12 according to the present embodiment, a facing portion 36 is projected onto the surfaces 12a and 12b which are both surfaces in the stacking direction, and a facing region where the positive electrode active material layer 23 and the negative electrode active material layer 25 are opposed to each other when viewed from the stacking direction. Have In the electrode assembly 12 of the present embodiment, a region other than the facing portion 36 is a non-facing portion 37 where the positive electrode active material layer 23 and the negative electrode active material layer 25 do not face each other.

  On the other hand, the adhesive tape 33 wound around the outer periphery of the electrode assembly 12 is formed such that the width direction along the height direction X of the separator 26 is larger than the length of the separator 26 in the height direction X. That is, the adhesive tape 33 of the present embodiment has a size that can cover both surfaces (surfaces 12a and 12b) in the stacking direction of the electrode assembly 12 in a state where there is no joint in the direction along the height direction X. Is formed. In the electrode assembly 12 of the present embodiment, as shown in FIG. 6A, the negative electrode 21 is stacked on the outermost side in the stacking direction of the electrode assembly 12. For this reason, both surfaces of the electrode assembly 12 in the stacking direction become the surfaces 12a and 12b of the negative electrode active material layer 25 on the outer side of the two negative electrodes 21 stacked on the outermost side.

  And the adhesive tape 33 is wound around the outer periphery of the electrode assembly 12 of this embodiment, as shown to Fig.6 (a)-(c). 6A to 6C, the positive electrode 20, the negative electrode 21, and the separator 26 are illustrated in a simplified manner.

  As shown in FIG. 6A, the electrode assembly 12 has a facing portion 36 of the positive electrode active material layer 23 and the negative electrode active material layer 25. The facing portion 36 projects the facing region of the positive electrode active material layer 23 and the negative electrode active material layer 25 as described above, and the facing region is formed in a region where the positive electrode active material layer 23 and the negative electrode active material layer 25 overlap in the stacking direction. Is done. The facing portion 36 is projected in a range where the positive electrode active material layer 23 and the negative electrode active material layer 25 overlap each other on the respective surfaces 12a and 12b of the negative electrode 21 stacked on the outermost side in the electrode assembly 12. On the other hand, in the electrode assembly 12, a region excluding the facing portion 36 becomes a non-facing portion 37 where the positive electrode active material layer 23 and the negative electrode active material layer 25 are not opposed in the stacking direction. The non-facing portion 37 is located outside the electrode assembly 12 with respect to the facing portion 36. In FIG. 5, in the region where the positive electrode 20, the negative electrode 21, and the separator 26 overlap in the stacking direction, the region excluding the positive electrode active material layer 23 of the positive electrode 20, that is, protrudes outward from the edge of the positive electrode active material layer 23. Each part of the negative electrode active material layer 25 of the negative electrode 21 and the separator 26 becomes a non-opposing portion 37. The non-facing portion 37 projects a non-facing region that continues in the stacking direction. Note that the four side surfaces 12 c to 12 f of the electrode assembly 12 also serve as non-opposing portions 37.

  Then, as shown in FIG. 6B, the adhesive tape 33 is wound around the outer periphery of the electrode assembly 12 from a state in which the starting end side 33 a that is the start of winding is attached to one side surface 12 c of the electrode assembly 12. That is, the adhesive tape 33 is attached to the outer periphery of the electrode assembly 12 while rotating the electrode assembly 12. More specifically, the electrode assemblies 12 are sequentially attached to the four surfaces (the surfaces 12a and 12b and the side surfaces 12c and 12d of the negative electrode active material layer 25) forming the outer periphery. In the present embodiment, the direction in which the adhesive tape 33 is wound is a direction orthogonal to the protruding direction of the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30. Then, as shown in FIG. 6 (c), the adhesive tape 33 is pasted with the end side 33b, which is the end of winding, overlapping the start side 33a on one side surface 12c of the electrode assembly 12 to which the start end side 33a is attached. wear. Thereby, the adhesive tape 33 is wound around the outer periphery of the electrode assembly 12. The adhesive tape 33 covers the facing portion 36. Moreover, the adhesive tape 33 becomes a ring shape by covering the entire circumference of the electrode assembly 12.

  In the electrode assembly 12 to which the adhesive tape 33 is attached in this manner, the connecting portion 38 that serves as a region where the start side 33a and the end side 33b of the adhesive tape 33 are bonded, that is, a region where both ends of the adhesive tape 33 are connected. , Facing one side surface 12 c of the electrode assembly 12. That is, the connecting portion 38 is located on the side surface 12c of the electrode assembly 12, that is, the non-facing portion 37 that is a region where the positive electrode active material layer 23 and the negative electrode active material layer 25 in the electrode assembly 12 do not overlap in the stacking direction. In other words, the adhesive tape 33 is placed on the electrode assembly 12 such that the connecting portion 38 is disposed at a position avoiding the facing portion 36 that is a region where the positive electrode active material layer 23 and the negative electrode active material layer 25 overlap in the stacking direction. It is rolled up. Thereby, the adhesive tape 33 is affixed on the surfaces 12a and 12b of the negative electrode active material layer 25 which are both surfaces in the stacking direction of the electrode assembly 12 in a state where there are no joints or steps. Further, both surfaces of the electrode assembly 12 in the stacking direction are surfaces that receive a restraining load when the assembled battery 34 is formed. For this reason, in the electrode assembly 12 of this embodiment, the connection part 38 is not located in the surface which receives a restraint load.

  The adhesive tape 33 is wound around the outer periphery of the electrode assembly 12. The adhesive tape 33 wound around the electrode assembly 12 is a strip-shaped tape having a start end side 33a and a end end side 33b. By using the strip-shaped tape, the connecting portion 38 faces one place of the one side surface 12 c of the electrode assembly 12. Further, since there is no opposing positive electrode active material layer 23 on the surface 12a, 12b side of the negative electrode active material layer 25 which is both surfaces of the electrode assembly 12 in the stacking direction, the negative electrode active material layer 25 having the surfaces 12a, 12b. Does not contribute to the chemical reaction of the battery. For this reason, you may affix the adhesive tape 33 on the surfaces 12a and 12b.

Hereinafter, the operation of the present embodiment will be described.
An insulating adhesive tape 33 having an insulating property is wound around the outer periphery of the electrode assembly 12. For this reason, when the electrode assembly 12 is accommodated in the metal case 11, insulation with the case 11 is ensured. Further, the electrode assembly 12 is wound on the outer periphery with the adhesive tape 33, whereby the stacked state of the positive electrode 20, the negative electrode 21 and the separator 26 is maintained.

  Moreover, as shown in FIG. 4, when the assembled battery 34 is comprised with the secondary battery 10 of this embodiment, a restraint load acts from the side surface 13b, 13c side of the case 11, as mentioned above. This restraining load acts in the stacking direction of the electrode assembly 12 accommodated in the case 11. However, in the electrode assembly 12 of the present embodiment, the adhesive tape 33 is attached in a state where there are no joints or steps on both surfaces in the stacking direction. For this reason, the restraining load is almost uniformly applied to both surfaces of the electrode assembly 12 in the stacking direction. That is, a local load, that is, an uneven load is suppressed from acting on both surfaces of the electrode assembly 12 in the stacking direction. As a result, even when the adhesive tape 33 is used for the purpose of fixing the electrode assembly 12 and ensuring insulation, the deposition of metal ions (lithium ions) due to the increased surface pressure at the location where the adhesive tape 33 is applied. It is suppressed. The connecting portion 38 of the adhesive tape 33 faces the side surface 12c of the electrode assembly 12, but no restraining load is applied to the side surface 12c.

  In addition, when the outer dimension of the electrode assembly 12 is substantially the same as the inner dimension of the case 11 (main body member 13) and the electrode assembly 12 is accommodated in the case 11, the electrode assembly 12 is also restrained from the case 11. Will receive a load. However, if the configuration of the electrode assembly 12 of the present embodiment is used, it is possible to suppress the surface pressure from being locally increased at the facing portion 36.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) The connecting portion 38 of the sheet member (the adhesive tape 33 in the embodiment) is disposed in the non-facing portion 37 other than the facing portion 36 where the positive electrode active material layer 23 and the negative electrode active material layer 25 overlap in the stacking direction. For this reason, in the case of the assembled battery 34, even when a restraining load is applied to fix each secondary battery 10, the surface pressure is locally increased at the facing portion 36 between the positive electrode active material layer 23 and the negative electrode active material layer 25. Is suppressed from increasing. As a result, the deposition of metal ions (lithium ions in the embodiment) from the active material layer in the facing portion 36 is suppressed. Therefore, a decrease in the performance of the secondary battery 10 can be suppressed.

  (2) Since the connecting portion 38 faces the side surface 12 c of the electrode assembly 12, it is reliably prevented that the surface pressure is locally increased at the facing portion 36 between the positive electrode active material layer 23 and the negative electrode active material layer 25. it can.

(3) Since the insulating sheet member (adhesive tape 33 in the embodiment) is wound around the outer periphery of the electrode assembly 12, the insulating property of the electrode assembly 12 can be suitably ensured.
(4) Since the adhesive tape 33 is wound around the outer periphery of the electrode assembly 12, the operation of covering the electrode assembly 12 can be simplified. Further, by using the adhesive tape 33, unlike the joining by heat, it is not necessary to consider the influence of the thermal contraction or shutdown of the separator 26, and the workability is good.

  (5) The stacked state of the positive electrode 20, the negative electrode 21 and the separator 26 constituting the electrode assembly 12 can be fixed by the adhesive tape 33. As a result, the insertability of the electrode assembly 12 into the case 11 can be improved.

  (6) By mounting the secondary battery 10 of this embodiment on a vehicle, for example, it is possible to reduce the influence on the running performance of the vehicle. That is, since the deterioration of the performance of the secondary battery 10 is suppressed, power can be stably supplied from the secondary battery 10.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. In the embodiments described below, the same components as those in the embodiments already described are denoted by the same reference numerals, and the redundant description thereof is omitted or simplified.

  As shown in FIGS. 7 and 8, the outer periphery of the electrode assembly 12 of this embodiment is covered with a first insulating film 43 as a first sheet member and a second insulating film 44 as a second sheet member. It has been broken. The first insulating film 43 covers the surface 12a, the side surface 12c, the side surface 12d, and the side surface 12f among the six surfaces of the electrode assembly 12. On the other hand, the second insulating film 44 covers the surface 12 b of the six surfaces of the electrode assembly 12. That is, in the electrode assembly 12 of the present embodiment, of all the six surfaces, five surfaces excluding the side surface 12e from which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude are the first insulating film 43 and the second surface. It is covered with an insulating film 44.

  In the electrode assembly 12 covered with the first and second insulating films 43 and 44, the connecting portion 45 serving as a region for connecting the first and second insulating films 43 and 44 is connected to the non-facing portion 37. It faces the side surface 12c, the side surface 12d, and the side surface 12f. That is, the connecting portion 45 faces the three side surfaces 12c, 12d, and 12f in the electrode assembly 12 of the present embodiment. In each connecting portion 45, as shown in FIG. 8, the end portions of the first and second insulating films 43, 44 are folded on the non-facing portion 37 (side surfaces 12c, 12d, 12f) side. Then, the end portions of the folded first and second insulating films 43 and 44 are bonded to each connecting portion 45 with an adhesive tape 46. The adhesive tape 46 is affixed so as to be located in the non-facing portion 37.

  In the electrode assembly 12 on which the first and second insulating films 43 and 44 are wound as described above, there are no joints or steps on the surfaces 12a and 12b of the electrode assembly 12 serving as the facing portion 36. That is, in the electrode assembly 12 of this embodiment, the first and second insulating films 43 and 44 are wound so that the connecting portion 45 is disposed at a position avoiding the facing portion 36.

Hereinafter, a method for manufacturing the electrode assembly 12 in this embodiment, more specifically, a procedure for winding the first and second insulating films 43 and 44 will be described with reference to FIGS. 9 to 13.
As shown in FIG. 9, the first insulating film 43 having a quadrangular shape covers the first sheet surface 43a covering the surface 12a of the electrode assembly 12, the second sheet surface 43b covering the side surface 12c, and the side surface 12d. A third sheet surface 43c and a fourth sheet surface 43d covering the side surface 12f are provided. The size of the first sheet surface 43 a is set to be approximately the same as the size of the negative electrode 21 that is the outermost layer of the electrode assembly 12. The sizes of the second to fourth sheet surfaces 43b to 43d are set in consideration of the thickness and folding allowance of the electrode assembly 12.

  Then, the first insulating film 43 is set on a first jig 47 configured in consideration of the outer dimension of the electrode assembly 12. As shown in FIG. 9, the first jig 47 has a square bottom wall 47a and three side walls 47b, 47c, 47d erected from three sides of the bottom wall 47a. The side wall 47b and the side wall 47c are walls facing each other, and the side wall 47d is a wall provided continuously to the side wall 47b and the side wall 47c. The first jig 47 has a space S surrounded by a bottom wall 47a and three side walls 47b to 47d erected on the bottom wall 47a. The first jig 47 has a box shape having an opening K1 on the side facing the bottom wall 47a and an opening K2 on the side facing the side wall 47d. The first insulating film 43 has a first sheet surface 43a on the bottom wall 47a of the first jig 47, a second sheet surface 43b on the side wall 47b of the first jig 47, and a third sheet surface 43c on the first. The fourth sheet surface 43d is set on the side wall 47c of the first jig 47 so as to correspond to the side wall 47d of the first jig 47, respectively. At this time, the first insulating film 43 is bent along the fold line T so as to be along the boundary between the bottom wall 47a of the first jig 47 and the side walls 47b to 47d. As a result, the first insulating film 43 is set so as to face the inner surfaces of the bottom wall 47a and the side walls 47b to 47d of the first jig 47 as shown in FIGS. ).

  Next, after the first insulating film 43 is set, the positive electrode 20, the negative electrode 21, and the separator 26 are interposed between the positive electrode 20 and the negative electrode 21 in the space S of the first jig 47. The laminated body 48 thus laminated is accommodated (lamination process). The stacked body 48 may be accommodated in the space S by sequentially stacking the positive electrode 20, the negative electrode 21, and the separator 26 in the first jig 47, or may be manufactured in a separate process and stored in the space S. May be accommodated. The stacked body 48 is accommodated in the space S of the first jig 47 so that the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 are located on the opening K2 side of the first jig 47. As a result, the first jig 47 has a surface on the bottom wall 47a that serves as the surface 12a of the electrode assembly 12, surfaces on the side walls 47b and 47c that serve as the side surfaces 12c and 12d of the electrode assembly 12, and electrodes on the side wall 47d. The stacked body 48 is accommodated so that the surfaces to be the side surfaces 12f of the assembly 12 are respectively positioned. On the other hand, the laminated body 48 accommodated in the first jig 47 is an electrode (negative electrode) which is located on the side opposite to the surface 12a located on the first insulating film 43 side and constitutes the outermost layer of the electrode assembly 12. 21) is exposed to the opening K1 side. Then, the second insulating film 44 is set on the surface 12b exposed on the opening K1 side.

  As shown in FIG. 10, the second insulating film 44 having a quadrangular shape is connected to the first sheet surface 44 a covering the surface 12 b of the electrode assembly 12 and three sides of the first sheet surface 44 a. A second sheet surface 44b, a third sheet surface 44c, and a fourth sheet surface 44d that protrude from the three sides are provided. The size of the first sheet surface 44 a is set to be approximately the same as the size of the negative electrode 21 that is the outermost layer of the electrode assembly 12. The 2nd sheet surface 44b is a surface arrange | positioned at the side wall 47b side of the 1st jig | tool 47, and is a surface adhere | attached with the 2nd sheet surface 43b of the 1st insulating film 43 set facing the side wall 47b. It is. The third sheet surface 44c is a surface disposed on the side wall 47c side of the first jig 47, and is a surface bonded to the third sheet surface 43c of the first insulating film 43 set facing the side wall 47c. It is. The 4th sheet surface 44d is a surface arrange | positioned at the side wall 47d side of the 1st jig | tool 47, and is the surface adhere | attached with the 4th sheet surface 43d of the 1st insulating film 43 set facing the side wall 47d. It is.

  And the laminated body 48 accommodated in the 1st jig | tool 47 is pressed by the 2nd jig | tool 49 from the opening part K1 side of the 1st jig | tool 47 (pressing process). As shown in FIGS. 11 and 12, the second jig 49 has a rectangular parallelepiped block shape and includes a pressing surface 49 a that presses the stacked body 48. The pressing surface 49 a of the second jig 49 is set to approximately the same size as the negative electrode 21 that is the outermost layer of the electrode assembly 12. An adsorption mechanism G is connected to the second jig 49, and the second insulating film 44 is adsorbed to the pressing surface 49a by the action of the adsorption mechanism G. The second insulating film 44 is bent along the fold line T so as to be along the boundary with the pressing surface 49 a of the second jig 49. In this state, the second jig 49 is positioned with respect to the opening K1 of the first jig 47, and the laminate 48 housed in the first jig 47 is pressed as shown in FIG. In this pressing step, the second insulating film 44 is positioned on the opposite side of the stacked body 48 from the pressing surface 49a of the second jig 49 and the first insulating film 43 (negative electrode). It is interposed between the electrodes 21).

  In the pressing step, the second jig 49 is pressed and moved until the thickness of the stacked body 48 reaches the thickness of the electrode assembly 12. And the laminated body 48 sinks so that it may receive thickness from the 2nd jig | tool 49, and thickness may reduce. When the thickness of the laminated body 48 decreases, the second insulating film 44 adsorbed on the pressing surface 49a of the second jig 49 is disposed on the inner surface of the first jig 47 as shown in FIG. It overlaps with the first insulating film 43 covering 48. And if the thickness of the laminated body 48 becomes the thickness of the electrode assembly 12, the movement of the 2nd jig | tool 49 will be stopped and a position will be maintained in the state which gave the pressing force. That is, in this state, the pressing force from the second jig 49 is continuously applied to the stacked body 48.

  Thereafter, the side walls 47b to 47d of the first jig 47 are tilted outward. In FIG. 12, the collapsed side walls 47b to 47d are indicated by two-dot chain lines. When the side walls 47b to 47d are tilted down, the stacked body 48 (electrode assembly 12) in the first jig 47 appears with the side surfaces 12c, 12d, and 12f covered with the first insulating film 43.

  And as shown in FIG. 13, in the state which the edge part of the 1st insulating film 43 and the edge part of the 2nd insulating film 44 were piled up, it folds | folds outward. Specifically, as shown by a two-dot chain line in FIG. 13, the end portions of the first and second insulating films 43 and 44 are folded toward the side surfaces 12 c, 12 d, and 12 f of the electrode assembly 12. In the folded state, the end portion of the second insulating film 44 covers the end portion of the first insulating film 43 that is folded outward. Thereafter, the folded first and second insulating films 43 and 44 are bonded with an adhesive tape 46 as shown in FIGS.

  Accordingly, the first and second insulating films 43 and 44 are wound around the outer periphery of the electrode assembly 12. In the electrode assembly 12 around which the first and second insulating films 43 and 44 are wound, the connecting portion 45 of the first and second insulating films 43 and 44 has a side surface 12c and a side surface 12d that become the non-opposing portion 37. And the side surface 12f.

Hereinafter, the operation of the present embodiment will be described.
Insulating first and second insulating films 43 and 44 are wound around the outer periphery of the electrode assembly 12. For this reason, when the electrode assembly 12 is accommodated in the metal case 11, insulation with the case 11 is ensured. In addition, the electrode assembly 12 is maintained in the laminated state of the positive electrode 20, the negative electrode 21, and the separator 26 by winding the outer periphery with the first and second insulating films 43 and 44.

  The electrode assembly 12 is wound with the first and second insulating films 43 and 44 in a state where there are no joints or steps on both surfaces in the stacking direction. For this reason, the restraining load is almost uniformly applied to both surfaces of the electrode assembly 12 in the stacking direction. That is, a local load, that is, an uneven load is suppressed from acting on both surfaces of the electrode assembly 12 in the stacking direction.

  Therefore, according to this embodiment, in addition to the effects (1) to (6) of the first embodiment, the following effects can be obtained. Note that the effects (1) to (6) described above in the present embodiment can be produced by employing the first and second insulating films 43 and 44 instead of the adhesive tape 33.

  (7) Since the first and second insulating films 43 and 44 are wound using the first and second jigs 47 and 49, the manufacturing process of the electrode assembly 12 can be simplified. In addition, the first and second insulating films 43 and 44 can be neatly wound around the electrode assembly 12 so as not to cause misalignment or wrinkles.

  (8) The side surface 12e of the electrode assembly 12 from which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude is opened without being covered with the first and second insulating films 43 and 44. For this reason, the permeability of the electrolytic solution in the electrode assembly 12 can be increased. In addition, it is possible to easily release the gas generated when the secondary battery 10 is used.

In addition, you may change the said embodiment as follows.
As shown to Fig.14 (a), you may wrap the electrode assembly 12 with the insulating film 40 as a sheet | seat member. The insulating film 40 is made of, for example, polypropylene (PP). The insulating film 40 is formed in a sheet shape and wraps the electrode assembly 12 with one insulating film 40. Specifically, the insulating film 40 includes both surfaces (surfaces 12a and 12b) in the stacking direction of the electrode assembly 12, and side surfaces 12f facing the side surfaces 12e from which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude. , The sheet portion 41 covering the. And when the insulating film 40 is used, as shown in FIG.14 (b), the edge parts 40a and 40b of the insulating film 40 are joined with both the side surfaces 12c and 12d of the electrode assembly 12. FIG. Thereby, the connection part 38 of the insulating film 40 faces the side surfaces 12c and 12d. The connecting portion 38 of this other example is welded. The insulating film 40 is formed in a size that covers each surface of the electrode assembly 12 except for the side surface 12e from which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude. When the end portions 40a and 40b of the insulating film 40 are joined together as described above, the insulating film 40 has a bottomed bag shape, and the electrode assembly 12 is accommodated in the case 11 while being accommodated in the bottomed bag shaped insulating film 40. Be contained.

  Further, in another example shown in FIGS. 14A and 14B, after the electrode assembly 12 is wrapped with the insulating film 40, both sides of the electrode assembly 12 in the stacking direction of the electrode assembly 12 are formed by hot press molding ( It may be welded to the surfaces 12a, 12b). The temperature at the time of hot press molding is set to a temperature lower than the melting temperature of the separator 26 so that the separator 26 constituting the electrode assembly 12 does not shut down.

  Further, in another example shown in FIGS. 14A and 14B, a thermosetting adhesive is applied to both surfaces (surfaces 12a and 12b) in the stacking direction of the electrode assembly 12, and the insulating film 40 is electroded by heating. It may be adhered to the assembly 12. The thermosetting adhesive is an adhesive that cures at a temperature lower than the melting temperature of the separator 26.

  In the first embodiment, as shown in FIG. 15, the adhesive tape 33 is pasted so that the joining portions 38 of the adhesive tape 33 face both surfaces (surfaces 12 a and 12 b) of the electrode assembly 12 in the stacking direction. May be attached. In FIG. 15, the connecting portion 38 faces the surface 12a. In other words, as long as the connecting portion 38 is positioned in the non-facing portion 37, the connecting portion 38 is not limited to the side surfaces 12 c and 12 d of the electrode assembly 12, and may face both sides of the electrode assembly 12 in the stacking direction. FIG. 15 illustrates an example in which the connecting portion 38 is disposed at a position corresponding to the uncoated portion 42 of the negative electrode 21. In addition, the connection part 38 should just be located in the non-opposing part 37 as mentioned above. For this reason, the connecting portion 38 may be disposed at a position corresponding to the negative electrode active material layer 25 that does not overlap the positive electrode active material layer 23.

  In the first embodiment, the connecting portion 38 is formed by the adhesive force of the adhesive tape 33, but may be bonded by an adhesive. That is, when forming the connecting portion 38, the method may be appropriately changed according to the sheet member wound around the electrode assembly 12. For example, adhesion, welding, or locking may be used.

  In the first embodiment, the pressure-sensitive adhesive tape 33 may have a pressure-sensitive adhesive surface in the region of the start end side 33a at the beginning of winding and the region of the end side 33b at the end of winding. That is, the entire region corresponding to the outer periphery of the electrode assembly 12 need not be an adhesive surface.

  In the first embodiment, the connecting portion 38 may face both side surfaces 12c and 12d of the electrode assembly 12. In this case, two adhesive tapes 33 are used. And in each side surface 12c, 12d, the end side of one adhesive tape 33 and the end side of the other adhesive tape 33 are piled up.

  In the electrode assembly 12, the side surface 12f facing the side surface 12e from which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude has an insulating member (insulating sheet) as long as there is sufficient clearance between the case 11 and Etc.) may not be provided. Further, an insulating member may be provided even when there is a clearance. In addition, when providing an insulating member, the insulating member may be provided in the electrode assembly 12 side, and may be provided in the surface of case 11 facing the surface. For example, in the first embodiment, the adhesive tape 33 may be used.

  In the first embodiment, the winding direction of the adhesive tape 33 in the electrode assembly 12 may be changed. Specifically, the adhesive tape 33 is wound along the protruding direction of the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30. In this case, the connecting portion 38 may be formed on either the side surface 12e from which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude or the side surface 12f facing the surface. It is easier to form on the side surface 12f where the electric tab 30 does not exist. In this case, it is not necessary to provide an insulating member (such as an insulating sheet) on both side surfaces 12c and 12d of the electrode assembly 12 as long as a sufficient clearance exists between the electrode assembly 12 and the case 11. Further, an insulating member may be provided even when there is a clearance. In addition, when providing an insulating member, the insulating member may be provided in the electrode assembly 12 side, and may be provided in the surface of case 11 facing the surface. For example, in the first embodiment, the adhesive tape 33 may be used.

  In the first embodiment, an insulating member may be disposed on the inner surface of the case 11 (main body member 13), and the electrode assembly 12 to which the adhesive tape 33 described in the embodiment is attached may be accommodated.

  In 2nd Embodiment, as shown in FIG. 16, the connection part 45 of the 1st, 2nd insulating films 43 and 44 faces both surfaces (surface 12a, 12b) of the lamination direction of the electrode assembly 12. As shown in FIG. As described above, the first and second insulating films 43 and 44 may be wound. In other words, as long as the connecting portion 45 is positioned in the non-opposing portion 37, the connecting portion 45 may face not only the side surfaces 12 c, 12 d, and 12 f of the electrode assembly 12 but also both sides of the electrode assembly 12 in the stacking direction. . The ends of the first and second insulating films 43 and 44 are folded inward from the state shown in FIG. In the case of this another example, the end portions of the folded first and second insulating films 43 and 44 and the adhesive tape 46 do not overlap the positive electrode 20, that is, the facing portion 36. Is set. Also, as shown in FIG. 12, the size of the pressing surface 49a of the second jig 49 is two in FIG. 16 so that the end portion can be folded and bonded while the laminate 48 is pressed by the second jig 49. As shown by the dotted line, the size is made smaller than the size of the negative electrode 21.

  In the second embodiment, the first insulating film 43 and the second insulating film 44 may be a single insulating film 60 as shown in FIG. In this case, the insulating film 60 includes a sheet surface 60 a corresponding to the first insulating film 43 and a sheet surface 60 b corresponding to the second insulating film 44. Similar to the first insulating film 43, the sheet surface 60a includes a first sheet surface 43a, a second sheet surface 43b, a third sheet surface 43c, and a fourth sheet surface 43d. On the other hand, the sheet surface 60b has a first sheet surface 44a, a second sheet surface 44b, and a third sheet surface 44c of the second insulating film 44, and the first sheet surface 44a is a fourth sheet of the sheet surface 60a. It is connected to the surface 43d. When the insulating film 60 is used, the sheet surface 60 a is disposed on the inner surface of the first jig 47. And after accommodating the laminated body 48 in the 1st jig | tool 47, after covering the sheet | seat surface 60b on the surface 12b of the laminated body 48, it presses with the 2nd jig | tool 49. FIG. In addition, in the case of the insulating film 60, the connection part 45 faces two places of the side surfaces 12c and 12d.

  In the second embodiment, as shown in FIG. 18, the side surface 12 e of the electrode assembly 12 from which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude is formed by the first and second insulating films 43 and 44. It may be covered. In this case, as shown in FIG. 19A, the first insulating film 43 has the fifth sheet surface 43e as the first sheet surface so as to avoid the positions of the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30. 43a is connected. Further, as shown in FIG. 19B, the fifth sheet surface 44e is formed on the second insulating film 44 so as to avoid the positions of the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30. Connect to And as demonstrated in 2nd Embodiment, after winding the 1st, 2nd insulating films 43 and 44 around the laminated body 48 using the 1st jig | tool 47 and the 2nd jig | tool 49, it is the 5th sheet | seat. The surface 43e and the fifth sheet surface 44e are folded toward the side surface 12e, and the fifth sheet surfaces 43e and 44e are overlapped. Thereby, the connection part 45 faces the side surface 12e. Then, the fifth sheet surfaces 43 e and 44 e are bonded with the adhesive tape 46. As in this alternative example, the entire surface of the electrode assembly 12 is covered by covering the side surface 12e from which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude with the first and second insulating films 43 and 44. Therefore, higher insulation (safety) can be realized.

  (Circle) in 2nd Embodiment, the adhesive tape 46 may be affixed over the full length of the connection part 45, and may be affixed on one part. Moreover, in 2nd Embodiment, you may adhere | attach the edge part of the 1st, 2nd insulating films 43 and 44 with an adhesive agent.

  In the second embodiment, the first jig 47 may be provided with an adsorption mechanism G to adsorb the first insulating film 43. In this way, it is possible to suppress the displacement of the first insulating film 43 in the first jig 47.

In the second embodiment, the second insulating film 44 may be covered with the surface 12 b of the laminated body 48 accommodated in the first jig 47 and then pressed by the second jig 49.
In the second embodiment, the first and second insulating films 43 and 44 may be provided with an adhesive surface. Then, the first and second insulating films 43 and 44 are adhered to the surfaces 12a and 12b and the side surfaces 12c, 12d and 12f of the electrode assembly 12, and the first and second insulating films 43 and 44 are attached to their own. You may make it adhere with adhesive force.

  In the first and second embodiments, the sizes of the positive electrode 20, the negative electrode 21, and the separator 26 may be changed. For example, the negative electrode 21 and the separator 26 may be the same size. That is, as long as the entire area of the positive electrode active material layer 23 overlaps the negative electrode active material layer 25, the sizes of the negative electrode 21 and the separator 26 may be the same or different.

  In the first and second embodiments, the separator 26 may be formed in a bag shape. Then, the positive electrode 20 may be accommodated in the bag-like separator 26 and overlapped with the negative electrode 21.

  In the first and second embodiments, the shapes of the positive electrode 20, the negative electrode 21, and the separator 26 may be changed. For example, it may be formed in a square in front view. Moreover, the joining form of the positive electrode current collecting tab 28 (positive electrode current collecting group 31) and the negative electrode current collecting tab 30 (negative electrode current collecting group 32), and the positive electrode terminal 15 and the negative electrode terminal 16 is not limited to the configuration of the embodiment, and is arbitrary. You may change to For example, the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 may be joined to the positive electrode terminal 15 and the negative electrode terminal 16 without forming the current collecting group. Further, the number of current collecting groups formed in the electrode assembly 12 and the shapes of the positive electrode terminal 15 and the negative electrode terminal 16 may be arbitrarily changed.

  In the first and second embodiments, the positive electrode active material layer 23 may be formed on one side of the positive electrode metal foil 22. Similarly, the negative electrode active material layer 25 may be formed on one surface of the negative electrode metal foil 24. When the outermost negative electrode active material layer 25 is eliminated from the electrode assembly 12, both surfaces in the stacking direction of the electrode assembly 12 become the surface of the negative electrode metal foil 24.

(Circle) the secondary battery 10 of 1st, 2nd embodiment may be mounted in a motor vehicle as a vehicle, and may be mounted in an industrial vehicle. Further, the present invention may be applied to a stationary power storage device.
The configurations of the first and second embodiments may be applied to other power storage devices such as electric double layer capacitors.

  The secondary battery 10 of the first and second embodiments is a lithium ion secondary battery, but is not limited to this, and may be another secondary battery. In short, any ion may be used as long as ions move between the positive electrode active material layer and the negative electrode active material layer and transfer charge.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery, 11 ... Case, 12 ... Electrode assembly, 12a, 12b ... Surface, 12c-12f ... Side surface, 20 ... Positive electrode, 21 ... Negative electrode, 22 ... Positive electrode metal foil, 23 ... Positive electrode active material layer 24 ... Negative electrode metal foil, 25 ... Negative electrode active material layer, 26 ... Separator, 28 ... Positive electrode current collecting tab, 30 ... Negative electrode current collecting tab, 33, 46 ... Adhesive tape, 37 ... Non-opposing part, 38, 45 ... Connection Part, 40, 60 ... insulating film, 41 ... sheet part, 43 ... first insulating film, 44 ... second insulating film, 47 ... first jig, 47a ... bottom wall, 47b-47d ... side wall, 48 ... Laminated body 49 ... second jig 49a ... pressing surface S ... space G ... adsorption mechanism.

Claims (17)

A positive electrode having a positive electrode active material layer coated with a positive electrode active material on a positive electrode metal foil and a positive electrode current collecting tab protruding from one end of the positive electrode metal foil; a negative electrode active material layer coated with a negative electrode active material on the negative electrode metal foil; A negative electrode electrode having a negative electrode current collecting tab protruding from one end of the negative electrode metal foil, and insulating the gap between the positive electrode and the negative electrode, and laminating them to form a layered electrode assembly In the power storage device housed in
An insulating sheet member covering both sides of the electrode assembly in the stacking direction;
The electrode assembly includes a facing portion where a facing region where the positive electrode active material layer and the negative electrode active material layer are opposed to each other when viewed from the stacking direction is projected on both surfaces in the stacking direction, and a non-facing portion other than the facing portion. And
A power storage device, wherein a connecting portion that connects the sheet members faces the non-facing portion. The non-opposing portion includes a side surface of the electrode assembly perpendicular to the stacking direction of the electrode assembly,
The power storage device according to claim 1, wherein the connecting portion faces the side surface.   The sheet member includes both surfaces of the electrode assembly including the entire surface of the facing portion, and both sides orthogonal to the current collecting side surface from which the positive electrode current collecting tab and the negative electrode current collecting tab protrude among the side surfaces of the electrode assembly. The power storage device according to claim 2 covering a surface.   The power storage device according to claim 3, wherein the sheet member is annular.   The power storage device according to any one of claims 1 to 4, wherein the sheet member is an adhesive tape.   The sheet member is bonded to both surfaces in the stacking direction of the electrode assembly with a thermosetting adhesive that cures at a temperature lower than a melting temperature of a separator that insulates between the positive electrode and the negative electrode. The electrical storage apparatus as described in any one of Claims 1-4. The positive electrode current collecting tab and the negative electrode current collecting tab protrude in the same direction from one current collecting side surface from which the positive electrode current collecting tab and the negative electrode current collecting tab protrude among the side surfaces of the electrode assembly,
The sheet member has a sheet portion that covers both surfaces of the electrode assembly in the stacking direction and an opposite surface facing the current collector side surface, and both side surfaces orthogonal to the current collector side surface of the sheet portion. The power storage device according to any one of claims 1 to 3, wherein the connecting portion faces and is formed in a bottomed bag shape. The sheet member includes a first sheet member and a second sheet member,
The power storage device according to any one of claims 1 to 3, wherein the first sheet member and the second sheet member are bonded together at the connecting portion.   The power storage device according to claim 8, wherein the sheet member covers an opposite surface facing the current collector side surface in addition to both surfaces of the electrode assembly and both side surfaces orthogonal to the current collector side surface.   The power storage device according to claim 9, wherein the sheet member does not cover the current collector side surface.   The power storage device according to claim 9, wherein the sheet member further covers the current collecting side surface.   The power storage device according to any one of claims 8 to 11, wherein the first sheet member and the second sheet member are bonded with an adhesive tape.   The power storage device according to any one of claims 1 to 12, wherein the power storage device is a secondary battery. An electrode assembly in which a positive electrode having a positive electrode active material layer coated with a positive electrode active material on a positive electrode metal foil and a negative electrode having a negative electrode active material layer coated with a negative electrode active material on a negative electrode metal foil are insulated and laminated In the manufacturing method of
The electrode assembly includes a facing portion where a facing region where the positive electrode active material layer and the negative electrode active material layer are opposed to each other when viewed from the stacking direction is projected on both surfaces in the stacking direction, and a non-facing portion other than the facing portion. And
A sheet in which an insulating first sheet member is set on the inner surface of the bottom wall of each first jig and the inner surface of each side wall having a space surrounded by a rectangular bottom wall and a side wall erected from three sides of the bottom wall A set process;
After setting the first sheet member, a laminating step for accommodating a laminate in which a separator is interposed between the positive electrode and the negative electrode in the space of the first jig, and laminating these,
An insulating second sheet member is interposed between the pressing surface of the second jig for pressing the laminate and the electrode constituting the outermost layer located on the opposite side of the laminate from the first sheet member. And then pressing the laminate with the second jig,
An electrode assembly manufacturing method comprising: an adhesion step of folding the end portion of the first sheet member and the end portion of the second sheet member and bonding the end portion to the non-facing portion. The non-facing portion includes a side surface of the electrode assembly perpendicular to the stacking direction of the electrode assembly,
The method of manufacturing an electrode assembly according to claim 14, wherein an end portion of the first sheet member and an end portion of the second sheet member are folded toward the side surface and bonded facing the side surface. .   The end portion of the first sheet member and the end portion of the second sheet member are folded toward the electrode constituting the outermost layer, and the other than the facing portion on both surfaces in the stacking direction of the electrode assembly. The method of manufacturing an electrode assembly according to claim 14, wherein the electrode assembly is bonded facing the non-opposing portion.   The first sheet member is adsorbed by the first jig, and the second sheet member is adsorbed by the second jig. Manufacturing method of electrode assembly.