JP2014002858A - Electrode storage separator and power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode storage separator in which a pair of separators can be fixed firmly while storing an electrode internally, even when separators coated with ceramics are used, and to provide a power storage device.SOLUTION: An electrode storage bag-shaped separator 10 is an electrode integrated separator storing a positive electrode sheet 13 in a pair of bag-shaped separator sheets 29. The separator sheet 29 consists of five layers of an outer ceramics layer/an outer PP layer/a PET layer/an inner PP layer/an inner ceramics layer. At an end of the separator sheet 29, exposed parts 32 (32a, 32b) is provided so that a part of the PE layer is exposed to the outside. The pair of separator sheets 29 are fixed in bag-shape by welding the exposed parts 32 having a low melting point each other.

Description

  The present invention relates to an electrode storage separator in which an electrode is stored and a power storage device.

  As is well known, rechargeable secondary batteries can be used repeatedly, and are therefore widely used in various devices and apparatuses. In the field of vehicles, the use of fossil fuels (reduction of carbon dioxide emissions) is required, so vehicles that use this type of secondary battery as a motor power source, so-called hybrid vehicles and EV vehicles (Electric Vehicle vehicles) ) And so on. In such a secondary battery, charging and discharging with a large current and an increase in battery capacity are required. For example, lithium ion secondary batteries are mass-produced as products.

  As a secondary battery of this type, for example, a secondary battery having a laminated structure in which a positive electrode sheet, a negative electrode sheet, and a separator that insulates them are alternately stacked to form an electrode body is well known. However, since the laminated structure undergoes a manufacturing process in which the positive electrode sheet, the negative electrode sheet, and the separator are sequentially stacked, the number of stacking processes increases. Therefore, there are problems that the tact time of production is long and the productivity is not good. In view of this, for example, a technique has been devised in which the positive electrode sheet is stored in the bag-shaped separator in advance, thereby reducing the number of the above-described stacking steps and improving battery productivity (see Patent Document 1 and the like).

JP 2003-92100 A

  By the way, in this type of separator, there is a need to use a separator whose surface is coated with a predetermined material (for example, ceramics) for the purpose of improving durability against heat shrinkage, for example. However, in the case of the bag-like separator described in the background art, when the surface-coated separator is bonded to the bag-like shape, there is a possibility that the coating member may have an effect and the front and back separators may not be firmly fixed. It was.

  An object of the present invention is to provide an electrode storage separator and a power storage device that can firmly fix a pair of separators in a state in which electrodes are stored therein even when a separator coated with ceramics is used.

  In order to solve the above problems, in the invention according to claim 1, in an electrode storage separator that includes a pair of opposing separators and sandwiches an electrode between the pair of separators, the separator includes a porous resin base material, A ceramic layer provided on at least one surface of the porous resin substrate, and the porous resin substrate has a heat-resistant layer and a thermal melting having a shutdown function and a lower melting point than the heat-resistant layer. The hot melt layer exposed on at least one of the two opposing surfaces of the pair of separators is welded to the other opposing surface.

  According to the configuration of the present invention, since a part of the separator coated with ceramics is provided with a heat melting layer not coated with ceramics, even if a pair of separators sandwiching the electrodes are both coated with ceramics, It is possible to join the separator with a hot melt layer. For this reason, in the electrode storage separator that stores the electrode inside, even if the separator is coated with ceramics in order to improve durability against heat shrinkage, the separator is fixed with the electrode body sandwiched between the pair of separators. It becomes possible. Further, since the heat melting layer having a low melting point is used as the bonding surface, the separator can be fused at a low temperature. Therefore, it becomes possible to make wrinkles less likely to occur during fusion.

  The invention according to claim 2 is summarized in that, in the invention according to claim 1, the porous resin base material has the heat-resistant layer on both surfaces of the hot-melt layer. According to this configuration, since a plurality of heat-resistant layers are provided, the heat resistance of the separator can be improved.

  The invention according to claim 3 is summarized in that, in the invention according to claim 1 or 2, the hot-melt layer is made of porous polyethylene, and the heat-resistant layer is made of porous polypropylene. According to this configuration, since the melting point of porous polyethylene is about 130 ° C., the separator can be joined at the lowest possible temperature. Therefore, problems such as stacking deviation due to the shrinkage of the separator and short circuit due to the lack of the hot melt layer of the separator hardly occur.

  The invention according to claim 4 is summarized in that, in the invention according to any one of claims 1 to 3, the porous resin base material has the ceramic layers on both sides. According to this configuration, since the ceramic layer extends over a plurality of surfaces, the effect is high in ensuring durability against heat shrinkage.

  The invention according to claim 5 is summarized in that, in the invention according to any one of claims 1 to 4, the electrode is a positive electrode. According to this configuration, for example, the outer dimension of the electrode storage separator and the outer dimension of the negative electrode can be matched, so that the electrode storage separator and the negative electrode are alternately stacked when the electrode body is assembled. It becomes easy to align the position.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the pair of separators are formed by bending a single sheet and a second sheet surface. It is composed of a sheet surface, and one of the positive electrode and the negative electrode is accommodated between the sheet surfaces, and the hot melt layer exposed at the edge of the first sheet surface and the second sheet surface is joined. To do. According to this configuration, the separator having a shape that can accommodate the electrode therein is formed by bending one sheet, so that the separator can be easily manufactured in a required shape.

  The gist of the invention described in claim 7 is that the electrode storage separator according to any one of claims 1 to 6 is provided.

  According to the present invention, even when a ceramic-coated separator is used, the pair of separators can be firmly fixed in a state where the electrodes are housed therein.

The disassembled perspective view which shows the structure of the secondary battery of 1st Embodiment. The perspective view which shows the external appearance of a secondary battery. The disassembled perspective view which shows the structure of an electrode body. Sectional drawing which shows the location where the lead was welded in the current collection part. Sectional drawing of an electrode storage bag-shaped separator. Sectional drawing which shows the layer structure of a separator sheet. The top view of an electrode storage bag-shaped separator. Explanatory drawing which shows the state which set the positive electrode sheet to the separator sheet base material. Explanatory drawing which shows the state by which the separator sheet base material in which the positive electrode sheet was set was welded. Explanatory drawing which shows the state which cut | disconnects the separator sheet base material after welding. The perspective view of the electrode storage bag-shaped separator before closing in the bag shape of 2nd Embodiment. Explanatory drawing which shows the manufacture example of the electrode storage bag-shaped separator of another example.

(First embodiment)
Hereinafter, a first embodiment of an electrode storage separator and a power storage device embodying the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the secondary battery 2 as the power storage device is mounted on a vehicle 1 such as a hybrid vehicle (plug-in hybrid vehicle) or an EV vehicle, for example, and used as a drive source. Used as a power source (not shown). For example, a metal case 3 is provided in the secondary battery 2, and an electrode body 5, which is a power generation element, is accommodated inside the case body 4. The upper opening 4a of the case body 4 is sealed in a sealed state by a metal plate-like case lid 6.

  As shown in FIG. 2, a positive electrode terminal 7 that is an electrode terminal for a positive electrode and a negative electrode terminal 8 that is an electrode terminal for a negative electrode are provided on the upper surface of the secondary battery 2. The positive terminal 7 and the negative terminal 8 are exposed to the outside of the case 3 through the opening hole 6 a of the case lid 6. Ring-shaped insulating members 9 that insulate the positive terminal 7 and the negative terminal 8 from the case 3 are attached between the positive terminal 7 and the negative terminal 8 and the case 3.

  As shown in FIG. 3, the electrode body 5 includes a bag-like separator (hereinafter referred to as an electrode-containing bag-like separator 10) in which an electrode (positive electrode) is housed in a bag, and a thin negative electrode sheet 11 that serves as a negative electrode. An assembly having a plurality of layers. The electrode storage bag-shaped separator 10 is a member in which a thin positive electrode sheet 13 serving as a positive electrode is stored in a bag-shaped separator body 12. The electrode body 5 has a stacked structure in which the electrode storage bag-shaped separator 10 and the negative electrode sheet 11 are stacked in a certain direction along the thickness direction of the electrode body 5 (stacking direction: Y-axis direction in FIG. 1 and the like). The negative electrode sheet 11 and the positive electrode sheet 13 constitute an electrode.

  The positive electrode sheet 13 is provided with a metal sheet-like foil 14, and the positive electrode active material layer 15 is applied to both sides of the foil 14, so that this portion constitutes a coating portion 16. A part of the foil 14 protrudes as a tab on a part of the periphery of the positive electrode sheet 13, and this part constitutes an uncoated part 17 where the positive electrode active material layer 15 is not applied. The negative electrode sheet 11 is also provided with a metal sheet-like foil 18, and a negative electrode active material layer 19 is applied to both surfaces of the foil 18, and the coated part 20 and the uncoated part 21 are configured in the same manner as the positive electrode sheet 13. Has been.

  As shown in FIG. 1, each of the positive electrode sheet 13 and the negative electrode sheet 11 has leads 24 and 25 in current collecting portions 22 and 23 in which uncoated portions 17 and 21 having the same polarity are bundled in the stacking direction Y. Are welded to each other. As shown in FIG. 4, the leads 24 and 25 are fixed to the current collectors 22 and 23, with the vicinity of the roots of the current collectors 22 and 23 being welded portions 26 and 27. Further, the positive terminal 7 is connected to the positive lead 24 and the negative terminal 8 is connected to the negative lead 25. The current collectors 22 and 23 protrude upward from the upper surface of the electrode pair 28 which is the main body of the electrode body 5, and are positioned closer to the ends on the side away from each other in the width direction of the electrode pair 28 (X-axis direction in FIG. 1). Is arranged.

  As shown in FIGS. 3 and 5, the electrode storage bag-shaped separator 10 includes two separator sheets 29 each having a quadrangular shape as a pair of separators so as to face each other, and one end of the separator sheet 29 (the upper side of the paper surface). 29a) and the lower end (the lower side 29b of the paper surface) are welded to form a bag. Thereby, the storage part 30 (refer FIG. 5) which consists of clearance gaps is provided in the inside of the electrode storage bag-shaped separator 10, and the positive electrode sheet 13 is stored in this storage part 30. FIG. The separator sheet 29 is a sheet member that insulates the positive electrode sheet 13 and the negative electrode sheet 11.

  As shown in FIG. 6, the separator sheet 29 includes a porous resin base material 36 and an insulating ceramic layer 37 formed on at least the first surface (one surface). Incidentally, FIG. 6 illustrates a sheet having a ceramic layer 37, that is, an outer ceramic layer 37a and an inner ceramic layer 37b on both surfaces of the porous resin base material 36. The ceramic layer 37 includes, for example, an inorganic filler and a binder. Thus, the electrode storage bag-like separator 10 of this example becomes a ceramic separator by being coated with ceramics on both sides, and has high durability against heat shrinkage.

  The porous resin substrate 36 includes a porous polyethylene layer (hereinafter referred to as PE layer) 38 as an inner layer that functions as a heat-melting layer and a pair of porous polypropylene layers (hereinafter referred to as PP) as an outer layer that functions as a heat-resistant layer. Layer) 39. The PP layer 39 includes two layers, an outer PP layer 39a and an inner PP layer 39b. The PE layer 38 has a shutdown function and has a melting point of about 130 ° C. The PP layers 39a and 39b have a function of a heat-resistant layer and have a melting point of about 160 to 170 ° C. Separator sheet 29 of this example is composed of five layers of outer ceramic layer 37a / outer PP layer 39a / PE layer 38 / inner PP layer 39b / inner ceramic layer 37b from the sheet surface side.

  In addition, for example, the ceramic layer 37 is not provided on the upper side 29a and the lower side 29b of each separator sheet 29 on the inner side (positive electrode sheet 13 side) of the separator sheet 29 and corresponding to the peripheral edge of the electrode, thereby providing a PE layer. An exposed portion 32 in which a part of 38 is exposed to the outside is provided. The exposed portion 32 of this example is formed only on one inner surface of one separator sheet 29.

  As shown in FIG. 5, the exposed portion 32 has an exposed portion 32 formed on the upper side 29a as an upper end exposed portion 32a and an exposed portion 32 formed on the lower side 29b as a lower end exposed portion 32b. The upper end side exposed portion 32a and the lower end side exposed portion 32b are formed in the entire region in the width direction (X-axis direction in FIG. 3) of the electrode storage bag-shaped separator 10. Although the pair of separator sheets 29 is a ceramic coat, the exposed portions 32a and 32b can be welded. The exposed portion 32 is provided so that the entire positive electrode active material layer 15 faces the inner ceramic layer 37b.

  As shown in FIG. 7, the pair of separator sheets 29 is welded to the entire length direction (X-axis direction in FIG. 7) of the exposed portions 32 a and 32 b, so that this portion becomes a welded portion 33 and has a bag shape. It is fixed and attached to. The welding method (welding portion 33) may be either intermittent welding or continuous welding. In the case of this example, the welded portion 33 formed on the upper end exposed portion 32a is referred to as an upper welded portion 33a, and the welded portion 33 formed on the lower end exposed portion 32b is referred to as a lower welded portion 33b. In addition, the welding part 33 (33a, 33b) comprises a junction part.

  The positive electrode sheet 13 is positioned in the vertical direction (Z-axis direction in FIG. 7) in the storage unit 30 by being sandwiched from above and below by the upper welded portion 33a and the lower welded portion 33b. Further, the uncoated portion 17 of the positive electrode sheet 13 has a pair of welded portions (electrode positioning welded portions) 33c that are part of the upper welded portion 33a at the base portion, and is disposed in the vicinity of the paper surface in the storage portion 30. They are positioned in the left-right direction (X-axis direction in FIG. 7: tab surface direction). In addition, the electrode positioning welding part 33c comprises a junction part.

Next, the manufacturing process of the electrode storage bag-like separator 10 of this example will be described with reference to FIGS.
As shown in FIG. 8, in the separator manufacturing process, a pair of long strip-like separator sheet base materials 34 whose surfaces are ceramic-coated are prepared. Exposed portions 32a and 32b from which the PE layer 38 is exposed are formed on the upper and lower ends of the inner surface of the separator sheet base material 34, respectively. A plurality of positive electrode sheets 13 are arranged side by side between a pair of separator sheet base materials 34, and these positive electrode sheets 13 are sandwiched and set by a pair of separator sheet base materials 34.

  Subsequently, as shown in FIG. 9, the pair of separator sheet base materials 34 are welded at the upper end side exposed portion 32 a and the lower end side exposed portion 32 b, so that the positive electrode sheet 13 is separated into two separator sheet base materials. It is wrapped in 34 and integrated (unitized). That is, a pair of strip-shaped separator sheet base material 34 and a plurality of positive electrode sheets 13 are assembled as a strip-shaped separator unit 35. Thereby, the separator sheet base material 34 is formed in a bag shape, and the positive electrode sheet 13 is stored in the internal storage portion 30. At the time of welding, the left and right sides of the positive electrode sheet 13 are sandwiched between the electrode positioning welds 33c, thereby positioning the positive electrode sheet 13 in the left-right direction (X-axis direction in FIG. 9).

  Then, as shown in FIG. 10, one strip-shaped separator unit 35 is cut between the adjacent positive electrode sheets 13 to form each electrode-containing bag-shaped separator 10. Various cutting methods such as punching and cutting can be used. Thus, a plurality of electrode storage bag-shaped separators 10 are formed from one strip-shaped separator unit 35.

  Subsequently, in the stacking step, the electrode storage bag-shaped separator 10 and the negative electrode sheet 11 are alternately stacked. Then, after overlapping the required number, uncoated portions 17 and 21 having the same polarity are bundled together, the leads 24 and 25 are welded, and the electrode body 5 is assembled. After the electrode body 5 is assembled, the secondary battery 2 is assembled by housing the electrode body 5 in the case body 4 and closing the opening 4 a of the case body 4 with the case lid 6.

  As described above, in this example, in the two ceramic-coated separator sheets 29, the exposed portions 32a and 32b are provided on the upper side 29a and the lower side 29b, respectively, and the exposed portions 32a and 32b are welded. Is formed into a bag shape. Therefore, even if the separator sheet 29 whose surface is coated with ceramics is used to improve durability against heat shrinkage, the separator sheet 29 can be firmly fixed in a bag shape by a simple method called welding. It becomes.

According to the configuration of the present embodiment, the following effects can be obtained.
(1) Even if the separator sheet 29 is a ceramic separator with the aim of improving durability against heat shrinkage during use, exposed portions 32a and 32b in which the upper side 29a and the lower side 29b of the front and back separator sheet 29 are not coated with ceramics Therefore, the two separator sheets 29 can be welded in a bag shape at the exposed portions 32a and 32b. Therefore, even if the separator sheet 29 is a ceramic separator, it can be firmly closed in a bag shape with the positive electrode sheet 13 accommodated therein.

  (2) The exposed portion 32 is a portion formed by exposing the PE layer 38 having a lower melting point than, for example, polypropylene (PP). Therefore, it becomes possible to weld the separator sheet with a low melting point, so that the separator sheet 29 can be hardly wrinkled at the time of fusion.

  (3) Since the PP layers 39a and 39b are provided on both sides of the PE layer 38, a plurality of heat-resistant layers are provided on one separator sheet 29, so that the heat resistance of the electrode housing bag-like separator 10 can be improved.

  (4) Since the PE layer 38 having a lower melting point than the PP layers 39a and 39b is used as the exposed portion 32, the pair of separator sheets 29 can be fixed in a bag shape at the lowest possible temperature. Therefore, it is possible to make it difficult to cause problems such as a stacking shift due to the shrinkage of the separator and a short circuit due to a lack of the hot melt layer of the separator.

  (5) The ceramic layers 37 were provided on both the front and back surfaces of the separator sheet 29. Therefore, since as many ceramic layers 37 as possible exist in one electrode storage bag-shaped separator 10, the effect of ensuring durability against thermal shrinkage is enhanced.

  (6) By enclosing the positive electrode sheet 13 in advance with two separator sheets 29, these are placed as one component called the electrode storage bag-shaped separator 10, and the electrode storage bag-shaped separator 10 and the negative electrode sheet 11 are alternately stacked. Thus, the electrode body 5 is assembled. For this reason, when assembling the electrode body 5, the number of stacked sheets imposed in the stacking process can be reduced, and the tact time of production is shortened. Therefore, the productivity of the electrode body 5 and thus the secondary battery 2 can be improved.

  (7) The positive electrode (positive electrode sheet 13) of the positive and negative electrodes is stored in the electrode storage bag-shaped separator 10. By the way, in this kind of electrode body 5, it is necessary to form a negative electrode larger than a positive electrode on the relationship of the exchange of the ion between electrodes. For this reason, if the positive electrode is stored inside the electrode storage bag-shaped separator 10 as in this example, as a result, the outer dimension of the electrode storage bag-shaped separator 10 and the outer dimension of the negative electrode sheet 11 are the same. It can take the dimension to do. Therefore, when the electrode body 5 is assembled, alignment when the electrode storage bag separator 10 and the negative electrode sheet 11 are alternately stacked is facilitated. In addition, the stacked electrode storage bag-shaped separator 10 and the negative electrode sheet 11 are not easily displaced in the electrode body 5.

  (8) The exposed portions 32a and 32b are provided on the upper side 29a and the lower side 29b in the ceramic-coated separator sheet 29. Therefore, after setting the positive electrode sheet 13 between the front and back separator sheets 29, the front and back separator sheets 29 are welded at two sides to form a bag shape, and this is cut between adjacent positive electrode sheets 13. The electrode storage bag-shaped separator 10 can be manufactured by a simple process.

  (9) The exposed portions 32a and 32b were formed over the entire upper side 29a and lower side 29b of the separator sheet 29. For this reason, since it becomes possible to take the welding surface of the separator sheet 29 widely, the separator sheet 29 of the front and back can be attached and fixed more firmly.

  (10) When the two separator sheets 29 are welded at the exposed portions 32a and 32b, the electrode positioning welded portion 33c is formed so as to sandwich the base of the uncoated portion 17 of the positive electrode sheet 13 from both sides. For this reason, since the uncoated portion 17 of the positive electrode sheet 13 is positioned in the left-right direction on the paper surface by the electrode positioning welded portion 33c, the positive electrode sheet 13 can be hardly displaced in the left-right direction on the paper surface in the storage unit 30.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. In addition, this example is an example which changed the layer structure of the separator 10 of 1st Embodiment, The other basic structure is the same as that of 1st Embodiment. Therefore, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and only different parts are described in detail.

  As shown in FIG. 11, the electrode storage bag-shaped separator 10 of this example includes a first sheet surface 29x and a second sheet surface 29y as a pair of separators formed by bending one separator sheet 29 in the middle. The two sheets are stacked to form a bag shape, and the positive electrode sheet 13 is accommodated therein. The exposed portion 32 is formed over the entire edge portion of the separator sheet 29. For this reason, the two separator sheets 29 are formed in a bag shape by heat-sealing (heat-welding) the exposed portions 32 on three sides around the positive electrode sheet 13.

  In the case of this example, inside the separator sheet 29, the inner ceramic layer 37b and the inner PP layer 39b are omitted to provide an exposed portion 32 in which a PE layer having a melting point lower than PP or the like is exposed to the outside. Then, the separator sheet 29 folded in two is fixed to the exposed portions 32 by heat fusion, so that the separator sheet 29 is formed into a bag shape. For this reason, since it becomes possible to heat-seal the separator sheet 29 at low temperature, it becomes possible to make it difficult to produce a wrinkle in the separator sheet 29 at the time of heat-sealing.

According to the configuration of the present embodiment, the following effects can be obtained in addition to (1) to (10) described in the first embodiment.
(11) Since one separator sheet 29 is folded into two to form a bag, the separator sheet 29 can be easily processed into a bag.

Note that the embodiment is not limited to the configuration described so far, and may be modified as follows.
-In each embodiment, as shown in FIG. 12, after preparing the one large separator sheet 41 and arranging the some positive electrode sheet 13 in this, the separator sheet 41 is folded in the center, The positive electrode sheet 13 May be wrapped with a separator sheet 41 from the front and back. In this case, a plurality of electrode storage bag-shaped separators 10 can be manufactured in a simple form in which one separator sheet 41 is bent.

  In the first embodiment, the exposed portions 32a and 32b are not limited to being formed over the entire upper side 29a (lower side 29b), and may be partially formed, for example. In the second embodiment, the exposed portion 32 is not limited to being formed in the entire area around the sheet, and may be formed only in part.

In each embodiment, the exposed portions 32a and 32b may be formed on the left side or the right side of the sheet of the separator sheet 29, for example.
-In each embodiment, the magnitude | size (area) of the exposure part 32 (32a, 32b) can be changed suitably.

-In 1st Embodiment, the upper end side exposed part 32a and the lower end side exposed part 32b may take different length.
In each embodiment, at least one of the exposed portions 32 (32a, 32b) may be sufficient. For example, you may have only either the upper end side exposed part 32a or the lower end side exposed part 32b.

In each embodiment, the ceramic separator may be a ceramic-coated sheet, for example (sheet single side) only.
In each embodiment, the direction when the positive electrode sheet 13 is arranged on the separator sheet 29 may be a direction in which the positive electrode sheet 13 is rotated about 90 degrees in the left direction (counterclockwise) in FIG.

  In each embodiment, the electrode storage bag-shaped separator 10 is manufactured by setting a plurality of positive electrode sheets 13 on one long strip-shaped separator sheet base material 34 and cutting them in units of the positive electrode sheet 13. It is not limited. For example, it may be manufactured by using separator sheets 29 and 29 previously cut to a final size, setting the positive electrode sheet 13 on the separator sheets 29 and welding the peripheral edge thereof.

In each embodiment, the positive electrode terminal 7 and the negative electrode terminal 8 are not limited to being arranged on the same side of the electrode pair 28, and may be arranged on different sides.
-In each embodiment, the arrangement position of the current collection parts 22 and 23 can be changed not only to the upper surface of the electrode pair 28 but to a side surface or a lower surface.

  -In each embodiment, the positive electrode current collection part 22 is not limited to one, For example, multiple may be sufficient and these may be electrically connected by one or a some lead | read | reed. The same can be said for the negative electrode current collector 23.

-In each embodiment, a positive electrode and a negative electrode are not limited to a sheet-like member, For example, you may use the plate-shaped member with predetermined amount thickness.
-In each embodiment, the raw material of the positive electrode sheet 13, the negative electrode sheet 11, and the separator sheet 29 can be changed suitably.

  In each embodiment, the porous resin substrate 36 is not limited to three layers of the outer PP layer 39a / PE layer 38 / inner PP layer 39b, and may be four or more layers. Further, the porous resin substrate 36 may have two layers each having a PE layer 38 and a PP layer 39.

In each embodiment, the heat resistant layer may be made of a material other than polypropylene (PP), and the molten layer may be made of a material other than polyethylene (PE).
-In each embodiment, the structure of the positive electrode terminal 7, the negative electrode terminal 8, and the current collection parts 22 and 23 is not restricted to the example described in embodiment, It can change into another structure.

In each embodiment, the opening 4 a of the case body 4 is not limited to being formed on the upper surface of the case body 4, and can be changed to another location such as a side surface of the case body 4.
-In each embodiment, the electrode body 5 is not limited to a laminated structure, It is good also as a winding structure which winds a sheet-like electrode pair in many layers, and has a positive / negative electrode layer.

-In each embodiment, an electrical storage apparatus is not limited to a secondary battery, For example, it is good also as an electrical storage charged / discharged with an electric double layer capacitor.
-In each embodiment, the electrode in the electrode storage bag-shaped separator 10 is not limited to a positive electrode, It is good also as a negative electrode.

  In each embodiment, various types of welding such as spot welding, butt welding, and projection welding can be used for lead welding (resistance welding). Further, the welding is not limited to resistance welding, and other methods can be adopted.

-In each embodiment, an electrode storage separator is not limited to bag shape, For example, it can change into other shapes, such as a cylinder shape.
In each embodiment, the separator shape is not limited to a square shape, and can be appropriately changed to various shapes.

In each embodiment, the separator sheet 29 only needs to have the exposed portion 32 formed on at least one of the two opposing surfaces.
In each embodiment, the electrode body 5 (secondary battery 2) is not limited to being mounted on the vehicle 1, and can be mounted on other devices and apparatuses.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Secondary battery as an electrical storage apparatus, 5 ... Electrode body, 10 ... Electrode storage bag-shaped separator as an electrode storage separator, 11 ... Negative electrode sheet which comprises an electrode, 13 ... Positive electrode sheet which comprises an electrode, 17 ... Uncoated part as a tab, 29 ... Separator sheet, 29a ... Upper side, 29b ... Lower side, 29x ... First sheet surface, 29y ... Second sheet surface, 32 (32a, 32b) ... Exposed part, 33 (33a) 33b, 33c) ... welded part as a joint part, 36 ... porous resin base material, 37 (37a, 37b) ... ceramics (ceramic layer), 38 ... porous polyethylene layer (PE layer) as a hot melt layer, 39 (39a, 39b): porous polypropylene layer (PP layer) as a heat-resistant layer, X axis: width direction of the separator, Z axis: direction intersecting the width direction of the separator.

Claims (7)

In an electrode storage separator comprising a pair of opposing separators and sandwiching an electrode between the pair of separators,
The separator has a porous resin base material and a ceramic layer provided on at least one surface of the porous resin base material, and the porous resin base material has a heat resistant layer and a shutdown function. A heat-melting layer having a lower melting point than the heat-resistant layer,
An electrode storage separator, wherein the hot melt layer exposed on at least one of the two opposing surfaces of the pair of separators is welded to the other opposing surface. The electrode storage separator according to claim 1, wherein the porous resin base material has the heat-resistant layer on both surfaces of the hot-melt layer. The electrode housing separator according to claim 1 or 2, wherein the heat-melt layer is made of porous polyethylene, and the heat-resistant layer is made of porous polypropylene. The said porous resin base material has the said ceramic layer on both surfaces, The electrode storage separator as described in any one of Claims 1-3 characterized by the above-mentioned. The electrode storage separator according to any one of claims 1 to 4, wherein the electrode is a positive electrode. The pair of separators includes a first sheet surface and a second sheet surface formed by bending one sheet, and accommodates one of a positive electrode and a negative electrode between the sheet surfaces, and the first sheet surface and The electrode storage separator according to any one of claims 1 to 5, wherein the hot melt layer exposed at an edge portion of the second sheet surface is welded. A power storage device comprising the electrode storage separator according to claim 1.