JP5906912B2 - Power storage device - Google Patents

Description

  The present invention relates to a power storage device.

  Conventionally, lithium ion secondary batteries, nickel metal hydride secondary batteries, and the like are well known as secondary batteries that are a type of power storage device. For example, in a lithium ion secondary battery, an electrode sheet in which an active material is applied to the surface of a metal sheet is laminated or wound with a separator sandwiched therebetween to form an electrode body, and the electrode body is accommodated in a case (For example, patent document 1).

  In patent document 1, while containing an electrode body in the bag-shaped film which consists of resin material which has insulation, the electrode body covered with the bag-shaped film is accommodated in a case, and it suppresses that an electrode body and a case contact. doing.

JP 2010-287456 A

  By the way, the power storage device as described above is often used in an environment where vibration is repeatedly applied, for example, by being mounted on a vehicle. When such vibration is applied to the power storage device, the electrode body moves (swings) in the case, so that the active material is not applied to each electrode sheet constituting the electrode body ( There is a possibility that a load is applied to a connection portion between a so-called electrode lead portion) and a current collecting member connected to an external terminal.

  The present invention has been made paying attention to the problems existing in the above-described prior art, and an object thereof is to provide a power storage device capable of suppressing the movement of the electrode body in the case.

In order to solve the above-mentioned problem, the invention described in claim 1 is characterized in that a sheet-like separator is sandwiched between an electrode sheet for a positive electrode and an electrode sheet for a negative electrode in which an active material is applied to at least one surface of a metal sheet. An electrode body that has a layered structure in an open state and a metal case that houses the electrode body, and the active material is not applied to the positive electrode sheet and the negative electrode sheet a electrically connected to Tei Ru power storage device and the external terminal by the current collecting member provided in part with said casing is formed of a resin material having insulation properties, houses the electrode body in said casing comprising a bag-like insulating member you are, with the insulating member, an inner wall surface of the casing, when viewed from the laminating direction of the electrode body, that the region overlapping with the electrode body is heat-welded And effect.

According to this, since the insulating member is formed in a bag shape and accommodates the electrode body, or formed in a sheet shape and fixed to the electrode body, the electrode body moves relative to the insulating member. It is suppressed. The insulating member and the inner wall surface of the case are thermally welded. For this reason, it can suppress that an electrode body moves in a case by the vibration added to an electrical storage apparatus. Further, since the insulating member is formed in a bag shape and accommodates the electrode body, for example, the insulating member and the electrode body move relatively as compared with a configuration in which a sheet-like insulating film is fixed to the electrode body. This can be easily and suitably suppressed.

  According to a second aspect of the present invention, in the power storage device according to the first aspect, the electrode sheet disposed on the outermost side of the electrode body is the electrode sheet for the negative electrode, and the metal in the electrode sheet for the negative electrode The gist of the present invention is that the active material applied to the sheet includes a material having a thermal conductivity lower than that of the carbon-based active material, and is made of a material capable of removing and inserting lithium ions.

  According to this, when heat-welding by heating from the outside of the case, heat can be prevented from being transmitted to the separator sandwiched between the negative electrode sheet and the positive electrode sheet. Therefore, it can suppress that a separator melts at the time of heat welding.

The invention according to claim 3 is the power storage device according to claim 2, wherein the active material of the electrode sheet for the negative electrode contains silicon dioxide.
According to this, since the active material of the electrode sheet for the negative electrode contains silicon dioxide, heat is transferred to the separator via the electrode sheet for the negative electrode when heated from the outside of the case and thermally welded. Can be suitably suppressed by the active material.

  According to a fourth aspect of the present invention, in the power storage device according to any one of the first to third aspects, the outer surface of the electrode body has a flat portion, and the insulating member and the case are located at the position of the flat portion. The gist is that the inner wall surface is thermally welded. According to this, since the insulating member and the inner wall surface of the case are thermally welded at the position of the plane portion, the case and the insulating member can be more reliably fixed.

  According to a fifth aspect of the present invention, in the power storage device according to any one of the first to third aspects, the outer surface of the electrode body has a flat portion, and the insulating member is disposed on a peripheral portion of the flat portion. The gist is that the inner wall surface of the case is thermally welded along.

  According to this, since the insulating member is thermally welded to the inner wall surface of the case along the peripheral edge portion of the flat portion of the electrode body, the heat applied when the heat welding is performed is transmitted to the separator. However, compared with the case where heat welding is performed at the center of the flat portion of the electrode body, for example, the range in which heat is transmitted to the separator can be kept small.

  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 electrode body includes a plurality of the positive electrode sheets, a plurality of the negative electrode sheets, and a plurality of the negative electrode sheets. It is summarized that the separator is laminated. According to this, an electrode body can be simply formed by laminating | stacking each electrode sheet for positive electrodes and negative electrodes, and a separator.

  The invention according to claim 7 is the power storage device according to any one of claims 1 to 6, wherein the uncoated portion formed on the electrode sheet for the positive electrode and the electrode sheet for the negative electrode The summary is that the formed uncoated part is arranged on the same edge side of the electrode body.

  According to this, since the uncoated portions formed on the electrode sheets for the positive electrode and the negative electrode are arranged on the same edge side in the electrode body, each uncoated portion is connected to a different edge in the electrode body. The dead space in the case can be reduced and the energy density as the power storage device can be improved as compared with the case where it is arranged on the part side.

The invention according to claim 8 is the power storage device according to any one of claims 1 to 7 , wherein the power storage device is a secondary battery.
According to this, since the movement of the electrode body in the case can be suppressed as a power storage device that is a secondary battery, the connection between the uncoated portion and the current collecting member in each electrode sheet is caused by vibration generated during traveling or the like. It can suppress that a load is added to a part.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that an electrode body moves within a case.

The perspective view which shows a secondary battery typically. The perspective view which shows typically the decomposed | disassembled electrode body. The AA sectional view taken on the line of the secondary battery shown in FIG. The BB sectional view taken on the line of the secondary battery shown in FIG. The perspective view which shows typically the decomposed | disassembled electrode body in another embodiment. Sectional drawing which shows the secondary battery in another embodiment typically.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, a lithium ion secondary battery (hereinafter simply referred to as “secondary battery”) 10 as a power storage device mounted on a vehicle (for example, an industrial vehicle or a passenger vehicle) has a generally flat, rectangular parallelepiped shape. A case 11 is provided. The case 11 has a flat plate shape (this embodiment) assembled to the main body member 12 so as to seal the main body member 12 formed in a bottomed cylindrical shape (square tube shape in the present embodiment) and the opening 12a of the main body member 12. It is formed from a lid member 13 having a rectangular flat plate shape.

  The main body member 12 and the lid member 13 are both made of metal (for example, stainless steel or aluminum). In the following description, the longitudinal direction of the case 11 indicated by the arrow Y1 is indicated as the left-right direction, the height direction of the case 11 indicated by the arrow Y2 is indicated as the vertical direction, and the short direction of the case 11 indicated by the arrow Y3 is indicated as the front-back direction. Show.

  On the outer surface (upper surface) of the lid member 13, a positive electrode terminal 15 serving as a columnar (substantially columnar) external terminal and a negative electrode terminal 16 serving as an external terminal are formed so as to protrude. The secondary battery 10 of the present embodiment is charged and discharged through the positive terminal 15 and the negative terminal 16. The positive terminal 15 and the negative terminal 16 are insulated from the case 11 (the main body member 12 and the lid member 13).

  Further, the case 11 (main body member 12) accommodates (accommodates) an electrode body 18 having a rectangular parallelepiped shape (substantially rectangular parallelepiped shape) that is flat in the left-right direction as a whole. In this electrode body 18, a positive electrode sheet 21 as a positive electrode sheet and a negative electrode sheet 31 as a negative electrode sheet have a layered structure with a separator 19 interposed therebetween.

  As shown in FIG. 2, the positive electrode sheet 21 includes a positive electrode metal foil 22 as a metal sheet (metal thin plate) having a rectangular sheet shape. The negative electrode sheet 31 includes a negative electrode metal foil 32 as a metal sheet (metal thin plate) having a rectangular sheet shape. In the present embodiment, the positive electrode metal foil 22 is made of, for example, aluminum, while the negative electrode metal foil 32 is made of, for example, copper.

On both surfaces (front surface and rear surface) of the positive electrode metal foil 22, except for the positive electrode uncoated portion 24 a set with a constant width over the entire width in the left-right direction from the upper edge portion 23 which is one side of the positive electrode metal foil 22, A positive electrode active material (an active material mixture containing a positive electrode active material) is applied to the entire surface to form a positive electrode active material layer 24. In the present embodiment, the region where the positive electrode active material layer 24 is formed becomes the positive electrode coating portion 24b. As the positive electrode active material, for example, LiNi _1/3 Mn _1/3 Co _1/3 O ₂ or the like is used.

  Further, on both surfaces (front surface and rear surface) of the negative electrode metal foil 32, except for the negative electrode uncoated portion 34 a set with a constant width from the upper edge 33 which is one side of the negative electrode metal foil 32 over the entire width in the left-right direction. The negative electrode active material (active material mixture containing the negative electrode active material) is applied to the entire surface, and the negative electrode active material layer 34 is formed. In the present embodiment, the region where the negative electrode active material layer 34 is formed becomes the negative electrode coating portion 34b.

  Here, as the negative electrode active material, a material including a material having a thermal conductivity lower than that of the carbon (carbon) active material and capable of removing and inserting lithium ions is used. In the present embodiment, a composite (mixture) of silicon dioxide (silicon dioxide) and silicon (silicon) is used as the negative electrode active material. Here, the thermal conductivity of silicon dioxide is 1 Wm / K to 2 Wm / K, which is lower than the thermal conductivity of the carbon-based active material (119 Wm / K to 165 Wm / K). Moreover, the thermal conductivity as a composite of silicon dioxide and silicon is lower than the thermal conductivity of the carbon-based active material.

  A positive electrode lead 25 having a quadrangle (substantially square) is formed on the left side of the upper edge 23 of the positive electrode sheet 21 so as to extend upward. In the present embodiment, the positive electrode lead 25 forms a part of the positive electrode uncoated portion 24a. Further, a negative electrode lead 35 having a quadrangular shape (substantially square shape) is formed to extend upward on the right side of the upper edge portion 33 of the negative electrode sheet 31. In the present embodiment, the negative electrode lead 35 forms a part of the negative electrode uncoated portion 34a.

  In this embodiment, the length along the vertical direction in the negative electrode coating portion 34b is longer than the length along the vertical direction in the positive electrode coating portion 24b, and the length along the left and right direction in the negative electrode coating portion 34b is , Longer than the length along the left-right direction in the positive electrode coating portion 24b. That is, the negative electrode coating part 34b is formed larger than the positive electrode coating part 24b in a front view.

  The separator 19 has a porous sheet shape made of polyethylene and having a finer pore structure (pores) than that of the base material layer on both surfaces of the base material layer forming a porous sheet shape made of polypropylene. It has a three-layer structure with a pore layer formed.

  When the separator 19 reaches the melting point (for example, 135 ° C. to 140 ° C.) of the resin material (polyethylene) constituting the pore layer, the pore layer melts, the pore structure collapses, and the pores are blocked. It is. Thereby, the current (passage of ions) between the positive electrode sheet 21 and the negative electrode sheet 31 is interrupted (so-called shutdown). In the following description, the temperature at which the pore structure of the pore layer collapses is simply referred to as “cutoff temperature”.

  Moreover, the length along the left-right direction in the separator 19 is longer than the length along the left-right direction of the positive electrode sheet 21 and the negative electrode sheet 31. Similarly, the length along the vertical direction in the separator 19 is the length from the lower edge to the upper edge 23 in the positive electrode sheet 21 and the length from the lower edge to the upper edge 33 in the negative electrode sheet 31. Longer than that.

  The electrode body 18 is formed by alternately laminating the positive electrode sheets 21 and the negative electrode sheets 31 in the front-rear direction (thickness direction) with the separator 19 sandwiched between the positive electrode sheet 21 and the negative electrode sheet 31. Is formed. In the present embodiment, the horizontal direction indicated by the arrow Y1 and the vertical direction indicated by Y2 are the surface directions of the positive electrode sheet 21, the negative electrode sheet 31, and the separator 19, and the front-rear direction indicated by the arrow Y3 is the electrode body 18 (positive electrode). It becomes a lamination direction in the sheet 21 and the negative electrode sheet 31). That is, the direction orthogonal to the surface direction of the positive electrode sheet 21 and the negative electrode sheet 31 coincides with the stacking direction in the electrode body 18.

  In addition, among the positive electrode sheet 21 and the negative electrode sheet 31 constituting the electrode body 18, the electrode sheet disposed on the outermost side (both ends) in the stacking direction in the electrode body 18 is a negative electrode sheet 31. Yes. Further, in the electrode body 18, when viewed from the stacking direction of the positive electrode sheet 21 and the negative electrode sheet 31 constituting the electrode body 18, the positive electrode coating portion 24 b in the positive electrode sheet 21 is coated with the negative electrode in the negative electrode sheet 31. It is included (included) in the engineering part 34b.

  As shown in FIG. 1, on the left side of the upper edge of the electrode body 18, a positive electrode current collector having a layered structure in the stacking direction with the positive electrode lead 25 sandwiching no separator 19 therebetween 28 is formed. In addition, a negative electrode current collecting portion 38 having a layered structure in the stacking direction is formed on the right side of the upper edge portion of the electrode body 18 in a state where the negative electrode lead 35 does not sandwich the separator 19 therebetween. . Thus, in this embodiment, the positive electrode uncoated part 24a (positive electrode lead 25) formed on the positive electrode sheet 21 and the negative electrode uncoated part 34a (negative electrode lead 35) formed on the negative electrode sheet 31 are formed. Are disposed on the same edge side (upper edge side in the present embodiment) of the electrode body 18.

  As shown in FIGS. 3 and 4, the electrode body 18 of the present embodiment includes a stacking direction in the electrode body 18, a direction from the opening 12 a of the main body member 12 to the bottom (the standing direction of the side wall portion). Is inserted into the main body member 12 in a state perpendicular to the vertical direction. That is, in the secondary battery 10 of the present embodiment, the stacking direction in the electrode body 18 and the insertion direction of the electrode body 18 with respect to the main body member 12 are orthogonal to each other.

  Moreover, the electrode body 18 is accommodated in the case 11 (main body member 12) in the state accommodated in the insulating bag 40 as an insulating member formed from the resin material which has insulation. The insulating bag 40 is formed by forming an insulating film made of an insulating resin material such as polypropylene or polyethylene into a bag shape. The insulating bag 40 of the present embodiment is formed from a polyethylene film (sheet). The insulating bag 40 is formed to be slightly larger than the electrode body 18, and the electrode body 18 and the insulating bag 40 are in close contact with each other and moved relatively when the electrode body 18 is accommodated in the insulating bag 40. It is fixed impossible.

  For this reason, the insulating bag 40 is interposed between the end surfaces (the front end surface 18a and the rear end surface 18b) of the electrode body 18 in the stacking direction and the inner wall surface 12b of the main body member 12 facing the end surfaces 18a, 18b. . Since the insulating bag 40 of the present embodiment is formed in a bag shape, except for the extending direction of the positive electrode current collector 28 and the negative electrode current collector 38 in the electrode body 18 (upward in this embodiment), It is interposed between the case 11 (main body member 12) throughout.

  The insulating bag 40 and the inner wall surface 12b of the main body member 12 facing the front end surface 18a in the stacking direction of the electrode body 18 are fixed to each other by thermal welding. More specifically, the insulating bag 40 and the inner wall surface 12b of the main body member 12 include the negative electrode coating portion 34b of the negative electrode sheet 31 constituting the electrode body 18 when viewed from the stacking direction of the electrode body 18. The entire overlapped area (entire surface) is thermally welded and fixed (area shown in black in FIGS. 3 and 4). That is, in this embodiment, the front end surface 18a of the electrode body 18 becomes a flat portion, and the insulating bag 40 and the inner wall surface 12b of the main body member 12 are thermally welded at the position of the front end surface 18a. In the following description, a region where the insulating bag 40 and the inner wall surface 12b of the main body member 12 are thermally welded is referred to as a welding region 40a.

  As shown in FIG. 1, the positive electrode current collector 28 (positive electrode lead 25) is joined and electrically connected to the tip (one end) of a positive electrode current collector terminal 41 as a current collector. The base end (the other end) of the positive electrode current collecting terminal 41 is electrically connected to the positive electrode terminal 15 described above. The negative electrode current collector 38 (negative electrode lead 35) is joined and electrically connected to the tip (one end) of a negative electrode current collector terminal 42 as a current collector. The base end (the other end) is electrically connected to the negative electrode terminal 16 described above. The case 11 is filled with an electrolyte (electrolytic solution) (not shown).

Next, the effect | action of the secondary battery 10 of this embodiment is demonstrated.
Since the insulating bag 40 of this embodiment is formed in a bag shape and accommodates the electrode body 18, it is suppressed that the electrode body 18 moves relative to the insulating bag 40. The insulating bag 40 is thermally welded to the inner wall surface 12b of the main body member 12 (case 11) facing the front end surface 18a of the electrode body 18 in the stacking direction. For this reason, it is possible to prevent the electrode body 18 from moving (swinging) in the case 11 due to vibration applied to the secondary battery 10.

  For this reason, the electrode body 18 is repeatedly moved (swinged) in the case 11, thereby connecting (joining) the positive electrode current collector 28 and the positive electrode current collector terminal 41, or the negative electrode current collector 38 and the negative electrode current collector 41. It can suppress suitably that a load concentrates on the connection (joining) part with the electric terminal 42. FIG. Therefore, it is possible to suppress the occurrence of fine cracks in the positive electrode lead 25 and the negative electrode lead 35 and the performance of the secondary battery 10 such as the electric capacity being lowered.

  In the present embodiment, among the positive electrode sheet 21 and the negative electrode sheet 31 constituting the electrode body 18, the electrode sheets arranged on the outermost side (both ends) in the stacking direction in the electrode body 18 are both negative electrodes. The sheet 31 is used. And as a negative electrode active material, the composite_body | complex (mixture) containing the silicon dioxide whose heat conductivity is lower than a carbon type active material is used.

  Here, as shown in FIG. 3 and FIG. 4, in this embodiment, the inner wall surface 12 b of the main body member 12 and the insulating bag 40 are in a state where the secondary battery 10 is supported by the support jig 45. The heat welding jig 46 is pressed against the main body member 12 from the front surface side and heated by the heat welding jig 46 to be heat welded. More specifically, the heat transmitted from the heat welding jig 46 to the main body member 12 is transmitted to the insulating bag 40 through the inner wall surface 12b, whereby the insulating bag 40 is melted and heat welding is performed. In this embodiment, the heat welding jig 46 is used to heat to a temperature higher than the melting point of polyethylene forming the insulating bag 40.

  However, when the heat transferred to the insulating bag 40 is further transferred to the electrode body 18 and the temperature of the electrode body 18 reaches the cutoff temperature of the separator 19, the pore layer in the separator 19 constituting the electrode body 18. Melts to close the pores (so-called shutdown). In such a case, the internal resistance of the secondary battery 10 is increased, leading to a decrease in performance such as electric capacity.

  On the other hand, in the secondary battery 10 of the present embodiment, the negative electrode sheet 31 using a composite (mixture) containing silicon dioxide as the negative electrode active material is disposed on the outermost side in the stacking direction of the electrode body 18. . That is, as shown in FIG. 3, in this embodiment, from the outside of the main body member 12, the main body member 12 (wall portion of the main body member 12) → insulation bag 40 → negative electrode sheet 31 (negative electrode active material layer 34 → negative electrode metal) Each member is arranged in the order of foil 32 → negative electrode active material layer 34) → separator 19 → positive electrode sheet 21 → separator 19 → negative electrode sheet 31. For this reason, in this embodiment, it is suppressed that the heat transmitted to the insulating bag 40 is further transmitted to the electrode body 18 (the separator 19 sandwiched between the negative electrode sheet 31 and the positive electrode sheet 21), It is suitably suppressed that the separator 19 is melted at the time of heat welding.

  Further, for example, it is conceivable to fix the insulating bag 40 and the inner wall surface 12b by bonding them with an adhesive (adhesive or adhesive tape). However, in the secondary battery 10 of the present embodiment, it is necessary to insert the electrode body 18 into the main body member 12 along a direction (vertical direction in the present embodiment) orthogonal to the stacking direction of the electrode body 18. For this reason, when the electrode body 18 covered with the insulating bag 40 is inserted into the main body member 12 in a state where the adhesive material is disposed on the inner wall surface 12b of the main body member 12, it is difficult to insert the electrode body 18 in contact with the adhesive material. .

  In addition, when the insulating bag 40 and the inner wall surface 12b are fixed with an adhesive, the thickness of the adhesive may be uneven. In such a case, when a plurality of secondary batteries 10 are stacked (parallelly arranged) in the front-rear direction to form a module, a load is uniformly applied to the electrode body 18, and the positive electrode sheet 21 and the negative electrode It becomes difficult to make the reaction between the sheet 31 uniform. On the other hand, in this embodiment, the insulating bag 40 and the inner wall surface 12b are fixed by heat welding, and such a problem is solved suitably.

  Further, when the insulating bag 40 and the inner wall surface 12b are bonded and fixed, it is necessary to dispose the adhesive on the inner wall surface 12b of the main body member 12 or to solidify (dry) the adhesive. On the other hand, in this embodiment, since the insulating bag 40 and the inner wall surface 12b can be fixed to each other by one process of performing heat welding, the secondary battery 10 is compared with the case where an adhesive is used. This process can be simplified and the time required for manufacturing the secondary battery 10 can be shortened.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) Since the insulating bag 40 is formed in a bag shape and accommodates the electrode body 18, it is possible to suppress the electrode body 18 from moving relative to the insulating bag 40. The insulating bag 40 is thermally welded to the inner wall surface 12b of the main body member 12 (case 11) facing the front end surface 18a of the electrode body 18 in the stacking direction. For this reason, the movement of 18 in the case 11 due to vibration applied to the secondary battery 10 can be suppressed.

  (2) In the present embodiment, the negative electrode sheet 31 using a composite (mixture) containing silicon dioxide having a thermal conductivity lower than that of the carbon-based active material as the negative electrode active material is disposed on the outermost side in the stacking direction of the electrode body 18 ( It is arranged on both ends. For this reason, when heat-welding by heating from the outside of the case 11, heat is sandwiched between the positive electrode sheet 21 and the negative electrode sheet 31 by the negative electrode sheet 31 disposed on the outermost side of the electrode body 18. The transmission to the separator 19 can be suppressed. Therefore, it can suppress that the separator 19 fuse | melts at the time of heat welding.

  (3) Since the active material of the negative electrode sheet 31 contains silicon dioxide, it is preferable that heat is transferred to the separator 19 via the negative electrode sheet 31 when heat-welding by heating from the outside of the case 11. Can be suppressed.

  (4) The insulating bag 40 and the inner wall surface 12b of the case 11 (main body member 12) are thermally welded at the position of the front end face 18a. For this reason, case 11 and insulating bag 40 can be fixed more reliably.

(5) The electrode body 18 is formed by laminating a positive electrode sheet 21, a negative electrode sheet 31, and a separator 19. Therefore, the electrode body 18 can be easily formed.
(6) The positive electrode uncoated portion 24 a formed on the positive electrode sheet 21 and the negative electrode uncoated portion 34 a formed on the negative electrode sheet 31 are arranged on the same edge side of the electrode body 18. For this reason, compared with the case where the positive electrode uncoated part 24a and the negative electrode uncoated part 34a are arrange | positioned in a different edge part side, the dead space in the case 11 is reduced and the energy density as the secondary battery 10 is reduced. Can be improved.

  (7) Moreover, since the insulating bag 40 is formed in a bag shape that accommodates the electrode body 18, the insulating bag 40 and the electrode are compared with a configuration in which, for example, a sheet-like insulating film is attached to the electrode body 18. The relative movement of the body 18 can be easily and reliably suppressed.

The embodiment is not limited as described above, and may be embodied as follows, for example.
As shown in FIG. 5, the electrode body 18 has a positive electrode sheet 21, a negative electrode sheet 31, and a separator 19 formed in a strip shape (long sheet shape), with the separator 19 interposed therebetween, The positive electrode sheet 21 and the negative electrode sheet 31 may be wound in a spiral shape so that the positive electrode sheet 21 and the negative electrode sheet 31 form a layered structure (layered). In this case, the positive electrode lead 25 is extended and formed at a predetermined interval in the length direction of the positive electrode sheet 21 on the upper edge portion 23 of the positive electrode sheet 21, while the upper edge portion 33 of the negative electrode sheet 31 is formed on the upper edge portion 33. The negative electrode leads 35 are extended and formed at predetermined intervals in the length direction of the negative electrode sheet 31. Then, by winding the positive electrode sheet 21 and the negative electrode sheet 31, a layered structure (layered shape) is formed on the left side of the upper edge portion of the electrode body 18 with the positive electrode lead 25 not sandwiching the separator 19 therebetween. The positive electrode current collector portion 28 is formed to extend upward. Further, on the right side of the upper edge portion of the electrode body 18, a negative electrode current collecting portion 38 having a layered structure (layered shape) in a state where the negative electrode lead 35 does not sandwich the separator 19 therebetween is formed. 5 shows an example of the wound electrode body 18 that has a flat shape in the left-right direction and the up-down direction. However, the wound electrode body 18 is formed in a cylindrical shape that extends along the direction in which the winding axis extends (up-down direction). May be. In this case, the main body member 12 may be formed in a bottomed cylindrical shape.

  In place of the insulating bag 40, an insulating film (insulating sheet) as an insulating member made of an insulating resin material is fixed to the front end surface 18a and the rear end surface 18b of the electrode body 18, and the insulating film and the main body member 12 are fixed. The inner wall surface 12b may be heat welded. The insulating film and the electrode body 18 are preferably fixed with an adhesive tape. Further, in place of the insulating bag 40, an insulating layer as an insulating member made of an insulating resin material is used as the electrode body 18 of the negative electrode sheet 31 disposed on the outermost side (both ends) of the electrode body 18. You may form in the surface of the negative electrode active material layer 34 arrange | positioned outside. Thus, the insulating member may be fixed to the electrode body 18.

  The insulating bag 40 may be thermally welded to the inner wall surface 12b of the case 11 (main body member 12) along the peripheral edge portion of the front end surface 18a that is the end surface (plane portion) in the stacking direction of the electrode body 18. For example, as shown in FIG. 6, among the peripheral portions of the front end face 18 a, heat welding may be performed in welding regions 40 a set along the upper edge portion (upper side portion) and the lower edge portion (lower side portion), respectively. Alternatively, heat welding may be performed in the welding region 40a set over the entire circumference of the peripheral edge portion of the front end face 18a. According to this, since the insulating bag 40 is thermally welded to the inner wall surface 12b of the case 11 along the peripheral edge portion of the front end face 18a of the electrode body 18, the heat applied in the case of thermal welding is temporarily separated. Even in the case where the heat is transmitted to the separator 19, for example, compared to the case where heat welding is performed at the center of the front end surface 18 a of the electrode body 18 when viewed from the front, the range in which heat is transmitted to the separator 19 can be reduced. In particular, in the electrode body 18 of the present embodiment, the positive electrode coating portion 24b in the positive electrode sheet 21 is included in the negative electrode coating portion 34b in the negative electrode sheet 31 when viewed from the front. Even if 19 is melted, its influence can be minimized.

  The insulating bag 40 and the inner wall surface 12b may be heat-welded over the entire region overlapping the electrode body 18 in a front view, or may be heat-welded in a part of the region. For example, it may be heat-welded at a plurality of spots in a spot shape.

  The insulating bag 40 may be thermally welded to the inner wall surface 12b of the main body member 12 facing the rear end surface 18b in addition to or instead of the inner wall surface 12b facing the front end surface 18a of the electrode body 18.

  The main body member 12 may be formed in a square box shape that opens to a flat surface (front surface or rear surface). In this case, the electrode body 18 is inserted (accommodated) into the main body member 12 in a state where the stacking direction of the electrode body 18 and the direction from the opening of the main body member 12 toward the bottom wall portion coincide. When configured in this manner, the insulating bag 40 and the lid member 13, or the insulating bag 40 and the bottom wall portion of the main body member 12 can be thermally welded, and then the lid member 13 can be assembled to the main body member 12.

  As a negative electrode active material, silicon monoxide (silicon monoxide, SiO), lithium titanate, and lithium silicate can be used. As the negative electrode active material, a mixture of graphite and silicon dioxide can be used. In other words, the negative electrode active material may be any material that includes a material having a thermal conductivity lower than that of the carbon-based active material and is capable of removing and inserting lithium ions.

  ○ Although the positive electrode metal foil 22 and the negative electrode metal foil 32 were used as the metal sheets, they may be thin sheet-like sheets having a thickness that does not affect the battery capacity (electric capacity) of the secondary battery 10 or the battery production. .

  The positive electrode sheet 21 may form a positive electrode active material layer 24 by applying a positive electrode active material only to one surface of the positive electrode metal foil 22. Similarly, the negative electrode sheet 31 may apply the negative electrode active material only to one surface of the negative electrode metal foil 32 to form the negative electrode active material layer 34.

The electrode body 18 may be laminated by folding the positive electrode sheet 21 and the negative electrode sheet 31 in a bellows shape with the separator 19 interposed therebetween.
(Circle) you may change suitably the number of the positive electrode sheets 21 and the negative electrode sheets 31 which comprise the electrode body 18. FIG. For example, the electrode body 18 including one positive electrode sheet 21 and one negative electrode sheet 31 may be used.

The shape of the case 11 may be formed in a columnar shape or an elliptical column shape that is flat in the left-right direction.
○ The secondary battery 10 of the above embodiment is mounted on a vehicle (for example, an industrial vehicle or a passenger vehicle), and is charged by a generator mounted on the vehicle, while the compressor for an air conditioner is supplied with electric power supplied from the secondary battery 10 Alternatively, an electric motor for driving the wheels or an electrical component such as a car navigation system may be driven. According to this, since the movement (swing) of the electrode body 18 in the case 11 can be suppressed as the secondary battery 10, the positive electrode uncoated portion 24 a in the positive electrode sheet 21 is caused by vibration generated during traveling and the like. It can suppress that a load is added to the connection part with the positive electrode current collection terminal 41. FIG. The same applies to the connection portion between the negative electrode uncoated portion 34 a and the negative electrode current collector terminal 42 in the negative electrode sheet 31. Therefore, it can suppress suitably that performance, such as an electric capacity, falls with the damage of the said connection part, and can suppress that the replacement cycle of the secondary battery 10 becomes short.

  The present invention may be embodied as a nickel hydride secondary battery or an electric double layer capacitor. In other words, the present invention can be applied to a power storage device formed to be chargeable and dischargeable.

  DESCRIPTION OF SYMBOLS 10 ... Lithium ion secondary battery (electric storage apparatus), 11 ... Case, 12 ... Main body member, 12b ... Inner wall surface, 13 ... Cover member, 15 ... Positive electrode terminal (external terminal), 16 ... Negative electrode terminal (external terminal), 18 DESCRIPTION OF SYMBOLS ... Electrode body, 18a ... Front end surface (plane part), 19 ... Separator, 21 ... Positive electrode sheet (electrode sheet), 22 ... Positive electrode metal foil (metal sheet), 24 ... Positive electrode active material layer, 24a ... No positive electrode coating , 31 ... Negative electrode sheet (electrode sheet), 32 ... Negative electrode metal foil (metal sheet), 34 ... Negative electrode active material layer, 34a ... Negative electrode uncoated part, 40 ... Insulating bag (insulating member), 41 ... Positive electrode collection Electrical terminal (current collecting member), 42... Negative electrode current collecting terminal (current collecting terminal).

Claims (8)

A positive electrode sheet coated with an active material on at least one surface of a metal sheet, and an electrode body having a layered structure with a sheet-like separator sandwiched between the negative electrode sheet and the electrode body are accommodated A non-coated portion where the active material is not applied in the positive electrode sheet and the negative electrode sheet and an external terminal provided in the case is electrically connected by a current collecting member. a connected Tei Ru power storage device,
Is formed of a resin material having insulation properties, comprising a bag-shaped insulating member that accommodates the electrode body in said casing,
The power storage device, wherein the insulating member and the inner wall surface of the case are heat-welded in a region overlapping with the electrode body when viewed from the stacking direction of the electrode body . The electrode sheet disposed on the outermost side of the electrode body is an electrode sheet for the negative electrode,
The active material applied to the metal sheet in the electrode sheet for the negative electrode includes a material having a thermal conductivity lower than that of the carbon-based active material, and is made of a material capable of removing and inserting lithium ions. The power storage device according to claim 1.   The power storage device according to claim 2, wherein the active material of the negative electrode sheet contains silicon dioxide.   The outer surface of the electrode body has a flat portion, and the insulating member and the inner wall surface of the case are thermally welded at the position of the flat portion. The power storage device described.   The outer surface of the electrode body has a flat portion, and the insulating member is thermally welded to the inner wall surface of the case along the peripheral edge of the flat portion. 2. The power storage device according to item 1.   6. The electrode body according to claim 1, wherein the electrode body is formed by laminating a plurality of electrode sheets for the positive electrode, a plurality of electrode sheets for the negative electrode, and a plurality of the separators. Power storage device.   The uncoated part formed on the electrode sheet for the positive electrode and the uncoated part formed on the electrode sheet for the negative electrode are arranged on the same edge side in the electrode body. The power storage device according to any one of claims 1 to 6. The power storage device according to any one of claims 1 to 7 , wherein the power storage device is a secondary battery.