JP2015088605A - Method of manufacturing power storage device and power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly pre-dope lithium ions to a negative-electrode active material on each of negative-electrode collectors that are stacked, without increasing collector resistance and working man-hours.SOLUTION: A method of manufacturing a power storage device includes: a first step of forming an internal stack 3 by alternately stacking negative-electrode units 31 and positive-electrode units 32 with internal separators 331 interposed therebetween; a second step of forming a power storage unit 2 by covering the internal stack with an outside negative-electrode unit 4 so that an outside negative-electrode active material 42 of the outside negative-electrode unit 4 faces both end surfaces of the internal stack 3 and metallic lithium faces a side surface of the internal stack 3; a third step of electrically connecting all negative-electrode collectors 311 and outside negative-electrode collector 41 in the power storage unit 2; and a fourth step of pre-doping the metallic lithium to a negative-electrode active material 312 and the outside negative-electrode active material 42 by soaking the power storage unit 2 in a nonaqueous electrolyte 5.

Description

  The present invention relates to a method for manufacturing an electricity storage device and an electricity storage device. The present invention particularly relates to a method of manufacturing a lithium ion capacitor or a lithium battery predoped with lithium ions.

  As an electricity storage device having both good charge / discharge characteristics and high energy density, a lithium ion capacitor has attracted attention. The lithium ion capacitor is charged and discharged by a physical action by forming an electric double layer on the positive electrode side, and charged and discharged by a chemical reaction of lithium on the negative electrode side. In this case, in order to improve energy density, lithium ions are occluded (pre-doped) in advance in the negative electrode active material on the negative electrode side. Various proposals have been made on how to uniformly and rapidly perform lithium ion pre-doping.

  Patent Document 1 discloses a lithium ion capacitor in which fine holes are formed in a positive electrode current collector and a negative electrode current collector. According to this, lithium ions eluted in the electrolyte during pre-doping migrate in the stacking direction of each electrode plate through the fine holes formed in the positive electrode current collector and the negative electrode current collector. For this reason, lithium ions are uniformly pre-doped in the negative electrode active material provided in the laminated negative electrode current collector. Moreover, the manufacturing method of the lithium ion capacitor described in Patent Document 2 applies the negative electrode active material to a portion other than the central portion of the surface of the negative electrode current collector, and applies to the central portion where the negative electrode active material is not applied. A step of attaching metallic lithium. Lithium in the negative electrode active material applied to the negative electrode current collector is obtained by elution of the lithium metal attached to the central portion of the negative electrode current collector during the pre-doping into the electrolyte solution as lithium ions and migrating in the electrolyte solution. Ions are pre-doped.

Patent No. 4015993 JP 2008-60130 A

(Problems to be solved by the invention)
The diameter of the fine holes formed in the positive electrode current collector and the negative electrode current collector of the lithium ion capacitor described in Patent Document 1 is about 30 μm, and the aperture ratio is about 30%. Since a very large number of fine holes are formed in the current collector, the strength of the current collector, and consequently the strength of the lithium ion capacitor, is reduced. In addition, since a very large number of fine holes are formed in the current collector, a straight current collection path is not formed on the current collector, and a current collection path that is tortuous and narrow is formed. Resistance during power increases. Therefore, the energy loss due to the increase in internal resistance is large. Further, according to the method described in Patent Document 2, when a plurality of negative electrode current collectors are stacked, it is necessary to attach metal lithium to each of the stacked negative electrode current collectors, which may increase the number of work steps. There is. Moreover, since metallic lithium is pasted to the place where the negative electrode active material is originally applied, the amount of the negative electrode active material is reduced, which may reduce the energy density.

  The present invention relates to a method of manufacturing an electricity storage device capable of uniformly pre-doping lithium ions to a negative electrode active material on each of the stacked negative electrode current collectors without increasing current collection resistance and work man-hours, and such electricity storage. The purpose is to provide a device.

(Means for solving the problem)
The present invention relates to a negative electrode unit having a flat negative electrode current collector and a negative electrode active material provided on both sides of the negative electrode current collector, and a positive electrode provided on both sides of the flat positive electrode current collector and the positive electrode current collector. A positive electrode unit having an active material is alternately laminated with separators interposed therebetween, so that a first step for forming an internal laminate and a first portion, a second portion, and a third portion are formed in this order. The outer flat negative electrode current collector, the outer negative electrode active material provided on one surface of the first part and the third part, and the outer negative electrode active material of the outer negative electrode unit having metallic lithium provided on the second part are contained inside. An electric storage unit having an inner laminate and an outer negative electrode unit is formed by covering the inner laminate with the outer negative electrode unit so that the metal lithium faces the side surfaces of the inner laminate and facing both end faces of the laminate. Do Two steps, a third step of electrically connecting all the negative electrode current collectors and the outer negative electrode current collectors in the power storage unit, and all the negative electrode current collectors and the outer negative electrode current collectors in the third step And a fourth step of pre-doping metallic lithium into the negative electrode active material and the outer negative electrode active material by immersing the power storage unit electrically connected to each other in an electrolytic solution.

  According to the present invention, the metallic lithium provided in the outer negative electrode unit is disposed so as to face the side surface of the inner laminate. Accordingly, lithium ions eluted in the electrolyte during pre-doping enter each negative electrode unit constituting the inner laminate from the side surface side of the inner laminate. Since the end of each laminated negative electrode unit is desired on the side surface of the inner laminate, lithium ions in the electrolytic solution can easily enter from the end of each negative electrode unit to the surface of each negative electrode unit. For this reason, it is possible to uniformly dope lithium ions into the negative electrode active material of each negative electrode current collecting unit and the outer negative electrode unit without forming fine holes in each negative electrode current collector (that is, without increasing the current collecting resistance). it can. Further, since metallic lithium is only provided on the outer negative electrode current collector, workability is improved as compared with the case where metallic lithium is provided on all negative electrode current collectors. Therefore, it is possible to uniformly dope lithium ions into the negative electrode active material on the stacked negative electrode units without increasing the current collecting resistance and the work man-hours.

  In the present invention, the term “flat plate” means a shape in which two surfaces having a small thickness and facing in opposite directions are formed. For example, a sheet shape is also included in the flat plate shape of the present invention. The “both end surfaces” of the inner laminate means surfaces on both ends in the stacking direction of the negative electrode unit and the positive electrode unit constituting the inner laminate, and “side surfaces” of the inner laminate mean the negative electrode unit and the positive electrode. It means the surface along the stacking direction of the unit.

  Therefore, when the inner laminate is a rectangular parallelepiped, the inner laminate is formed by two end faces (both end faces) in the stacking direction and four side faces along the stacking direction. In the case where the inner laminated body has a rectangular parallelepiped shape, in the present invention, metallic lithium provided on the outer negative electrode current collector is opposed to at least one of the four side surfaces. In this case, metallic lithium may be disposed facing one side surface, metallic lithium may be disposed facing two side surfaces, or metallic lithium may be disposed facing three side surfaces. However, since a lead portion for taking out electric energy is provided on one side surface of the inner laminated body, it is preferable that metallic lithium is disposed facing the side surface other than the side surface where the lead portion is provided.

  The separator may comprise an internal separator and a side separator. In this case, in the first step, the negative electrode unit and the positive electrode unit are alternately stacked with the inner separator interposed therebetween, and the side separator is formed between the negative electrode unit and the positive electrode unit so that the side separator forms a side surface of the inner stacked body. The step may be a step of forming an internal laminated body by being arranged along the laminating direction. Further, the second step is to cover the inner laminate with the outer negative electrode unit so that the outer negative electrode active material of the outer negative electrode unit faces both end faces of the inner laminate and the metallic lithium faces the side separator. The step of forming the power storage unit is preferable. According to this, the metal ion eluted in electrolyte solution passes a side part separator, and approachs the surface of each negative electrode unit from the edge part of each laminated | stacked negative electrode unit.

  Also, the inner separator is preferably connected to the side separator. More specifically, the internal separator may be connected to the side separator so that a gap between one end portions of two adjacent internal separators is closed by the side separator. According to this, one end of the negative electrode unit or the positive electrode unit disposed between two adjacent internal separators is covered with the side separator, so that these end portions are exposed from the side surface of the internal laminate. It is prevented. This prevents the positive electrode unit and the negative electrode unit from being curved and partially exposed from the side surface of the inner laminate when the outer laminate unit covers the inner laminate. As a result, it is possible to reliably prevent the partially exposed portion from contacting and the short circuit between the positive electrode unit and the negative electrode unit.

  The separator preferably further includes a pair of end separators. In this case, in the first step, the negative electrode unit and the positive electrode unit are alternately stacked with the inner separator interposed therebetween, and a pair of end separators are disposed on both end surfaces of the inner stacked body, and the side separator is the inner stacked body. The side separator is disposed along the stacking direction of the negative electrode unit and the positive electrode unit so as to form the side surface of the negative electrode unit and the positive electrode unit, thereby forming the inner laminate, and the second step is the outer negative electrode active of the outer negative electrode unit. It is preferable that the storage unit be formed by covering the inner laminate with the outer negative electrode unit so that the substance faces the end separator and the metallic lithium faces the side separator.

  The present invention also provides a negative electrode unit having a flat negative electrode current collector and a negative electrode active material provided on both surfaces of the negative electrode current collector, and a flat positive electrode current collector and a positive electrode current collector on both surfaces. A positive electrode unit having a positive electrode active material and a separator, and an internal laminate formed by alternately laminating negative electrode units and positive electrode units across the separator, a first portion, a second portion, and a second portion A plate-like outer negative electrode current collector formed so that three portions are connected in this order, and an outer negative electrode active material provided on one surface of the first portion and the second portion and pre-doped with lithium ions, A power storage unit comprising an outer negative electrode unit that covers the inner stacked body so that the negative electrode active material faces both end faces of the inner stacked body and the second portion faces the side surface of the inner stacked body; Case to store If, to provide a power storage device and an electrolytic solution filled in the case.

  In this case, the separator includes an internal separator and a side separator, and the negative electrode unit and the positive electrode unit are alternately stacked with the internal separator interposed therebetween, and the side separator is internally laminated so as to form a side surface of the internal laminate. It is good to arrange | position along the lamination direction of a body, and the 2nd part is good to be arrange | positioned facing a side part separator. The separator further includes an end separator, and the end separator is disposed on both end faces of the inner laminate, and the outer negative electrode active material provided in the first part and the second part faces the end separator. It is good to be arranged.

  According to the present invention, it is possible to provide an electricity storage device in which lithium ions are pre-doped uniformly on a negative electrode active material without increasing current collection resistance and work man-hours.

It is a schematic sectional drawing which shows the lithium ion capacitor as an electrical storage device. It is II-II sectional drawing of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is IV-IV sectional drawing of FIG. It is a figure which shows the inner laminated body of FIG. It is a figure which shows a negative electrode unit. It is a figure which shows a positive electrode unit. It is a figure which expand | deploys and shows the outer side negative electrode unit which concerns on 1st Embodiment. It is sectional drawing which shows the electrical storage unit before the pre dope formed at the 2nd process of 1st Embodiment. It is sectional drawing which shows the lithium ion capacitor which the 4th process of 1st Embodiment was completed. It is sectional drawing which cut | disconnected the electrical storage unit which concerns on 2nd Embodiment in the cross section perpendicular | vertical to a height direction. It is a figure which shows the internal laminated body of FIG. It is a figure which expand | deploys and shows the outer side negative electrode unit which concerns on 2nd Embodiment. It is sectional drawing which shows the electrical storage unit before the pre dope formed at the 2nd process of 2nd Embodiment. It is sectional drawing which shows the lithium ion capacitor which the 4th process of 2nd Embodiment was completed. It is sectional drawing which cut | disconnected the electrical storage unit which concerns on 3rd Embodiment in the cross section perpendicular | vertical to a height direction. It is a figure which shows the internal laminated body of FIG. It is XVIII-XVIII sectional drawing of FIG. It is a figure which expand | deploys and shows the outer side negative electrode unit which concerns on 3rd Embodiment. It is sectional drawing which shows the lithium ion capacitor which the 4th process of 3rd Embodiment was completed. It is sectional drawing which shows the lithium ion capacitor which the 4th process of 3rd Embodiment was completed.

(First embodiment)
The first embodiment of the present invention will be described below. FIG. 1 is a schematic cross-sectional view showing a lithium ion capacitor as an electricity storage device according to the present embodiment. As shown in FIG. 1, a lithium ion capacitor 1 according to the present embodiment includes a bag-like case 6, a nonaqueous electrolytic solution 5 filled in the case 6, and a power storage unit immersed in the nonaqueous electrolytic solution 5. 2 is provided. In the following description, when each configuration is described with a direction, the vertical direction in FIG. 1 is defined as the height direction, and the horizontal direction is defined as the width direction. Further, a direction perpendicular to the paper surface of FIG. 1, that is, a direction perpendicular to the height direction and the width direction is defined as the front-rear direction.

  The case 6 is configured so that the nonaqueous electrolytic solution 5 and the power storage unit 2 can be hermetically accommodated. The case 6 is an aluminum soft case in this embodiment. The case 6 is formed into a rectangular bag shape by stacking two rectangular laminate films made of aluminum and joining the four sides to each other by welding. A positive terminal 61 and a negative terminal 62 are attached to the case 6. The positive electrode terminal 61 and the negative electrode terminal 62 are attached to the case 6 so that the tip portion protrudes from the case 6 while maintaining the sealed state in the case 6. The power storage unit 2 in the case 6 is electrically connected to the base end sides of the terminals 61 and 62. Therefore, by connecting an electric load between the positive electrode terminal 61 and the negative electrode terminal 62, the electric energy generated in the power storage unit 2 is taken out.

  The non-aqueous electrolyte 5 is a non-aqueous solution having electrical conductivity, and is generated, for example, by dissolving a lithium salt electrolyte in an organic solvent. For example, LiPF6 is used as the lithium salt electrolyte, but not limited thereto. For example, ethylene carbonate (EC) or diethyl carbonate (DEC) is used as the organic solvent, but not limited thereto.

  2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is a sectional view taken along line III-III in FIG. 1, and FIG. 4 is a sectional view taken along line IV-IV in FIG. 2 and 3 are cross-sectional views of the lithium ion capacitor 1 cut along a plane perpendicular to the width direction, and FIG. 4 is a cross-sectional view of the lithium ion capacitor 1 cut along a plane perpendicular to the height direction. is there. As shown in FIGS. 2 to 4, the power storage unit 2 includes an inner laminated body 3 and an outer negative electrode unit 4.

  FIG. 5 is a cross-sectional view showing only the inner laminate 3 shown in FIG. As shown in FIG. 5, the inner laminate 3 includes a plurality of negative electrode units 31, a plurality of positive electrode units 32, and a separator 33. A plurality of negative electrode units 31 and a plurality of positive electrode units 32 are stacked along the front-rear direction with the separator 33 interposed therebetween. In the present embodiment, the inner laminate 3 has a rectangular parallelepiped shape. Therefore, the inner laminated body 3 is formed by both side surfaces of the negative electrode unit 31 and the positive electrode unit 32 in the stacking direction (front-rear direction) and four side surfaces formed along the stacking direction.

  6A and 6B are views showing the negative electrode unit 31. FIG. 6A is a front view of the negative electrode unit 31 viewed from the front-rear direction, and FIG. 6B is a side view of the negative electrode unit 31 viewed from the width direction. As shown in FIG. 6, the negative electrode unit 31 includes a sheet-like negative electrode current collector 311 and a negative electrode active material 312. The negative electrode current collector 311 has a substantially rectangular shape when viewed from the front. A negative electrode lead portion A is formed on the negative electrode current collector 311 so as to protrude from the upper left portion when viewed from the front. The negative electrode current collector 311 is formed of a material having good conductivity. For example, in this embodiment, a copper foil is used as the negative electrode current collector 311. The negative electrode active material 312 is applied to both surfaces of the negative electrode current collector 311. The negative electrode active material 312 is not applied to the negative electrode lead portion A. The negative electrode active material 312 is made of a material that can occlude and release lithium ions. The negative electrode active material 312 may be made of, for example, graphite, hard carbon, soft carbon, CNT (carbon nanotube), or the like, but is not limited to this as long as the material can perform the above-described function.

  7A and 7B are diagrams showing the positive electrode unit 32. FIG. 7A is a front view of the positive electrode unit 32 viewed from the front-rear direction, and FIG. 7B is a side view of the positive electrode unit 32 viewed from the width direction. As shown in FIG. 7, the positive electrode unit 32 includes a sheet-like positive electrode current collector 321 and a positive electrode active material 322. The positive electrode current collector 321 has a substantially rectangular shape when viewed from the front. A positive electrode lead portion B is formed on the positive electrode current collector 321 so as to protrude from the upper right portion when viewed from the front. The positive electrode current collector 321 is formed of a material having good conductivity. For example, in this embodiment, an aluminum foil is used as the positive electrode current collector 321. The positive electrode active material 322 is applied to both surfaces of the positive electrode current collector 321. The positive electrode active material 322 is not applied to the positive electrode lead portion B. The positive electrode active material 322 is made of a material that can reversibly carry lithium ions or electrolyte anions. The positive electrode active material 322 may be composed of, for example, activated carbon, but is not limited to this as long as the material can perform the above-described function.

  As shown in FIG. 5, the separator 33 of the inner laminate 3 includes a plurality of inner separators 331, a pair of end separators 332, and one side separator 333. The negative electrode unit 31 and the positive electrode unit 32 are alternately stacked along the front-rear direction with a plurality of internal separators 331 interposed therebetween, and a pair of end separators 332, 332 are provided on both end surfaces of the inner stacked body 3 in the stacking direction (front-rear direction). Arranged. Further, the side separator 333 is disposed along the stacking direction so as to form a part of the side surface of the inner laminate 3 (the left side surface in FIG. 5).

  Further, as shown in FIG. 5, the left end portions in the width direction of all the internal separators 331 and the pair of end separators 332 are connected to the side separator 333. Specifically, a gap formed at the left end of each of the adjacent end separator 332 and the internal separator 331 and a gap formed at the left end of each of the two adjacent internal separators 331 and 331 are All the internal separators 331 and the pair of end separators 332 are connected to the side separators 333 so as to be closed by the side separators 333. Therefore, a space in which one end (left end in FIG. 5) is closed by the side separator 333 is formed in the separator 33 along the stacking direction (front-rear direction). The negative electrode unit 31 or the positive electrode unit 32 is disposed in each space. The positive electrode unit 32 is disposed in a space between the end separator 332 and the internal separator 331 adjacent thereto, that is, a space located at both ends in the stacking direction.

  The separator 33 is provided to prevent contact between the negative electrode unit 31 and the positive electrode unit 32. A porous substrate is preferably used as the separator 33. As the separator 33, for example, a porous film base material such as polyethylene or polypropylene can be adopted, but it is not limited as long as it fulfills the above function.

  As shown in FIG. 4, the outer negative electrode unit 4 is provided so as to wrap the inner laminate 3. FIG. 8 is a developed view of the outer negative electrode unit 4 enclosing the inner laminate 3, FIG. 8 (a) is a front view, and FIG. 8 (b) is a side view. As shown in FIG. 8, the outer negative electrode unit 4 includes a sheet-like outer negative electrode current collector 41 and an outer negative electrode active material 42. The outer negative electrode current collector 41 has a horizontally long rectangular shape in which a rectangular first portion 41a, a second portion 41b, and a third portion 41c are connected in the horizontal direction in this order. A negative electrode lead portion A is formed in the upper left portion of the first portion 41a and the upper right portion of the third portion 41c. The first portion 41 a and the third portion 41 c have the same size and shape as the negative electrode current collector 311 of the negative electrode unit 31. The outer negative electrode current collector 41 is preferably formed of the same material as the negative electrode current collector 311, but is not limited to this as long as it is formed of a material having good conductivity.

  The outer negative electrode active material 42 is applied to one surface of the first portion 41a and the third portion 41c facing the same side. The outer negative electrode active material 42 may be the same material as the negative electrode active material 312 applied to the negative electrode current collector 311, but may be a different material. On the other hand, the outer negative electrode active material 42 is not applied to the other surface of the first portion 41a and the third portion 41c facing the same side, the second portion 41b, and the negative electrode lead portions A and A. Further, in the second portion 41b, the surface facing the same side as the one surface (the surface coated with the outer negative electrode active material 42) of the first portion 41a and the third portion 41c (the blackened portion in FIG. 8) ) Is affixed with metal lithium 43 used in manufacturing the lithium ion capacitor 1. Since the metallic lithium 43 is eluted as ions in the non-aqueous electrolyte 5 in the manufacturing process of the lithium ion capacitor 1, it is already lost when the manufacturing of the lithium ion capacitor 1 is completed, strictly, when the pre-doping is completed. Yes.

  As shown in FIG. 4, the outer negative electrode unit 4 faces both end faces of the inner laminate 3 in the stacking direction (front-rear direction) of the negative electrode unit 31 and the positive electrode unit 32 and the left side surface of the inner laminate 3 in the width direction. Thus, the inner laminated body 3 is covered. In this case, the outer negative electrode active material 42 applied to the first portion 41 a of the outer negative electrode current collector 41 is in face-to-face contact with the end separator 332 disposed on the front end surface of the inner laminate 3. Further, the outer negative electrode active material 42 applied to the third portion 41 c of the outer negative electrode current collector 41 is brought into face contact with the end separator 332 disposed on the rear end surface of the inner laminate 3. Further, the second portion 41 b of the outer negative electrode current collector 41 is disposed facing the side separator 333 provided on the left side surface in the width direction of the inner laminate 3.

  The negative electrode lead part A provided on the negative electrode current collector 311 of each negative electrode unit 31 of the inner laminate 3 and the two negative electrode lead parts A provided on the outer negative electrode current collector 41 of the outer negative electrode unit 4 are shown in FIG. As shown, it is connected by a negative electrode side conductive connection member 25 such as a lead wire. The negative electrode side conductive connection member 25 is electrically connected to the negative electrode terminal 62. Moreover, the positive electrode lead part B provided in the positive electrode current collector 321 of each positive electrode unit 32 of the inner laminate 3 is connected by a positive electrode side conductive connection member 26 such as a lead wire as shown in FIG. The positive electrode side conductive connection member 26 is electrically connected to the positive electrode terminal 61. Note that the negative electrode lead portion A may be configured to be connected to the negative electrode terminal 62 by bonding, rivet fastening, or the like without using the negative electrode side conductive connection member 25. Similarly, the positive electrode lead portion B may be configured to be connected to the positive electrode terminal 61 by bonding, rivet fastening, or the like without using the positive electrode side conductive connection member 26.

  Lithium ions are occluded (pre-doped) in advance in the negative electrode active material 312 of each negative electrode unit 31 and the outer negative electrode active material 42 of the outer negative electrode unit 4.

  In the lithium ion capacitor 1 having such a configuration, the negative electrode unit 31 and the outer negative electrode unit 4 charge and discharge electric energy by an electrochemical reaction of lithium ions, and the positive electrode unit 32 stores lithium ions or anions. Electric energy is charged and discharged by physical adsorption and desorption.

  Next, a method for manufacturing the lithium ion capacitor 1 having such a configuration will be described.

(First step)
First, the inner laminated body 3 as shown in FIG. 5 is formed. That is, the negative electrode unit 31 and the positive electrode unit 32 are alternately stacked with the internal separator 331 interposed therebetween. A pair of end separators 332 and 332 are disposed on both end faces of the laminate of the negative electrode unit 31 and the positive electrode unit 32. Furthermore, the side separator 333 is disposed along the stacking direction so that the side separator 333 forms the left side surface of the inner laminate 3 in FIG. In this way, the internal laminate 3 is formed in which the pair of end separators 332 and 332 are arranged on both end surfaces in the laminating direction and the side separator 333 is arranged on the left side surface.

(Second step)
Next, the outer negative electrode current collector 41 is prepared. Then, the outer negative electrode active material 42 is applied to one surface of the first portion 41a and the third portion 41c of the prepared outer negative electrode current collector 41, and the metal lithium 43 is attached to one surface of the second portion 41b. Thus, the outer negative electrode unit 4 is formed. In this case, the metal lithium 43 may be pressure-bonded to the second portion 41b so that the metal lithium 43 reliably contacts the second portion 41b of the outer negative electrode current collector 41.

  Next, the inner laminate 3 is covered with the outer negative electrode unit 4. In this case, the first separator 41 a of the outer negative electrode current collector 41 is applied to the end separator 332 disposed on the front end surface in the stacking direction (front-rear direction) of the negative electrode unit 31 and the positive electrode unit 32 in the inner stacked body 3. The outer negative electrode active material 42 applied to the third portion 41c of the outer negative electrode current collector 41 faces the end separator 332 disposed on the rear end surface in the stacking direction. Then, the inner laminate 3 is placed on the outer side so that the metal separator 43 pressed against the second portion 41 b of the outer negative electrode current collector 41 faces the side separator 333 disposed on one side of the inner laminate 3. Covered with the negative electrode current collector 41. Thereby, the power storage unit 2 before pre-doping is formed. FIG. 9 is a diagram showing the power storage unit 2 before pre-doping formed in the second step. Here, as shown in FIG. 9, the metallic lithium 43 provided in the second portion 41 b of the outer negative electrode current collector 41 is stacked in the stacking direction (front-rear direction) of the negative electrode unit 31 and the positive electrode unit 32 in the inner stacked body 3. Are arranged facing the side separator 333 over the entire area.

(Third step)
Next, the negative electrode current collector 311 and the negative electrode lead portion A of the outer negative electrode current collector 41 are connected by the negative electrode side conductive connection member 25, so that all the negative electrode current collectors 311 and the outer negative electrode current collectors in the power storage unit 2 are connected. The electric body 41 is electrically connected. In addition, by connecting the positive electrode lead portion B of the positive electrode current collector 321 with the positive electrode side conductive connection member 26, all the positive electrode current collectors 321 in the power storage unit 2 are electrically connected.

  Subsequently, two rectangular aluminum laminate films were prepared, these were overlaid, and 3 sides of the 4 sides of each of the overlaid laminate films were sealed by welding to open one side. The formed bag-like case 6 is formed. The power storage unit 2 is put into the case 6 from the opening of the case 6. Then, the negative electrode side conductive connection member 25 is connected to the negative electrode terminal 62, and the positive electrode side conductive connection member 26 is connected to the positive electrode terminal 61.

(4th process)
Thereafter, the nonaqueous electrolytic solution 5 is filled in the case 6. After filling, the positive electrode terminal 61 and the negative electrode terminal 62 are sandwiched in the opening of the case 6, and the opening portion is sealed by welding in that state. FIG. 10 shows the lithium ion capacitor 1 in which the fourth step is completed.

  By filling the case 6 with the non-aqueous electrolyte 5 in the fourth step, the power storage unit 2 is immersed in the non-aqueous electrolyte 5. Thereby, the metal lithium 43 attached to the second portion 41 b of the outer negative electrode current collector 41 of the power storage unit 2 is also immersed in the non-aqueous electrolyte 5. The metallic lithium 43 is short-circuited to each negative electrode current collector 311 via the outer negative electrode current collector 41 and the negative electrode side conductive connecting member 25. Therefore, the metal lithium 43 emits electrons to the outer negative electrode current collector 41 and each negative electrode current collector 311 and is eluted as lithium ions in the non-aqueous electrolyte 5.

  The lithium ions eluted in the non-aqueous electrolyte 5 migrate on the surface of the outer negative electrode unit 4 in the power storage unit 2 along the width direction, and pass through the side separator 333 to pass through the surface of each negative electrode unit 31. Run along the width direction. Then, lithium ions are occluded in the outer negative electrode active material 42 of the outer negative electrode unit 4 and the negative electrode active material 312 of each negative electrode unit 31. Thus, pre-doping is completed. When the pre-doping is completed, the metallic lithium 43 provided in the outer negative electrode unit 4 disappears as shown in FIG.

  Thus, according to the present embodiment, the metal lithium 43 attached to the outer negative electrode current collector 41 faces the side surface of the inner laminate 3. Therefore, lithium ions eluted in the non-aqueous electrolyte 5 enter the inner laminate 3 from the side surface. The end of each negative electrode unit 31 is desired on the side surface of the inner laminate 3. Accordingly, lithium ions can easily enter the respective negative electrode units 31 from the end portions of the respective negative electrode units 31 and migrate along the surfaces of the respective negative electrode units 31. Therefore, the negative electrode active material 312 provided in all the negative electrode units 31 and the outer negative electrode active provided in the outer negative electrode unit 4 can be uniformly pre-doped with lithium ions. Furthermore, according to the present embodiment, as shown in FIG. 9, in the second step, the metal lithium 43 extends over the entire area in the stacking direction (front-rear direction) of the negative electrode unit 31 and the positive electrode unit 32 in the inner stacked body 3. The inner laminate 3 is covered with the outer negative electrode unit 4 so as to face the side separator 333. That is, the metal lithium 43 faces the end portions of all the negative electrode units 31 of the inner laminate 3 with the side separator 333 interposed therebetween. For this reason, the lithium ions eluted in the non-aqueous electrolyte 5 can uniformly enter all the negative electrode units 31, and the negative electrode active materials 312 of all the negative electrode units 31 can be evenly doped with lithium ions.

  Further, as shown in FIG. 5, the left ends in the width direction of all the internal separators 331 and the end separators 332 are connected to the side separators 333. For this reason, the gap between the left ends of the adjacent internal separators 331 or the gap between the adjacent end separator 332 and the left end of the internal separator 331 is closed by the side separator 333. Therefore, the left end portion (the end portion on the side covered with the outer negative electrode unit 4) of the negative electrode unit 31 or the positive electrode unit 32 disposed between two adjacent separators is covered with the side separator 333. The end portion is prevented from being exposed from the side surface of the inner laminate 3. As a result, when covering the inner laminated body 3 with the outer negative electrode unit 4, the negative electrode unit 31 and the positive electrode unit 32 are prevented from being curved and their end portions are partially exposed from the side surface of the inner laminated body 3. Therefore, it can prevent reliably that the part exposed partially contacts and the negative electrode unit 31 and the positive electrode unit 32 are short-circuited.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. The overall configuration of the lithium ion capacitor as the electricity storage device according to the present embodiment is the same as the configuration illustrated in FIG. 1 described in the first embodiment. Therefore, the lithium ion capacitor according to the present embodiment also includes the power storage unit 2, the nonaqueous electrolytic solution 5, and the case 6.

  FIG. 11 is a cross-sectional view of the power storage unit 2 according to the present embodiment cut along a cross section perpendicular to the height direction. As shown in FIG. 11, the power storage unit 2 according to this embodiment includes an inner stacked body 3 ′ and an outer negative electrode unit 4 ′. The inner laminate 3 ′ is covered by the outer negative electrode unit 4 ′.

  FIG. 12 is a diagram showing the inner laminated body 3 ′ of the power storage unit 2 shown in FIG. 11. As shown in FIG. 12, the inner laminate 3 ′ includes a plurality of negative electrode units 31, a plurality of positive electrode units 32, and a separator 33 ′. A plurality of negative electrode units 31 and a plurality of positive electrode units 32 are stacked along the front-rear direction with the separator 33 'interposed therebetween. The inner laminated body 3 ′ according to the present embodiment has a rectangular parallelepiped shape, and is formed by both end surfaces of the negative electrode unit 31 and the positive electrode unit 32 in the stacking direction (front-rear direction) and four side surfaces along the stacking direction. Since the structure of the negative electrode unit 31 and the structure of the positive electrode unit 32 are the same as the structure of the negative electrode unit 31 and the structure of the positive electrode unit 32 which were demonstrated in the said 1st Embodiment, the description is abbreviate | omitted.

  The separator 33 ′ of the inner laminate 3 ′ includes a plurality of inner separators 331 ′, a pair of end separators 332 ′, and a pair of side separators (left side separator 333 </ b> L, right side separator 333 </ b> R). The negative electrode unit 31 and the positive electrode unit 32 are alternately stacked along the front-rear direction with a plurality of internal separators 331 ′ interposed therebetween, and a pair of end separators 332 ′, 332 ′ are disposed at both ends in the stacking direction (front-rear direction). The Further, the left side separator 333L is disposed along the stacking direction so as to form the left side surface of FIG. 12 among the four side surfaces of the inner laminated body 3 ′, and the right side separator 333R is disposed on the four side surfaces of the inner laminated body 3 ′. Of these, they are arranged along the stacking direction so as to form the right side surface of FIG. The left end in the width direction of all the internal separators 331 and end separators 332 is connected to the left separator 333L. Therefore, as shown in FIG. 12, spaces in which one end is closed by the left separator 333L are formed in the separator 33 ′ along the stacking direction (front-rear direction), and the negative electrode units 31 are respectively formed in the spaces. Alternatively, the positive electrode unit 32 is provided. The positive electrode unit 32 is disposed in a space between the end separator 332 'and the adjacent internal separator 331', that is, a space located at both ends in the stacking direction. Further, the right end in the width direction of all the internal separators 331 ′ and end separators 332 ′ may be connected to the right separator 333R, but it is difficult to form the internal laminate 3 ′. In some cases, it may not be connected.

  As shown in FIG. 11, an outer negative electrode unit 4 'is provided so as to enclose the inner laminate 3'. FIG. 13 is a developed view of the outer negative electrode unit 4 ′, FIG. 13A is a front view, and FIG. 13B is a side view. As shown in FIG. 13, the outer negative electrode unit 4 ′ according to this embodiment includes a sheet-like outer negative electrode current collector 41 ′ and an outer negative electrode active material 42. The outer negative electrode current collector 41 ′ has a horizontally long rectangular shape in which a rectangular first portion 41 a, second portion 41 b, third portion 41 c, and fourth portion 41 d are connected in this order in the horizontal direction of FIG. 13. A negative electrode lead portion A is formed in the upper left portion of the first portion 41a and the upper right portion of the third portion 41c. The first portion 41a and the third portion 41c have the same size and shape as the negative electrode current collector 311 of the negative electrode unit 31 (see FIG. 5).

  The outer negative electrode active material 42 is applied to one surface of the first portion 41a and the third portion 41c facing the same side. On the other hand, the outer negative active material 42 is not applied to the other surface of the first portion 41a and the third portion 41c facing the same side, the second portion 41b, the fourth portion 41d, and the negative electrode lead portions A and A. . Of the second portion 41b and the fourth portion 41d, the surface facing the same side as the one surface (the surface coated with the outer negative electrode active material 42) of the first portion 41a and the third portion 41c (blacked in FIG. 13). The metal lithium 43 used at the time of manufacturing the lithium ion capacitor 1 is attached to the portion). Since the metallic lithium 43 is eluted as ions in the non-aqueous electrolyte 5 in the manufacturing process of the lithium ion capacitor 1, it is already lost when the manufacturing of the lithium ion capacitor 1 is completed, strictly, when the pre-doping is completed. Yes.

  As shown in FIG. 11, the outer negative electrode unit 4 ′ faces both end faces of the inner laminate 3 ′ in the stacking direction (front-rear direction) of the negative electrode unit 31 and the positive electrode unit 32 and the left and right side surfaces in the width direction. Cover the inner laminate 3 '. In this case, the outer negative electrode active material 42 applied to the first portion 41a of the outer negative electrode current collector 41 'is brought into face contact with the end separator 332' disposed on the front end surface of the inner multilayer body 3 '. In addition, the outer negative electrode active material 42 applied to the third portion 41c of the outer negative electrode current collector 41 'is in contact with the end separator 332 disposed on the rear end surface of the inner laminate 3'. Further, the second portion 41b of the outer negative electrode current collector 41 ′ is disposed to face the left side separator 333L provided on the left side surface in the width direction of the inner laminated body 3 ′, and the fourth portion of the outer negative electrode current collector 41 ′. The portion 41d is disposed so as to face the right side separator 333R provided on the right side surface in the width direction of the inner laminated body 3 ′.

  Since other configurations are the same as those in the first embodiment, description thereof will be omitted.

  Next, a method for manufacturing a lithium ion capacitor according to this embodiment will be described.

(First step)
First, an inner laminate 3 ′ as shown in FIG. 12 is formed. That is, the negative electrode unit 31 and the positive electrode unit 32 are alternately stacked with the internal separator 331 ′ interposed therebetween. In addition, a pair of end separators 332 ′ and 332 ′ are disposed on both end surfaces of the laminate of the negative electrode unit 31 and the positive electrode unit 32. Further, the left side separator 333L is disposed along the stacking direction so that the left side separator 333L forms the left side surface in FIG. 12 of the inner laminated body 3 ′, and the right side separator 333R is the inner laminated body 3 ′ of FIG. The right side separator 333R is disposed along the stacking direction so as to form the right side. In this way, the internal laminate 3 is formed in which the pair of end separators 332 and 332 are disposed on both end surfaces in the stacking direction, the left separator 333L is disposed on the left side, and the right separator 333R is disposed on the right side. Is done.

(Second step)
Next, an outer negative electrode current collector 41 ′ is prepared. Then, the outer negative electrode active material 42 is applied to one surface of the first portion 41a and the third portion 41c of the prepared outer negative electrode current collector 41 ′, and metal is applied to one surface of the second portion 41b and the fourth portion 41d. By attaching lithium 43, the outer negative electrode unit 4 ′ is formed. In this case, when the metal lithium 43 is bonded to the second portion 41b and the fourth portion 41d so that the metal lithium 43 is surely in contact with the second portion 41b and the fourth portion 41d of the outer negative electrode current collector 41 ′. Good.

  Next, the inner laminate 3 ′ is covered with the outer negative electrode unit 4 ′. In this case, the first portion 41a of the outer negative electrode current collector 41 ′ is connected to the end separator 332 ′ disposed on the front end surface in the stacking direction (front-rear direction) of the negative electrode unit 31 and the positive electrode unit 32 in the inner stacked body 3 ′. The outer negative electrode is coated on the third portion 41c of the outer negative electrode current collector 41 ′ on the end separator 332 ′ disposed on the rear end surface in the stacking direction. The active material 42 faces, the metallic lithium 43 pressed against the second portion 41b of the outer negative electrode current collector 41 ′ faces the left separator 333L disposed on the left side of the inner laminate 3 ′, and the inner The inner laminate 3 ′ is placed on the outer negative electrode so that the metal separator 43 pressed against the fourth portion 41 d of the outer negative electrode current collector 41 ′ faces the right side separator 333 R disposed on the right side of the laminate 3. Yu Covered by Tsu door 4 '. Thereby, the power storage unit 2 before pre-doping is formed. FIG. 14 is a diagram showing the power storage unit 2 before pre-doping formed in the second step. Here, as shown in FIG. 14, the metal lithium 43 provided in the second portion 41 b and the fourth portion 41 d of the outer negative electrode current collector 41 ′ is connected to the negative electrode unit 31 and the positive electrode unit 32 in the inner laminate 3. The side separator 333 (the left side separator 333L and the right side separator 333R) is disposed facing the entire region in the stacking direction (front-rear direction).

(Third step)
Next, by connecting the negative electrode lead part A of the negative electrode current collector 311 and the outer negative electrode current collector 41 ′ with the negative electrode side conductive connecting member 25, all the negative electrode current collectors 311 and the outer negative electrode in the power storage unit 2 are connected. The current collector 41 ′ is electrically connected. In addition, by connecting the positive electrode lead portion B of the positive electrode current collector 321 with the positive electrode side conductive connection member 26, all the positive electrode current collectors 321 in the power storage unit 2 are electrically connected. Then, the power storage unit 2 is placed in the case 6, the negative electrode side conductive connection member 25 is connected to the negative electrode terminal 62, and the positive electrode side conductive connection member 26 is connected to the positive electrode terminal 61.

(4th process)
Thereafter, the nonaqueous electrolytic solution 5 is filled in the case 6. After filling, the positive electrode terminal 61 and the negative electrode terminal 62 are sandwiched in the opening of the case 6, and the opening portion is sealed by welding in that state. FIG. 15 shows the lithium ion capacitor in which the fourth step is completed.

  By filling the case 6 with the non-aqueous electrolyte 5 in the fourth step, the power storage unit 2 is immersed in the non-aqueous electrolyte 5. As a result, the metal lithium 43 attached to the second portion 41 b and the fourth portion 41 d of the outer negative electrode current collector 41 ′ of the power storage unit 2 is also immersed in the non-aqueous electrolyte 5. The metallic lithium 43 is short-circuited to each negative electrode current collector 311 via the outer negative electrode current collector 41 ′ and the negative electrode side conductive connecting member 25. Therefore, the metal lithium 43 emits electrons to the outer negative electrode current collector 41 ′ and the respective negative electrode current collectors 311, and is eluted as lithium ions in the nonaqueous electrolytic solution 5.

  Lithium ions eluted into the non-aqueous electrolyte 5 from the metal lithium 43 provided in the second portion 41b of the outer negative electrode current collector 41 ′ are transferred to the outer negative electrode unit 4 ′ in the power storage unit 2 along the width direction. While migrating the surface, the surface of each negative electrode unit 31 is migrated along the width direction through the left separator 333L. Then, lithium ions are occluded in the outer negative electrode active material 42 of the outer negative electrode unit 4 ′ and the negative electrode active material 312 of each negative electrode unit 31. Further, the lithium ions eluted into the non-aqueous electrolyte 5 from the metal lithium 43 provided in the fourth portion 41d of the outer negative electrode current collector 41 ′ are removed from the outer negative electrode unit 4 in the power storage unit 2 along the width direction. And the surface of each negative electrode unit 31 is migrated along the width direction through the right separator 333R. Then, lithium ions are occluded in the outer negative electrode active material 42 of the outer negative electrode unit 4 ′ and the negative electrode active material 312 of each negative electrode unit 31. Thus, pre-doping is completed. When the pre-doping is completed, the metal lithium 43 provided in the outer negative electrode unit 4 disappears.

  As described above, according to the present embodiment, the metal lithium 43 attached to the outer negative electrode current collector 41 ′ faces two opposing side surfaces of the inner stacked body 3 ′. Therefore, lithium ions eluted in the non-aqueous electrolyte 5 enter the inner laminated body 3 ′ from two opposing side surfaces. The end of each negative electrode unit 31 is desired on the side surface of the inner laminate 3 '. Accordingly, lithium ions can easily enter the respective negative electrode units 31 from the end portions of the respective negative electrode units 31 and migrate along the surfaces of the respective negative electrode units 31. Therefore, the negative electrode active material 312 provided in all the negative electrode units 31 and the outer negative electrode active material 42 provided in the outer negative electrode unit 4 ′ can be uniformly predoped with lithium ions. Furthermore, according to the present embodiment, as shown in FIG. 14, in the second step, the metallic lithium 43 provided in the outer negative electrode unit 4 ′ is replaced by the negative electrode unit 31 and the positive electrode unit 32 in the inner laminate 3 ′. The inner laminated body 3 ′ is covered with the outer negative electrode unit 4 ′ so as to face the left side separator 333L and the right side separator 333R over the entire area in the laminating direction (front-rear direction). That is, the metal lithium 43 faces the end portions of all the negative electrode units 31 of the inner stacked body 3 ′ with the side separator interposed therebetween. For this reason, the lithium ions eluted in the non-aqueous electrolyte 5 can uniformly enter all the negative electrode units 31, and the negative electrode active materials 312 of all the negative electrode units 31 can be evenly doped with lithium ions.

  In addition, according to the present embodiment, since lithium ions in the non-aqueous electrolyte 5 enter from two directions facing each negative electrode unit 31, pre-doping progresses efficiently, pre-doping time can be shortened, The entire region in the negative electrode active material 312 on the negative electrode current collector 311 can be uniformly pre-doped with lithium ions.

(Third embodiment)
Next, a third embodiment of the present invention will be described. The overall configuration of the lithium ion capacitor as the electricity storage device according to this embodiment is also the same as the configuration shown in FIG. 1 described in the first embodiment. Therefore, the lithium ion capacitor according to the present embodiment also includes the power storage unit 2, the nonaqueous electrolytic solution 5, and the case 6.

  FIG. 16 is a cross-sectional view of the power storage unit 2 according to the present embodiment cut along a cross section perpendicular to the height direction. As shown in FIG. 16, the power storage unit 2 according to the present embodiment includes an inner laminated body 3 ″ and an outer negative electrode unit 4 ″. The inner laminate 3 ″ is covered by the outer negative electrode unit 4 ″.

  FIG. 17 is a diagram showing the inner laminate 3 ″ of the power storage unit 2 shown in FIG. 16. As shown in FIG. 16, the inner laminate 3 ″ includes a plurality of negative electrode units 31, a plurality of positive electrode units 32, and Separator 33 ″. The plurality of negative electrode units 31 and the plurality of positive electrode units 32 are stacked along the front-rear direction with the separator 33 ″ interposed therebetween. The inner laminated body 3 ″ has a rectangular parallelepiped shape, and is formed by both end surfaces in the stacking direction (front-rear direction) of the negative electrode unit 31 and the positive electrode unit 32 and four side surfaces along the stacking direction. Since the configuration is the same as that of the negative electrode unit 31 and the positive electrode unit 32 described in the first embodiment, description thereof will be omitted.

  The separator 33 ″ of the inner laminate 3 ″ includes a plurality of inner separators 331 ″, a pair of end separators 332 ″, a pair of side separators (a left side separator 333L, a right side separator 333R), and a lower side described later Part separator 333D. The negative electrode unit 31 and the positive electrode unit 32 are alternately stacked along the front-rear direction across a plurality of internal separators 331 ″, and a pair of end separators 332 ″, 332 ″ are disposed on both end surfaces in the stacking direction (front-rear direction). In addition, the left side separator 333L is disposed along the stacking direction so as to form the left side surface of FIG. 17 among the four side surfaces of the inner laminate 3 ″, and the right side separator 333R is the inner laminate 3 ″. 17 are arranged along the stacking direction so as to form the right side surface of Fig. 17. The left end portions of all the internal separators 331 and the end separators 332 in the width direction form the left side separator 333L. Accordingly, as shown in FIG. 17, a space in which one end of the separator 33 ″ is closed by the left separator 333L extends in the stacking direction (front-rear direction). Formed Te, the respective space negative electrode unit 31 or the positive electrode unit 32 is disposed. The positive electrode unit 32 is disposed in the space between the end separator 332 ″ and the internal separator 331 ″ adjacent thereto, that is, the spaces located at both ends in the stacking direction. Further, the right end in the width direction of all the internal separators 331 ″ and the end separators 332 ″ may be connected to the right side separator 333R, but it is difficult to form the internal laminate 3 ″. In some cases, it may not be connected.

  18 is a cross-sectional view taken along the line XVIII-XVIII in FIG. As shown in FIG. 18, the lower separator 333D is connected to the lower end in the height direction of the end separator 332 ″ disposed at the front end of the inner laminate 3 ″ in the stacking direction (front-rear direction). . The lower side separator 333D is disposed on the lower side surface of FIG. 18 among the four side surfaces of the inner laminate 3 ″.

  19 is an expanded view of the outer negative electrode unit 4 ″, FIG. 19 (a) is a front view, and FIG. 19 (b) is a side view. As shown in FIG. 19, according to the present embodiment. The outer negative electrode unit 4 ″ includes a sheet-like outer negative electrode current collector 41 ″ and an outer negative electrode active material 42. The outer negative electrode current collector 41 ″ has a rectangular first portion 41a and second portion 41b, respectively. , A third portion 41c, a fourth portion 41d, and a fifth portion 41e. The first portion 41a, the second portion 41b, the third portion 41c, and the fourth portion 41d are connected in this order in the horizontal direction of FIG. Further, in FIG. 19 of the first portion 41a, the fifth portion 41e is connected to the lower end. A negative electrode lead portion A is formed in the upper left portion of the first portion 41a and the upper right portion of the third portion 41c. The first portion 41a and the third portion 41c have the same size and shape as the negative electrode current collector 311 of the negative electrode unit 31 (see FIG. 5).

  The outer negative electrode active material 42 is applied to one surface of the first portion 41a and the third portion 41c facing the same side. On the other hand, on the other side of the first portion 41a and the third portion 41c facing the same side, the second portion 41b, the fourth portion 41d, the fifth portion 41e, and the negative electrode lead portions A and A, the outer negative electrode active material 42 is Not coated. Of the second portion 41b, the fourth portion 41d, and the fifth portion 41e, the surface facing the same side as one surface (the surface coated with the outer negative electrode active material 42) of the first portion 41a and the third portion 41c (see FIG. The metal lithium 43 used when manufacturing the lithium ion capacitor 1 is attached to the black portion 13). Since the metallic lithium 43 is eluted as ions in the non-aqueous electrolyte 5 in the manufacturing process of the lithium ion capacitor 1, it is already lost when the manufacturing of the lithium ion capacitor 1 is completed, strictly, when the pre-doping is completed. Yes.

  As can be seen from FIGS. 16 and 18, the outer negative electrode unit 4 ″ has both end faces of the inner laminated body 3 ″ in the lamination direction (front-rear direction) of the negative electrode unit 31 and the positive electrode unit 32, and the width direction of the inner laminated body 3 ″. The inner laminate 3 ″ is covered so as to face the left and right side surfaces and the lower side surface in the height direction. That is, the outer negative electrode unit 4 ″ is disposed on five surfaces (both end surfaces and three side surfaces) of six surfaces (two end surfaces and four side surfaces) forming the rectangular parallelepiped inner laminated body 3 ″. A negative electrode lead portion A and a positive electrode lead portion B protrude from the side surface not covered with the outer negative electrode unit 4 ″. In this case, the negative electrode lead portion A and the positive electrode lead portion B are disposed on the front end surface of the inner stacked body 3 ″ in the stacking direction (front-rear direction). The outer negative electrode active material 42 applied to the first portion 41a of the outer negative electrode current collector 41 ″ is brought into contact with the end separator 332 ″, and the outer negative electrode is connected to the end separator 332 ″ disposed on the rear end surface. The outer negative electrode active material 42 applied to the third portion 41c of the current collector 41 ″ is in face-to-face contact. Further, the second portion 41b of the outer negative electrode current collector 41 ″ is disposed facing the left side separator 333L provided on the left side surface in the width direction of the inner laminated body 3 ″, and the fourth portion of the outer negative electrode current collector 41 ″ is arranged. The portion 41d is disposed to face the right side separator 333R provided on the right side surface in the width direction of the inner laminated body 3 ″. Further, the fifth portion 41e of the outer negative electrode current collector 41 ″ is disposed facing the lower side separator 333D provided on the lower side surface in the height direction of the inner stacked body 3 ″.

  Since other configurations are the same as those in the first embodiment, description thereof will be omitted.

  Next, a method for manufacturing a lithium ion capacitor according to this embodiment will be described.

(First step)
First, the inner laminated body 3 ″ is formed. That is, the negative electrode unit 31 and the positive electrode unit 32 are alternately laminated with the inner separator 331 ″ interposed therebetween. In addition, a pair of end separators 332 ″ and 332 ″ are disposed on both end surfaces in the stacking direction of the stacked body of the negative electrode unit 31 and the positive electrode unit 32. Further, the left separator 333L is disposed along the stacking direction so that the left separator 333L forms the left side in FIG. 17 of the inner laminate 3 ″, and the right separator 333R is the inner laminate 3 ″. 17, the right side separator 333 </ b> R is disposed along the stacking direction so as to form the right side surface. Further, the lower separator 333D is disposed along the stacking direction so that the lower separator 333D forms the lower surface in FIG. 18 of the inner stacked body 3 ″. A pair of end separators 332, 332 are arranged, the left side separator 333L is arranged on the left side, the right side separator 333R is arranged on the right side, and the lower side separator 333D is arranged on the lower side 3 '' Is formed.

(Second step)
Next, an outer negative electrode current collector 41 ″ is prepared. Then, an outer negative electrode active material 42 is applied to one surface of the first portion 41a and the third portion 41c of the prepared outer negative electrode current collector 41 ″, and the first The outer negative electrode unit 4 ″ is formed by attaching the metallic lithium 43 to one surface of the second portion 41b, the fourth portion 41d, and the fifth portion 41e. In this case, the metallic lithium 43 is surely connected to the outer negative electrode current collector. The metal lithium 43 may be pressure-bonded to the second portion 41b, the fourth portion 41d, and the fifth portion 41e so as to contact the second portion 41b, the fourth portion 41d, and the fifth portion 41e of 41 ′.

  Next, the inner laminate 3 ″ is covered with the outer negative electrode unit 4 ″. In this case, the first portion 41a of the outer negative electrode current collector 41 ″ is connected to the end separator 332 ″ arranged on the front end surface in the stacking direction (front-rear direction) of the negative electrode unit 31 and the positive electrode unit 32 in the inner stacked body 3 ″. The outer negative electrode is coated on the third portion 41c of the outer negative electrode current collector 41 ″ on the end separator 332 ″ disposed on the rear end surface in the stacking direction. The active material 42 faces, the metallic separator 43 pressed against the second portion 41b of the outer negative electrode current collector 41 ″ faces the left separator 333L disposed on the left side of the inner laminate 3 ″, and the inner The right side separator 333R disposed on the right side surface of the multilayer body 3 faces the metal lithium 43 pressed against the fourth portion 41d of the outer negative electrode current collector 41 ″, and further, on the lower side surface of the inner multilayer body 3 ″. Arrangement It is "As metallic lithium 43 is crimped to the fifth portion 41e of the faces, the internal laminate 3" outside the anode current collector 41 to the lower side separator 333D which covers the outer negative electrode unit 4 ". Thereby, the power storage unit 2 before pre-doping is formed.

(Third step)
Next, by connecting the negative electrode lead part A of the negative electrode current collector 311 and the outer negative electrode current collector 41 ″ with the negative electrode side conductive connecting member 25, all the negative electrode current collectors 311 and the outer negative electrode in the power storage unit 2 are connected. The current collector 41 ″ is electrically connected. In addition, by connecting the positive electrode lead portion B of the positive electrode current collector 321 with the positive electrode side conductive connection member 26, all the positive electrode current collectors 321 in the power storage unit 2 are electrically connected. Then, the power storage unit 2 is placed in the case 6, the negative electrode side conductive connection member 25 is connected to the negative electrode terminal 62, and the positive electrode side conductive connection member 26 is connected to the positive electrode terminal 61.

(4th process)
Thereafter, the nonaqueous electrolytic solution 5 is filled in the case 6. After filling, the positive electrode terminal 61 and the negative electrode terminal 62 are sandwiched in the opening of the case 6, and the opening portion is sealed by welding in that state. 20 and 21 are cross-sectional views of the lithium ion capacitor that has completed the fourth step.

  By filling the case 6 with the non-aqueous electrolyte 5 in the fourth step, the power storage unit 2 is immersed in the non-aqueous electrolyte 5. Thereby, the metal lithium 43 attached to the second portion 41b, the fourth portion 41d, and the fifth portion 41e of the outer negative electrode current collector 41 ″ of the power storage unit 2 is also immersed in the non-aqueous electrolyte 5. This metal lithium 43 is short-circuited to each negative electrode current collector 311 via the outer negative electrode current collector 41 ″ and the negative electrode side conductive connecting member 25. Therefore, the metal lithium 43 emits electrons to the outer negative electrode current collector 41 ″ and each negative electrode current collector 311, and is eluted as lithium ions in the nonaqueous electrolytic solution 5.

  Lithium ions eluted into the non-aqueous electrolyte 5 from the metal lithium 43 provided in the second portion 41b of the outer negative electrode current collector 41 ″ are transferred to the outer negative electrode unit 4 ″ in the power storage unit 2 along the width direction. While migrating the surface, the surface of each negative electrode unit 31 is migrated along the width direction through the left separator 333L. Then, lithium ions are occluded in the outer negative electrode active material 42 of the outer negative electrode unit 4 ″ and the negative electrode active material 312 of each negative electrode unit 31. Further, the metal provided in the fourth portion 41d of the outer negative electrode current collector 41 ″. Lithium ions eluted from the lithium 43 into the non-aqueous electrolyte 5 migrate on the surface of the outer negative electrode unit 4 ″ in the power storage unit 2 along the width direction, and pass through the right separator 333R to each negative electrode unit. The surface of 31 is migrated along the width direction, and lithium ions are occluded in the outer negative electrode active material 42 of the outer negative electrode unit 4 ″ and the negative electrode active material 312 of each negative electrode unit 31. Furthermore, the lithium ions eluted into the non-aqueous electrolyte 5 from the metal lithium 43 provided in the fifth portion 41e of the outer negative electrode current collector 41 ″ are removed from the outer negative electrode unit in the power storage unit 2 along the height direction. The surface of 4 ″ is migrated, and the surface of each negative electrode unit 31 is migrated along the height direction through the lower separator 334. Then, lithium ions are occluded in the outer negative electrode active material 42 of the outer negative electrode unit 4 ″ and the negative electrode active material 312 of each negative electrode unit 31. Thus, pre-doping is completed. When pre-doping is completed, the lithium ions are provided in the outer negative electrode unit 4. The metallic lithium 43 that has been lost disappears.

  As described above, according to the present embodiment, the metal lithium 43 attached to the outer negative electrode current collector 41 ″ faces the three side surfaces of the inner multilayer body 3 ″. Therefore, lithium ions eluted in the non-aqueous electrolyte 5 enter the inner laminated body 3 ″ from the three side surfaces of the inner laminated body 3 ″. The end of each negative electrode unit 31 is desired on the side surface of the inner laminated body 3 ″. Accordingly, lithium ions easily enter the negative electrode unit 31 from the end of each negative electrode unit 31, and each negative electrode unit 31. Accordingly, the negative electrode active material 312 provided in all the negative electrode units 31 and the outer negative electrode active material 42 provided in the outer negative electrode unit 4 ″ are uniformly predoped with lithium ions. Can do. Furthermore, according to the present embodiment, as shown in FIGS. 20 and 21, the metallic lithium 43 provided in the outer negative electrode unit 4 ″ is stacked in the stacking direction (front and rear) of the negative electrode unit 31 and the positive electrode unit 32 in the inner stacked body 3 ″. The inner laminated body 3 ″ is covered with the outer negative electrode unit 4 ″ so as to face the left side separator 333L, the right side separator 333R, and the lower side separator 333D over the entire area. That is, the metal lithium 43 faces the end portions of all the negative electrode units 31 of the inner laminate 3 ″ with the side separator interposed therebetween. Therefore, the lithium ions eluted in the non-aqueous electrolyte 5 are all negative electrode units. Thus, the negative electrode active materials 312 of all the negative electrode units 31 can be uniformly doped with lithium ions.

  In addition, according to the present embodiment, since lithium ions in the nonaqueous electrolyte solution 5 enter each negative electrode unit 31 from three directions, pre-doping progresses more efficiently, and the pre-doping time can be further shortened. The entire region in the negative electrode active material 312 on the two negative electrode current collectors 311 can be uniformly pre-doped with lithium ions.

  As mentioned above, although embodiment of this invention was described, this invention should not be limited to the said embodiment. For example, in each of the above-described embodiments, the example in which the shape of the inner laminated body is a rectangular parallelepiped shape has been described, but it may be a polygonal column shape or a cylindrical shape. That is, the inner laminate may have a shape having both end faces and side faces. Moreover, although the lithium ion capacitor was illustrated as an electrical storage device in the said embodiment, this invention is applicable also to the lithium battery by which lithium ion was pre-doped. Thus, the present invention can be modified without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 ... Lithium ion capacitor (electric storage device), 2 ... Electric storage unit, 3, 3 ', 3 "... Internal laminated body, 31 ... Negative electrode unit, 311 ... Negative electrode collector, 312 ... Negative electrode active material, 32 ... Positive electrode unit, 321 ... Positive electrode current collector, 322 ... Positive electrode active material, 33, 33 ', 33 "... Separator, 331, 331', 331" ... Internal separator, 332, 332 ', 332 "... End separator, 333 ... Side part Separator, 333D ... lower side separator, 333L ... left side separator, 333R ... right side separator, 4 ... outer negative electrode unit, 41 ... outer negative electrode current collector, 41a ... first part, 41b ... second part, 41c ... first 3 parts, 41d ... 4th part, 41e ... 5th part, 42 ... outside negative electrode active material, 43 ... metallic lithium, 5 ... non-aqueous electrolyte, 6 ... case

Claims (6)

A negative electrode unit having a flat negative electrode current collector and a negative electrode active material provided on both surfaces of the negative electrode current collector, a flat positive electrode current collector, and a positive electrode active material provided on both surfaces of the positive electrode current collector A first step of forming an inner laminate by alternately laminating positive electrode units having a separator therebetween,
A plate-like outer negative electrode current collector formed such that the first part, the second part, and the third part are connected in this order; an outer negative electrode active material provided on one surface of the first part and the third part; The outer negative electrode active material of the outer negative electrode unit having metal lithium provided in the second portion faces both end surfaces of the inner laminate, and the metal lithium faces side surfaces of the inner laminate. A second step of forming a power storage unit having the inner multilayer body and the outer negative electrode unit by covering the inner multilayer body with the outer negative electrode unit;
A third step of electrically connecting all the negative electrode current collector and the outer negative electrode current collector in the power storage unit;
By immersing the power storage unit in which all the negative electrode current collector and the outer negative electrode current collector are electrically connected in the third step in an electrolytic solution, the metal lithium is added to the negative electrode active material and the negative electrode active material. A fourth step of pre-doping the outer negative electrode active material;
A method for manufacturing an electricity storage device, comprising: In the manufacturing method of the electrical storage device according to claim 1,
The separator comprises an internal separator and a side separator;
In the first step, the negative electrode unit and the positive electrode unit are alternately stacked with the inner separator interposed therebetween, and the side separator is attached to the negative electrode so that the side separator forms a side surface of the inner stacked body. A step of forming the inner laminate by disposing the unit and the positive electrode unit along the lamination direction;
In the second step, the outer negative electrode active material of the outer negative electrode unit faces both end surfaces of the inner laminate, and the inner negative electrode unit causes the inner lithium electrode to face the side separator. A method for manufacturing an electricity storage device, which is a step of forming an electricity storage unit by covering a laminate. In the manufacturing method of the electrical storage device of Claim 2,
The separator further comprises a pair of end separators,
In the first step, the negative electrode unit and the positive electrode unit are alternately stacked with the inner separator interposed therebetween, the pair of end separators are disposed on both end surfaces of the inner stacked body, and the side separator Is a step of forming the inner laminate by disposing the side separator along the lamination direction of the negative electrode unit and the positive electrode unit so as to form a side surface of the inner laminate,
In the second step, the outer negative electrode active material of the outer negative electrode unit faces the end separator, and the inner laminate is formed by the outer negative electrode unit so that the metallic lithium faces the side separator. A method of manufacturing an electricity storage device, which is a step of forming an electricity storage unit by covering. A negative electrode unit having a flat negative electrode current collector and a negative electrode active material provided on both surfaces of the negative electrode current collector, a flat positive electrode current collector, and a positive electrode active material provided on both surfaces of the positive electrode current collector An internal laminate formed by alternately laminating the negative electrode unit and the positive electrode unit with the separator interposed therebetween,
A flat plate-like outer negative electrode current collector formed so that the first part, the second part, and the third part are connected in this order, and lithium ions are pre-doped on one surface of the first part and the second part. And covering the inner laminate so that the outer negative electrode active material faces both end faces of the inner laminate and the second portion faces a side surface of the inner laminate. An electricity storage unit comprising an outer negative electrode unit;
A case for storing the power storage unit therein;
An electrolyte filled in the case;
An electricity storage device comprising: The electricity storage device according to claim 4,
The separator comprises an internal separator and a side separator;
The negative electrode unit and the positive electrode unit are alternately stacked with the inner separator interposed therebetween,
The side separator is disposed along the stacking direction of the inner laminate so as to form a side surface of the inner laminate,
The electricity storage device, wherein the second portion is disposed facing the side separator. The electricity storage device according to claim 5,
The separator further comprises an end separator,
The end separator is disposed on both end faces of the inner laminate,
The electricity storage device, wherein the outer negative electrode active material provided in the first part and the second part is arranged to face the end separator.

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