JP6233060B2 - Terminal film for power storage device and power storage device - Google Patents

Description

  The present invention relates to a terminal film for an electricity storage device and an electricity storage device, in particular, a packaging material for packaging an electricity storage device body, a metal terminal that is electrically connected to the electricity storage device body and extends outside the packaging material, The present invention relates to a terminal film for an electricity storage device and an electricity storage device interposed therebetween.

  In recent years, there has been an increasing demand for miniaturization of portable devices and effective use of natural energy, and research and development of lithium-ion secondary batteries (one of storage devices) with higher voltage and higher energy density has been conducted. It has been broken.

  As a packaging material used for the lithium ion secondary battery, metal cans have been used in the past, but because of the low manufacturing cost in response to demands for thinner and diversified products to be applied, A packaging material in which a laminated body obtained by laminating a metal layer (for example, an aluminum foil) and a resin film is formed into a bag shape is often used.

  The lithium ion secondary battery includes a battery body, a packaging material that wraps the battery body, a metal terminal (tab lead) that is connected to the negative electrode or the positive electrode of the battery body, and extends to the outside of the packaging material. And a terminal film for an electricity storage device (also referred to as “tab sealant”) covering each of the outer peripheral side surfaces.

  A part of the terminal film for an electricity storage device is covered with a packaging material, and the remaining part is exposed from the packaging material. The terminal film for an electricity storage device is bonded to a metal terminal by performing a fusion treatment.

  The terminal film for an electricity storage device is a film for insulating a metal layer and a metal terminal constituting the packaging material. For this reason, in addition to the adhesiveness with the packaging material and the metal terminal, the terminal film for the electricity storage device has sufficient insulation after the heat sealing process (in other words, it can have sufficient insulation). It is desirable that the thickness be

In addition, if the color of the terminal film for the electricity storage device is transparent, it is determined whether or not the terminal film for the electricity storage device is present when performing an inspection to determine whether the terminal film for the electricity storage device is interposed between the packaging material and the metal terminal. Becomes difficult.
Furthermore, when the color of the terminal film for the electricity storage device is transparent, it is difficult to accurately determine the attachment position of the terminal film for the electricity storage device when performing the inspection of the position of the terminal film for the electricity storage device relative to the metal terminal. turn into.

  Patent Document 1 discloses a terminal film for an electricity storage device (lead wire film) in which polypropylene graft-deformed with an unsaturated carboxylic acid or polyethylene graft-deformed with an unsaturated carboxylic acid is laminated in three layers.

  Patent Document 1 discloses a terminal film for a power storage device (lead wire film) in order to accurately determine whether or not a power storage device terminal film is interposed between the packaging material and the metal terminal. Coloring with pigments or dyes is disclosed.

  Further, in Patent Document 1, as a pigment for coloring the terminal film for an electricity storage device, inorganic pigments such as calcium carbonate, anhydrous silica, alumina, cobalt blue and other extender pigments, titanium dioxide, zinc oxide and other white pigments, Use black pigments such as iron black and graphite, organic pigments such as insoluble azo pigments, azo pigments such as azo lake pigments, phthalocyanine pigments such as copper phthalocyanine and metal-free phthalocyanine lakes, anthraquinone pigments, and thioindigo pigments The use of synthetic polycyclic pigments, other nitroso pigments, daylight fluorescent pigments, and the like is disclosed.

JP 2003-123710 A

When the terminal film for electrical storage devices is colored using the pigment disclosed in Patent Document 1, it is difficult to color with a deep color.
For this reason, for example, when the width of the metal terminal is narrow (for example, 3 mm or less) and the width of the terminal film for the electricity storage device is also narrow (for example, 5 mm or less), the attachment position of the electricity storage device terminal film is accurately determined. It was difficult.

  Therefore, in order to solve the above-mentioned problem, the inventor of the present invention has developed a conductive film in an insulating layer constituting an intermediate layer located between two outermost layers in a terminal film for an electricity storage device in which three or more insulating layers are laminated. By adding carbon black or graphite (hereinafter referred to as “conductive pigment”), which is a pigment, the intermediate layer is colored black, leading to the idea of improving the visibility compared to the prior art.

  And as a result of intensive studies, the inventor found that when the terminal film for an electricity storage device having an intermediate layer colored with the conductive pigment was disposed so as to cover the outer peripheral side surface of the metal terminal, the conductive pigment In order to ensure the insulation between the conductive intermediate layer and the metal terminal, heat sealing treatment for fusing the terminal film for the electricity storage device and the metal terminal (applying a predetermined temperature and pressure) After the process of fusing), it came to the idea that it is important that the thickness of the outermost layer disposed between the intermediate layer and the metal terminal is not too thin.

  Accordingly, the present invention provides a power storage device by coloring the intermediate layer with a dark color by adding carbon black, graphite or the like as a conductive pigment to the insulating layer constituting the intermediate layer disposed between the two outermost layers. Terminal film for power storage device capable of improving the inspection accuracy of the terminal film for power storage and ensuring sufficient insulation between the metal terminal to which the terminal film for power storage device is fused and the intermediate layer And it aims at providing an electrical storage device.

In order to solve the above problems, the terminal film for an electricity storage device according to one embodiment of the present invention is disposed so as to cover a part of the outer peripheral surface of the metal terminal that is electrically connected to the electricity storage device body constituting the electricity storage device. A storage device terminal film comprising: a first outermost layer including a first insulating layer; a second outermost layer including a second insulating layer; the first outermost layer; and the second outermost layer. A third insulating layer disposed between the first insulating layer and the outer layer; and an intermediate layer that is added to the third insulating layer and includes a conductive pigment that can be colored in black. The first and second layers An insulating filler is added to at least one of the insulating layers, and the content of the conductive pigment contained in the intermediate layer is 0.01 wt% or more and 3.00 wt% or less .

According to the present invention, by adding a conductive pigment that can be colored black to the third insulating layer, it is possible to color the intermediate layer with a dark shade (specifically, black).
Thereby, since the visibility of the terminal film for electrical storage devices is improved, the inspection of the terminal film for electrical storage devices (for example, the inspection whether the electrical storage device terminal film is attached to the metal terminal, the electrical storage device terminal with respect to the metal terminal) The accuracy of the inspection of the attachment position of the film can be improved.
In particular, it is effective when the width of the metal terminal is narrow and the width of the terminal film for an electricity storage device is narrow.

In addition, by adding an insulating filler to at least one of the first and second insulating layers, heat sealing treatment (a predetermined temperature and pressure is applied to melt the metal terminal and the outermost layer). It is possible to allow the insulating filler to function as a spacer for ensuring the thickness of the outermost layer to which the insulating filler has been added.
Thereby, by arranging the terminal film for the electricity storage device so that the outermost layer to which the insulating filler is added and the metal terminal are in contact with each other, the conductive intermediate layer and the metal terminal by containing the conductive pigment It is possible to ensure sufficient insulation between the two.

  In addition, when the two outermost layers contain an insulating filler, the outermost layer disposed between the metal layer and the intermediate layer constituting the packaging material can improve the insulation between the metal layer and the intermediate layer. Can do.

  That is, according to the present invention, by adding a conductive pigment to the insulating layer constituting the intermediate layer disposed between the two outermost layers and coloring the intermediate layer with a dark shade (black), the terminal for the electricity storage device The inspection accuracy of the film can be improved, and insulation between the metal terminal to which the terminal film for an electricity storage device is fused and the intermediate layer can be sufficiently secured.

  In the terminal film for an electricity storage device according to one embodiment of the present invention, an insulating filler may be added to only one of the first and second insulating layers.

  Thus, even when the insulating filler is added to only one of the first and second insulating layers, the inspection accuracy of the power storage device terminal film can be improved, and the power storage device terminal The insulation between the metal terminal to which the film is fused and the intermediate layer can be sufficiently secured.

If the content (concentration) of the conductive pigment contained in the intermediate layer is less than 0.01 wt%, it will be difficult to color the intermediate layer with a dark hue. In addition, if the content of the conductive pigment added to the third insulating layer is more than 3.00 wt%, the conductivity of the intermediate layer becomes too high, so that an electrical connection between the intermediate layer and the metal terminal is caused. It will be difficult to ensure sufficient insulation.
Therefore, by setting the content (concentration) of the conductive pigment added to the third insulating layer to 0.01 wt% or more and 3.00 wt% or less, the visibility of the terminal film for an electricity storage device can be improved and the electrical Sufficient insulation can be ensured.

  Moreover, in the terminal film for an electricity storage device according to one embodiment of the present invention, the average particle size of the insulating filler is 1/30 to 1/2 of the thickness of the insulating layer to which the insulating filler is added. It may be a double value.

  Thus, by setting the average particle size of the insulating filler to a value that is 1/30 to 1/2 times the thickness of the insulating layer to which the insulating filler is added, the outermost layer (insulating filler) with respect to the metal terminal Insulating fillers can function satisfactorily as spacers without lowering the fusibility of the outermost layer.

  Moreover, in the terminal film for an electricity storage device according to one embodiment of the present invention, the content (concentration) of the insulating filler may be not less than 0.1 wt% and not more than 20 wt%.

If the content of the insulating filler added to the insulating layer is less than 0.1 wt%, the content of the insulating filler is too small (because the insulating filler does not function as a spacer). The thickness of the outermost layer including the insulating filler becomes too thin.
Therefore, it becomes difficult to insulate between the intermediate layer and the metal terminal by the outermost layer disposed between the intermediate layer and the metal terminal.

In addition, if the content of the insulating filler added to the insulating layer is more than 20 wt%, the proportion of the insulating layer is reduced, so that the fusion between the outermost layer containing the insulating filler and the metal terminal (in other words, In this case, the adhesiveness is reduced.
Therefore, the fusion property between the outermost layer to which the insulating filler is added and the metal terminal is lowered by setting the content of the insulating filler added to the insulating layer to 0.1 wt% or more and 20 wt% or less. In addition, it is possible to insulate between the conductive intermediate layer and the metal terminal.

  In the terminal film for an electricity storage device according to one embodiment of the present invention, the insulating filler may have a spherical shape.

  Thus, since the shape of the insulating filler is spherical, it is possible to improve the function of the insulating filler as a spacer as compared with the case where an amorphous filler is used as the insulating filler. After the heat sealing treatment, the thickness of the outermost layer containing the insulating filler can be increased.

  Further, in the terminal film for an electricity storage device according to one aspect of the present invention, a fourth film is provided between the intermediate layer and the first outermost layer and between the intermediate layer and the second outermost layer. An insulating layer may be provided.

  Thus, the intermediate layer and the packaging material are configured by disposing the fourth insulating layer between the intermediate layer and the first outermost layer and between the intermediate layer and the second outermost layer, respectively. The insulation between the metal layer and the insulation between the intermediate layer and the metal terminal can be improved.

  In order to solve the above-described problem, an electricity storage device according to one embodiment of the present invention is the electricity storage device terminal film according to any one of claims 1 to 7, an electricity storage device body to be charged and discharged, and the electricity storage device. A pair of the metal terminals that are electrically connected to the main body and partially covered with the power storage device terminal film; a part of the power storage device terminal film; and a packaging material that covers the power storage device main body. It is characterized by that.

  According to this invention, the inspection precision of the terminal film for electrical storage devices can be improved because the terminal film for electrical storage devices of any one of Claims 1 thru | or 7 covers a part of metal terminal. At the same time, sufficient insulation can be secured between the metal terminal to which the terminal film for an electricity storage device is fused and the intermediate layer.

  Further, in the electricity storage device according to one aspect of the present invention, of the first and second outermost layers, one outermost layer is disposed so as to cover a part of the outer peripheral surface of the metal terminal, and the other outermost layer is disposed. The outermost layer may be disposed in contact with the packaging material, and the one outermost layer may include the insulating filler.

  As described above, the outermost layer disposed so as to cover a part of the outer peripheral surface of the metal terminal includes an insulating filler, so that the terminal film for the electricity storage device is bonded between the metal terminal and the intermediate layer. It is possible to sufficiently secure the insulation property.

  According to the terminal film for an electricity storage device of the present invention, the electrical insulation between the intermediate layer containing the conductive pigment that can improve the inspection accuracy of the terminal film for the electricity storage device and can be colored black and the metal terminal Can be secured sufficiently.

It is a perspective view which shows schematic structure of the electrical storage device which concerns on embodiment of this invention. It is sectional drawing which shows an example of the cut surface of the packaging material shown in FIG. It is sectional drawing of the AA line direction of the terminal film for electrical storage devices shown in FIG. 1, and a metal terminal.

  Embodiments to which the present invention is applied will be described below in detail with reference to the drawings. The drawings used in the following description are for explaining the configuration of the embodiment of the present invention. The size, thickness, dimensions, and the like of each part shown in the drawings are the actual terminal film for an electricity storage device and the electricity storage device. It may be different from the dimensional relationship.

(Embodiment)
FIG. 1 is a perspective view showing a schematic configuration of an electricity storage device according to an embodiment of the present invention. In FIG. 1, as an example of the electricity storage device 10, a lithium ion secondary battery is illustrated as an example, and the following description is given.
Note that the lithium ion secondary battery configured as shown in FIG. 1 is sometimes called a battery pack or a battery cell.

  Referring to FIG. 1, an electricity storage device 10 according to the present embodiment is a lithium ion secondary battery, and may be called an electricity storage device body 11, a packaging material 13, and a pair of metal terminals 14 (“tab leads”). ) And a terminal film 16 for an electricity storage device (sometimes referred to as “tab sealant”).

  The power storage device body 11 is a battery body that performs charging and discharging. The packaging material 13 is disposed so as to cover the surface of the electricity storage device body 11 and to be in contact with a part of the electricity storage device terminal film 16.

  2 is a cross-sectional view showing an example of a cut surface of the packaging material shown in FIG. 2, the same components as those in the structure shown in FIG.

Here, an example of the configuration of the packaging material 13 will be described with reference to FIG.
The packaging material 13 includes an inner layer 21, an inner-side adhesive layer 22, a corrosion prevention treatment layer 23-1, a barrier layer 24 that is a metal layer, and a corrosion prevention treatment layer 23 from the inside contacting the power storage device body 11. -2, outer layer side adhesive layer 25, and outer layer 26 are sequentially laminated.

As a base material of the inner layer 21, for example, an acid-modified polyolefin resin obtained by graft-modifying maleic anhydride or the like on a polyolefin resin or a polyolefin resin can be used.
Examples of the polyolefin resin include low density, medium density, and high density polyethylene; ethylene-α olefin copolymer; homo, block, or random polypropylene; propylene-α olefin copolymer. These polyolefin resins may be used individually by 1 type, and may use 2 or more types together.

Further, the inner layer 21 may be configured by using a single layer film or a multilayer film in which a plurality of layers are laminated according to a required function. Specifically, for example, in order to impart moisture resistance, a multilayer film in which a resin such as an ethylene-cyclic olefin copolymer or polymethylpentene is interposed may be used.
Furthermore, the inner layer 21 may contain various additives, for example, a flame retardant, a slip agent, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and the like.

The thickness of the inner layer 21 is preferably set within a range of 10 to 150 μm, for example, but more preferably 30 to 80 μm. If the thickness of the inner layer 21 is less than 10 μm, the heat seal adhesion between the packaging materials 13 and the adhesion with the terminal film 16 for an electricity storage device may be reduced.
Moreover, since it will become a factor of the cost increase of the packaging material 13 when the thickness of the inner layer 21 is thicker than 150 micrometers, it is unpreferable.

As the inner layer side adhesive layer 22, for example, a known adhesive such as a general dry lamination adhesive or an acid-modified heat-fusible resin can be appropriately selected and used.
As shown in FIG. 2, the corrosion prevention treatment layers 23-1 and 23-2 are preferably formed on both surfaces of the barrier layer 24 in terms of performance. However, considering the cost, the inner side adhesive layer 22 side is provided. You may arrange | position the corrosion prevention process layer 23-1 only to the surface of the barrier layer 24 located.

The barrier layer 24 is a conductive metal layer. Examples of the material of the barrier layer 24 include aluminum and stainless steel, but aluminum is preferable from the viewpoint of cost, weight (density), and the like.
As the outer layer side adhesive layer 25, for example, a polyurethane-based general adhesive mainly composed of polyester polyol, polyether polyol, acrylic polyol or the like can be used.

As the outer layer 26, for example, a single film such as nylon or polyethylene terephthalate (PET), or a multilayer film can be used.
The outer layer 26 may contain various additives such as a flame retardant, a slip agent, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and the like, like the inner layer 21.
Further, the outer layer 26 may have a protective layer formed by laminating a resin insoluble in the electrolytic solution or coating a resin component insoluble in the electrolytic solution as a countermeasure against liquid leakage, for example. .

  FIG. 3 is a cross-sectional view of the electricity storage device terminal film and metal terminal shown in FIG. In FIG. 3, the same components as those in the structure shown in FIG.

Referring to FIGS. 1 and 3, the pair (two in FIG. 1) of metal terminals 14 includes a metal terminal body 14-1 and a corrosion prevention layer 14-2.
Of the pair of metal terminal bodies 14-1, one metal terminal body 14-1 is electrically connected to the positive electrode of the electricity storage device body 11, and the other metal terminal body 14-1 is connected to the electricity storage device body 11. Is electrically connected to the negative electrode.
The pair of metal terminal bodies 14-1 extends in a direction away from the electricity storage device body 11, and part of the metal terminal bodies 14-1 is exposed from the packaging material 13. The shape of the pair of metal terminal bodies 14-1 can be, for example, a flat plate shape.

  A metal can be used as the material of the metal terminal body 14-1. The metal used as the material of the metal terminal body 14-1 is preferably determined in consideration of the structure of the electricity storage device body 11, the material of each component of the electricity storage device body 11, and the like.

For example, when the electricity storage device 10 is a lithium ion secondary battery, aluminum is used as the positive electrode current collector, and copper is used as the negative electrode current collector.
In this case, it is preferable to use aluminum as the material of the metal terminal body 14-1 connected to the positive electrode of the electricity storage device body 11. In consideration of corrosion resistance to the electrolyte, it is preferable to use, for example, an aluminum material having a purity of 97% or higher such as 1N30 as the material of the metal terminal body 14-1.

Furthermore, when bending the metal terminal body 14-1, it is preferable to use an O material tempered by sufficient annealing for the purpose of adding flexibility.
As a material of the metal terminal body 14-1 connected to the negative electrode of the electricity storage device body 11, it is preferable to use copper having a nickel plating layer formed on the surface or nickel.

  The thickness of the metal terminal body 14-1 depends on the size and capacity of the lithium ion secondary battery. When the lithium ion secondary battery is small, the thickness of the metal terminal body 14-1 is preferably 50 μm or more, for example. Moreover, in the case of a large-sized lithium ion secondary battery for power storage and in-vehicle use, the thickness of the metal terminal body 14-1 can be set as appropriate within a range of 100 to 500 μm, for example.

The corrosion prevention layer 14-2 is disposed so as to cover the surface of the metal terminal body 14-1. In the case of a lithium ion secondary battery, a corrosive component such as LiPF ₆ is included in the electrolytic solution.
The corrosion prevention layer 14-2 is a layer for suppressing the metal terminal body 14-1 from being corroded by a corrosive component such as LiPF ₆ contained in the electrolytic solution.

  The power storage device terminal film 16 is disposed so as to cover a part of the outer peripheral surface of the metal terminal 14. The power storage device terminal film 16 includes a first outermost layer 31 that contacts the outer peripheral side surface of the metal terminal 14, a second outermost layer 32 that contacts the packaging material 13, a first outermost layer 31, and a second outermost layer. The intermediate layer 33 disposed between the outer layer 32 and the outer layer 32 is laminated.

The first outermost layer 31 is disposed so as to cover one surface of the intermediate layer 33 having conductivity by including the conductive pigment 42 that can be colored black. The first outermost layer 31 includes a first insulating layer 35 that is an insulating resin layer and an insulating filler 36.
The first insulating layer 35 (in other words, the first outermost layer 31) is disposed so as to cover a part of the outer peripheral surface of the metal terminal 14.
The first outermost layer 31 is disposed so as to cover the outer peripheral surface of the metal terminal 14, thereby sealing the circumferential direction of the metal terminal 14 and bringing the power storage device terminal film 16 and the metal terminal 14 into close contact with each other. It has a function.

Therefore, as a material constituting the first insulating layer 35, for example, a resin having excellent adhesiveness may be used. As the resin material constituting the first insulating layer 35, for example, an acid-modified polyolefin resin obtained by graft-modifying maleic anhydride or the like on a polyolefin resin can be used.
The thickness of the 1st insulating layer 35 can be 10-50 micrometers, for example.

The insulating filler 36 is added to the first insulating layer 35. The insulating filler 36 has a thickness of the first outermost layer 31 after the heat sealing process (after a process of applying a predetermined temperature and pressure to fuse the packaging material 13 and the second outermost layer 32). It functions as a spacer for securing.
As the insulating filler 36, for example, a filler made of a metal oxide (for example, alumina or silica), a filler made of an organic material (for example, polycarbonate or epoxy resin), or the like can be used.

As the shape of the insulating filler 36, for example, an indeterminate shape or a spherical shape can be used, but a spherical shape is preferable.
Thus, by making the shape of the insulating filler 36 spherical, the function of the insulating filler 36 as a spacer can be improved. Thereby, the thickness of the 1st outermost layer 31 can be made thicker than the case where an amorphous filler is used after a heat sheet process. Therefore, the first outermost layer 31 can electrically insulate the intermediate layer 33 including the conductive pigment 42 from the metal terminal 14.

The particle size of the insulating filler 36 may be set to a value that is 1/30 to 1/2 times the thickness of the first insulating layer 35, for example.
As described above, by setting the particle size of the insulating filler 36 to a value 1/30 to 1/2 times the thickness of the first insulating layer 35, the first outermost layer 31 is fused to the metal terminal 14. The insulating filler 36 can be made to function as a spacer without lowering the properties.

The content (concentration) of the insulating filler 36 added to the first insulating layer 35 is preferably 0.1 wt% or more and 20 wt% or less, for example.
When the content of the insulating filler 36 added to the first insulating layer 35 is less than 0.1 wt%, the content of the insulating filler 36 is too small. When the terminal 14 and the first outermost layer 31 are fused (when heat-sealed), the thickness of the first outermost layer 31 becomes too thin.
Therefore, it is difficult to insulate between the conductive intermediate layer 33 and the metal terminal 14 by the first outermost layer 31.

On the other hand, when the content of the insulating filler 36 added to the first insulating layer 35 is more than 20 wt%, the ratio of the first insulating layer 35 decreases, and therefore the first outermost layer 31 and the metal terminal 14 are reduced. The adhesiveness (in other words, adhesiveness) between the two decreases.
Therefore, by making the content of the insulating filler 36 added to the first insulating layer 35 0.1 wt% or more and 20 wt% or less, the fusion property between the first outermost layer 31 and the metal terminal 14 can be improved. Without lowering, it is possible to electrically insulate between the conductive intermediate layer 33 and the metal terminal 14.

The second outermost layer 32 is disposed so as to cover the other surface of the intermediate layer 33 having conductivity by including the conductive pigment 42. The second outermost layer 32 includes a second insulating layer 38 that is an insulating resin layer, and an insulating filler 39.
The second insulating layer 38 (in other words, the second outermost layer 32) is brought into contact with the packaging material 13 by being fused with the packaging material 13 (specifically, the inner layer 21 shown in FIG. 2). Yes.

The second insulating layer 38 is fused to the packaging material 13 to seal the inside of the packaging material 13, and the storage device terminal film 16 and the packaging material 13 (specifically, the inner layer shown in FIG. 2). 21).
Therefore, from the viewpoint of adhesion to the packaging material 13, it is preferable to use a resin (for example, polyolefin resin) of the same system as the resin that is the base material of the inner layer 21 as the second insulating layer 38.
The thickness of the second insulating layer 38 can be set to 10 to 50 μm, for example.

The insulating filler 39 is added to the second insulating layer 38. The insulating filler 39 serves as a spacer for securing the thickness of the second outermost layer 32 when the packaging material 13 and the second outermost layer 32 are fused by applying a predetermined temperature and pressure. Function.
As the insulating filler 39, for example, a filler made of a metal oxide (for example, alumina or silica), a filler made of an organic material (for example, polycarbonate, epoxy resin, or the like) can be used.

Further, as the insulating fillers 36 and 39, for example, fillers of the same type and the same shape may be used.
In this way, by using fillers of the same type and the same shape as the insulating fillers 36 and 39, the preparation of the insulating fillers 36 and 39 is facilitated as compared with the case of preparing two different types of fillers. It can be carried out.

  As the insulating fillers 36 and 39, for example, fillers having different particle diameters (sizes) may be used. Thus, the thickness of the 1st and 2nd outermost layers 31 and 32 can be adjusted according to the objective by using the insulating filler made into a different shape as the insulating fillers 36 and 39. .

As the shape of the insulating filler 39, for example, an indeterminate shape or a spherical shape can be used, but a spherical shape is preferable.
Thus, by making the shape of the insulating filler 39 spherical, the function of the insulating filler 39 as a spacer can be improved. Thereby, after fuse | melting the packaging material 13 and the 2nd outermost layer 32 by applying a predetermined pressure and temperature (in other words, after a heat sheet process), compared with the case where an amorphous filler is used. The thickness of the second outermost layer 32 can be increased.
Therefore, the second outermost layer 32 can electrically insulate the intermediate layer 33 including the conductive pigment 42 from the barrier layer 24 constituting the packaging material 13.

The particle size of the insulating filler 39 may be, for example, a value that is 1/30 to 1/2 times the thickness of the second insulating layer 38.
In this manner, the second outermost layer 32 is fused to the packaging material 13 by setting the particle size of the insulating filler 39 to a value that is 1/30 to 1/2 times the thickness of the second insulating layer 38. The insulating filler 39 can be made to function sufficiently as a spacer without lowering the properties.

In addition, the content (concentration) of the insulating filler 39 added to the second insulating layer 38 is preferably 0.1 wt% or more and 20 wt% or less, for example.
When the content of the insulating filler 39 added to the second insulating layer 38 is less than 0.1 wt%, the content of the insulating filler 38 is too small. When the outermost layer 32 is fused, the thickness of the second outermost layer 32 may be reduced.

On the other hand, when the content of the insulating filler 39 added to the second insulating layer 38 is more than 20 wt%, the ratio of the second insulating layer 38 decreases, and therefore the second outermost layer 32 and the packaging material 13 are reduced. There is a risk that the fusing property (in other words, adhesion) between the two will decrease.
Therefore, by making the content of the insulating filler 39 added to the second insulating layer 38 0.1 wt% or more and 20 wt% or less, the fusion property between the second outermost layer 32 and the packaging material 13 is achieved. The electrical insulation between the conductive intermediate layer 33 and the barrier layer 24 can be sufficiently ensured without lowering.

The intermediate layer 33 is disposed between the first outermost layer 31 and the second outermost layer 32. The intermediate layer 33 has one surface covered with the first outermost layer 31 and the other surface covered with the second outermost layer 32.
The intermediate layer 33 includes a third insulating layer 41 that is an insulating resin layer disposed between the first outermost layer 31 and the second outermost layer 32, and a conductive material that functions as a colorant that can be colored black. The pigment 42 is included.

As a material of the third insulating layer 41, it is preferable to use a resin material having a high melting point that hardly melts during the heat sheet processing. Specifically, as the material of the third insulating layer 41, for example, polyolefin may be used from the viewpoint of adhesion to the first and second outermost layers 31 and 32.
Further, when it is desired to improve the insulation of the intermediate layer 33, the material of the third insulating layer 41 may be, for example, polyester such as PET (Polyethylene terephthalate) or a heat resistant resin (for example, polycarbonate). Good.

The third insulating layer 41 constituting the intermediate layer 33 does not need to have a single layer structure, and may have a multilayer structure in which a plurality of polyester layers are bonded together with an adhesive, for example.
The thickness of the intermediate layer 33 (in other words, the thickness of the third insulating layer 41) can be appropriately set within a range of 10 to 200 μm, for example, and preferably 20 to 100 μm.
In the intermediate layer 33, the balance between the metal terminal 14 and the first outermost layer 31 is important, and when the first outermost layer 31 and the metal terminal 14 are thick, the thickness of the intermediate layer 33 is also increased. The thickness may be increased accordingly.

The conductive pigment 42 functions as a colorant that colors the intermediate layer 33 black by being added to the third insulating layer 41. As the conductive pigment 42, for example, carbon black or graphite can be used.
In this way, by having the intermediate layer 33 including the third insulating layer 41 that is an insulating resin layer and the conductive pigment 42 that can be colored black, the intermediate layer 33 has a dark color (specifically, black). The layer 33 can be colored.

This improves the visibility of the electricity storage device terminal film 16, so that the inspection of the electricity storage device terminal film 16 (specifically, for example, whether the electricity storage device terminal film 16 is attached to the metal terminal 14 or not). Inspection, inspection of the attachment position of the storage device terminal film 16 with respect to the metal terminal 14, etc.) can be performed with high accuracy. In particular, it is effective when the width of the metal terminal 14 is narrow and the width of the terminal film 16 for an electricity storage device is narrow.
The particle size of the conductive pigment 42 can be appropriately selected within a range of 1 nm to 1 μm, for example.

The content (concentration) of the conductive pigment 42 added to the third insulating layer 41 is preferably 0.01 wt% or more and 3.00 wt% or less, for example.
When the content of the conductive pigment 42 added to the third insulating layer 41 is less than 0.01 wt%, it becomes difficult to color the intermediate layer with a dark hue. In addition, if the content of the conductive pigment 42 added to the third insulating layer 41 is more than 3.00 wt%, the conductivity of the intermediate layer 33 becomes too high, so that the intermediate layer 33 and the metal terminal 14 are not electrically connected. It is difficult to ensure sufficient electrical insulation.

  Therefore, by making the content of the conductive pigment 42 added to the third insulating layer 0.01 wt% or more and 3.00 wt% or less, the visibility of the terminal film 16 for an electricity storage device can be improved, and electrical Insulation can be sufficiently secured.

  According to the terminal film for an electricity storage device of the present embodiment, added to the third insulating layer 41 and the third insulating layer 41 disposed between the first outermost layer 31 and the second outermost layer 32. By having the intermediate layer 33 including the conductive pigment 42 that has been made, the intermediate layer 33 can be colored with a dark shade (black).

Thereby, since the visibility of the terminal film 16 for electrical storage devices improves, the inspection of the terminal film 16 for electrical storage devices (for example, the inspection of whether the electrical storage device terminal film 16 is attached to the metal terminal 14, the metal terminal 14 And the like can be improved.
In particular, it is effective when the width of the metal terminal 14 is narrow and the width of the terminal film 16 for an electricity storage device is narrow.

Further, by having the first outermost layer 31 in which the insulating filler 36 is added to the first insulating layer 35, it is insulated as a spacer for securing the thickness of the first outermost layer 31 after the heat sealing process. It becomes possible to make the functional filler 36 function.
Thereby, the intermediate layer 33 and the metal terminal having conductivity by containing the conductive pigment 42 by disposing the terminal film 16 for the electricity storage device so that the first outermost layer 31 and the metal terminal 14 are in contact with each other. It is possible to ensure sufficient insulation between the two.

  Furthermore, by having the second outermost layer 32 with the insulating filler 39 added to the second insulating layer 38, it is possible to suppress the thickness of the second outermost layer 32 from being reduced after the heat sealing process. It becomes. Thereby, the insulation property between the barrier layer 24 (metal layer) and the intermediate layer 33 constituting the packaging material 13 can be improved by the second outermost layer 32.

  Moreover, the electrical storage device 10 of the present embodiment having the electrical storage device terminal film 16 can obtain the same effects as the electrical storage device terminal film 16.

  In the present embodiment, the case where the first and second outermost layers 31 and 32 include an insulating filler has been described as an example. However, in the case of the configuration shown in FIG. 3, only the first outermost layer 31 is used. May include an insulating filler (in this case, the insulating filler 36) (in other words, the second outermost layer 32 may not include the insulating filler 39).

  In this case, by adding the conductive pigment 42 to the third insulating layer 41 constituting the intermediate layer 33 and coloring the intermediate layer 33 with a dark color (black), the inspection accuracy of the storage device terminal film 16 is improved. In addition, the insulation between the metal terminal 14 and the intermediate layer 33 to which the power storage device terminal film 16 is fused can be sufficiently secured.

3 may be fused to the metal terminal 14 in a state where the two terminal films 16 for an electricity storage device shown in FIG. That is, you may arrange | position the two terminal films 16 for electrical storage devices so that the 2nd outermost layer 32 and the metal terminal 14 may contact.
In this case, an effect similar to that of the terminal film for an electricity storage device of the present embodiment described above can be obtained.

  Further, in this configuration (specifically, the configuration in which the second outermost layer 32 and the metal terminal 14 are in contact), an insulating filler (in this case, the insulating filler 39) is added only to the second outermost layer 32. (In other words, the first outermost layer 31 may not include the insulating filler 36).

  For example, the first insulating layer 35 constituting the first outermost layer 31 disposed so as to cover a part of the outer peripheral surface of the metal terminal 14 and the packaging material 13 for packaging the power storage device body 11 are contacted. Even when a resin material having different characteristics is used for the second insulating layer 38 constituting the second outermost layer 32 arranged, by adding an insulating filler only to the first insulating layer 36, The first outermost layer 31 and the second outermost layer 32 can be distinguished.

The terminal film for an electricity storage device having such a configuration is obtained by adding the conductive pigment 42 to the third insulating layer 41 constituting the intermediate layer 33 and coloring the intermediate layer 33 with a dark color (black). The inspection accuracy of the electricity storage device terminal film 16 can be improved, and insulation between the metal terminal 14 and the intermediate layer 33 to which the electricity storage device terminal film 16 is fused can be sufficiently secured.
As described above, in the present invention, an insulating filler may be added to at least one of the first and second insulating layers 35 and 38.

Next, with reference to FIG. 3, the manufacturing method of the terminal film 16 for electrical storage devices of this Embodiment is demonstrated easily.
There is no restriction | limiting in particular in the manufacturing method of the terminal film 16 for electrical storage devices. The power storage device terminal film 16 can be manufactured using, for example, an extrusion molding method such as a T-die method or a round die method, or an inflation molding method, and a multilayer inflation molding method is preferable.

Generally, as the material for the terminal film 16 for an electricity storage device, a material having a melt mass flow rate (hereinafter referred to as “MFR”) of 5 g / 10 min or less is often used. For this reason, when the T-die method is used, the film formation is not stable and the manufacture is often difficult.
On the other hand, the inflation molding method is suitable for the production of the terminal film 16 for an electricity storage device because the film can be stably formed even with the above-mentioned material (a material having an MFR value of 5 g / 10 min or less).

The base material of the first outermost layer 31 is an insulating material in which an insulating filler 36 is uniformly kneaded into a melted insulating resin to be the first insulating layer 35 so as to have a predetermined content. A filler-containing resin is prepared.
In addition, as a base material of the second outermost layer 32, an insulating filler 39 is uniformly kneaded into a melted insulating resin to be the second insulating layer 38 so as to have a predetermined content. An insulating filler-containing resin is prepared.
Further, as a base material of the intermediate layer 33, a conductive pigment in which a conductive pigment 42 is uniformly kneaded so as to have a predetermined content in a melted insulating resin to be the third insulating layer 41. Prepare the resin.
Then, the two kinds of insulating filler-containing resins and the conductive pigment-containing resin are supplied to the apparatus.

The extrusion temperature when producing the terminal film 16 for an electricity storage device is preferably in the range of 170 to 300 ° C, and more preferably 200 to 250 ° C, for example.
When the extrusion temperature is less than 170 ° C., the melt of the insulating resin becomes insufficient, and the melt viscosity becomes considerably large, so that the extrusion from the screw may be unstable.
On the other hand, when the extrusion temperature exceeds 300 ° C., oxidation and deterioration of the insulating resin become severe, so that the quality of the terminal film 16 for power storage device is deteriorated.

  The number of rotations of the screw, the blow ratio, the take-off speed, etc. can be appropriately set in consideration of the set film thickness. Moreover, the film thickness ratio of each layer of the terminal film 16 for electrical storage devices can be easily adjusted by changing the rotation speed of each screw.

  In addition, you may manufacture the terminal film 16 for electrical storage devices of this Embodiment using the method of laminating | stacking the insulating layers (insulating film) formed into a film by the dry lamination using an adhesive agent, or sandwich lamination.

Here, with reference to FIG. 3, the fusion process which adhere | attaches the terminal film 16 for electrical storage devices and the metal terminal 14 of this Embodiment is demonstrated.
In the fusing process, the first outermost layer 31 is melted by heating, and the first outermost layer 31 and the metal terminal 14 are simultaneously bonded by pressurization. Is heat-sealed.

  Moreover, in the said fusion | melting process, in order to acquire sufficient adhesiveness and sealing performance of the terminal film 16 for electrical storage devices and the metal terminal 14, insulating resin (1st insulating layer) which comprises the 1st outermost layer 31 35 base material) is heated to a temperature equal to or higher than the melting point.

  Specifically, for example, 140 to 170 ° C. can be used with the power storage device terminal film 16 as a heating temperature. Further, the treatment time (total time of heating time and pressurization time) needs to be determined in consideration of the peel strength and productivity. The processing time can be appropriately set within a range of 1 to 60 seconds, for example.

  In addition, when giving priority to the production tact of the terminal film 16 for electrical storage devices, heat fusion may be performed at a temperature exceeding 170 ° C. for a short pressurization time. In this case, for example, 170 to 200 ° C. can be used as the heating temperature, and 3 to 20 seconds can be used as the pressurizing time, for example.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and within the scope of the present invention described in the claims, Various modifications and changes are possible.

  For example, a fourth insulating layer (not shown) made of an insulating resin is disposed between the intermediate layer 33 and the first outermost layer 31 and between the intermediate layer 33 and the second outermost layer 32, respectively. May be.

  Thus, by disposing a fourth insulating layer (not shown) between the intermediate layer 33 and the first outermost layer 31 and between the intermediate layer 33 and the second outermost layer 32, respectively. Moreover, the insulation between the intermediate layer 33 and the barrier layer 24 (metal layer) constituting the packaging material 13 and the insulation between the intermediate layer 33 and the metal terminal 14 can be improved (FIGS. 1 to 1). 3).

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

Example 1
<Preparation of positive electrode tab and negative electrode tab>
Referring to FIG. 3, the positive electrode tab and the negative electrode tab of Example 1 (in other words, metal terminal 14 (also referred to as “tab lead”) and a pair of power storage device terminal films 16 (also referred to as “tab sealant”). A manufacturing method of the structure will be described.

  First, an aluminum thin plate member having a width of 5 mm, a length of 20 mm, and a thickness of 100 μm is prepared as the metal terminal main body 14-1 for the positive electrode. Next, non-chromium surface treatment is performed on the surface of the aluminum thin plate member to form a corrosion prevention layer 14-2 (non-chromium surface treatment layer), so that the aluminum thin plate member and the non-chromium-based member are formed. A positive-side metal terminal 14 including a surface treatment layer (hereinafter, referred to as “positive-electrode metal terminal 14A”) was produced.

  Next, a nickel thin plate member having a width of 5 mm, a length of 20 mm, and a thickness of 100 μm is prepared as the negative electrode metal terminal main body 14-1, and then non-chromium is applied to the surface of the nickel thin plate member. By carrying out the system surface treatment to form a corrosion prevention layer 14-2 (non-chromium-based surface treatment layer), the nickel-made thin plate member and the metal terminal 14 on the negative electrode side including the non-chromium-based surface treatment layer (hereinafter, For convenience of explanation, a “negative electrode metal terminal 14B” was prepared.

  Subsequently, spherical silica (insulating) having an average particle diameter of 10.0 μm so as to have a concentration (content) of 3.0 wt% with respect to the acid-modified polypropylene serving as a base material of the first insulating layer 35. The base material of the 1st outermost layer 31 was produced by adding and mixing the property filler 36).

Next, spherical silica (insulating) having an average particle diameter of 10.0 μm so as to have a concentration (content) of 3.0 wt% with respect to the acid-modified polypropylene which is the base material of the second insulating layer 38. The base material of the second outermost layer 32 was produced by adding and mixing the conductive filler 39).
Next, carbon black (conductive pigment 42) having an average particle diameter of 20 nm is added to the polypropylene serving as the base material of the intermediate layer 33 so that the concentration (content) is 0.1 wt%. By mixing, the base material of the intermediate layer 33 was produced.

Next, the base material of the first outermost layer 31, the base material of the second outermost layer 32, and the base material of the intermediate layer 33 are put into an inflation type film extrusion manufacturing apparatus (Co-OI type) manufactured by Sumitomo Heavy Industries Modern Co., Ltd. The laminated film (film serving as the base material of the power storage device terminal film 16) was prepared by setting and extruding the three base materials with the film extrusion manufacturing apparatus.
At this time, the laminated film was formed so that the thickness of the first insulating layer 35 was 30 μm, the thickness of the second insulating layer 38 was 30 μm, and the thickness of the third insulating layer 41 was 30 μm.
The melting temperature of the base material of the first outermost layer 31, the base material of the second outermost layer 32, and the base material of the intermediate layer 33 was 210 ° C. The blow ratio was set to 2.2.

Next, by cutting the laminated film, four power storage device terminal films 16 having a width of 9 mm and a length of 5 mm were produced.
Thereafter, the positive electrode metal terminal 14A is sandwiched between the two power storage device terminal films 16, and the two power storage device terminal films 16 are heated at a heating temperature of 155 ° C. for 10 seconds to obtain the positive metal terminal 14A. And two sheets of storage device terminal film 16 were heat-sealed to prepare a positive electrode tab including the positive electrode metal terminal 14 </ b> A and the two storage device terminal films 16.

  Next, the negative electrode metal terminal 14B and the two electric storage devices are bonded by heat-sealing the negative electrode metal terminal 14B and the two electric storage device terminal films 16 sandwiching the negative electrode metal terminal 14B in the same manner. A negative electrode tab made of the terminal film 16 was prepared.

<Preparation of battery pack for evaluation>
Next, a 25 μm thick nylon layer (outer layer 26), a 5 μm thick polyester polyol-based adhesive (outer layer side adhesive layer 25), and an aluminum foil (barrier layer 24) that is an A8079-O material having a thickness of 40 μm. A first corrosion prevention treatment layer (corrosion prevention treatment layer 23-1) formed by subjecting one surface of the aluminum foil to a non-chromium surface treatment, and a non-chromium surface treatment of the other surface of the aluminum foil. A second corrosion prevention treatment layer (corrosion prevention treatment layer 23-2) to be formed, a 30 μm thick acid-modified polypropylene layer (inner layer side adhesive layer 22), and a 40 μm thick polypropylene layer (inner layer 21) And a packaging material 13 having a rectangular shape with a size of 50 mm × 90 mm was prepared.

  Next, the packaging material 13 and the positive electrode are folded by folding at the midpoint of the long side of the packaging material 13 and sandwiching the positive electrode tab and the negative electrode tab on one of the two folded portions having a length of 45 mm. The tab for use and the tab for negative electrode were fused. At this time, the heat sealing conditions were a heating temperature of 190 ° C. and a treatment time of 5 seconds.

Thereafter, 2 mL of an electrolytic solution in which lithium hexafluorophosphate was added to a mixed solution of diethyl carbonate and ethylene carbonate was filled in the packaging material 13.
Next, the remaining side of the packaging material 13 was heat-sealed. The heat sealing conditions at this time were a heating temperature of 190 ° C. and a processing time of 3 seconds.
As a result, a battery pack capable of tab evaluation in which the power storage device main body 11 was not enclosed was produced.

(Example 2)
In Example 2, the laminated film (electric storage device) of Example 2 was prepared in the same manner as the laminated film of Example 1 except that spherical silica (insulating filler 36) was not added to the first insulating layer 35. Film to be a base material of the terminal film 16 for manufacturing).
Thereafter, an evaluation battery pack of Example 2 was produced in the same manner as in Example 1.

(Example 3)
In Example 3, the laminated film (electric storage device) of Example 3 was prepared in the same manner as the laminated film of Example 1 except that spherical silica (insulating filler 39) was not added to the second insulating layer 38. Film to be a base material of the terminal film 16 for manufacturing).
Thereafter, an evaluation battery pack of Example 3 was produced in the same manner as in Example 1.

Example 4
In Example 4, the same method as in the laminated film of Example 1 was used except that carbon black was added to the third insulating layer 41 so that the concentration (content) was 1.0 wt%. 4 laminated film (film which becomes a base material of the terminal film 16 for electrical storage devices) was produced.
Thereafter, an evaluation battery pack of Example 4 was produced in the same manner as in Example 1.

(Example 5)
In Example 5, the carbon black is added to the third insulating layer 41 and the spherical silica is added to the first and second insulating layers 35 and 38 so that the concentration (content) is 0.01 wt%. The same as the laminated film of Example 1 except that the average particle size of (insulating fillers 36, 39) was changed to 3.0 μm and the content of insulating fillers 36, 39 was changed to 1.0 wt%. In this manner, a laminated film of Example 5 (a film serving as a base material of the terminal film 16 for an electricity storage device) was produced.
Thereafter, an evaluation battery pack of Example 5 was produced in the same manner as in Example 1.

(Example 6)
In Example 6, except that the average particle diameter of the spherical silica (insulating fillers 36 and 39) was changed to 3.0 μm, and the content of the insulating fillers 36 and 39 was changed to 20.0 wt%. A laminated film of Example 6 (a film serving as a base material of the electricity storage device terminal film 16) was produced in the same manner as the laminated film of Example 1.
Thereafter, an evaluation battery pack of Example 6 was produced in the same manner as in Example 1.

(Example 7)
In Example 7, in place of the spherical silica, amorphous alumina (insulating fillers 36 and 39) having an average particle diameter of 1.0 μm was used, and the contents of the insulating fillers 36 and 39 were changed to 1.0 wt%. Except for this, a laminated film of Example 7 (film serving as a base material of the terminal film 16 for an electricity storage device) was produced in the same manner as the laminated film of Example 1.
Thereafter, an evaluation battery pack of Example 7 was produced in the same manner as in Example 1.

(Example 8)
In Example 8, the average particle diameter of the spherical silica (insulating fillers 36 and 39) was 1.0 μm, and the content of the insulating fillers 36 and 39 was changed to 5.0 wt%. The laminated film of Example 8 (film that becomes the base material of the storage device terminal film 16) was produced in the same manner as for the laminated film 1.
Thereafter, an evaluation battery pack of Example 8 was produced in the same manner as in Example 1.

Example 9
In Example 9, a polypropylene layer (10 μm) was disposed between the intermediate layer 33 and the second outermost layer 32, and the thicknesses of the first and second insulating layers 35 and 38 were changed to 20 μm. Except for this, a laminated film of Example 9 (film serving as a base material for the terminal film 16 for an electricity storage device) was produced in the same manner as the laminated film of Example 1.
Thereafter, an evaluation battery pack of Example 9 was produced in the same manner as in Example 1.

(Example 10)
In Example 10, except that the concentration (content) of carbon black added to the third insulating layer 41 was 0.005 wt%, the same method as in the laminated film of Example 1 was used. A laminated film (film serving as a base material for a terminal film for an electricity storage device) was produced.
Thereafter, an evaluation battery pack of Example 10 was produced in the same manner as in Example 1.

(Example 11)
In Example 11, except that the concentration (content) of carbon black added to the third insulating layer 41 was 10.0 wt%, the same method as in the laminated film of Example 1 was used. A laminated film (film serving as a base material for a terminal film for an electricity storage device) was produced.
Thereafter, an evaluation battery pack of Example 11 was produced in the same manner as in Example 1.

Example 12
In Example 12, the laminated film (terminal for power storage device) of Example 12 was obtained in the same manner as the laminated film of Example 1 except that the thickness of the first and second insulating layers 35 and 38 was 15 μm. Film as a base material of the film) was prepared.
Thereafter, an evaluation battery pack of Example 12 was produced in the same manner as in Example 1.

(Example 13)
In Example 13, the average particle diameter of the spherical silica (insulating filler 36) added to the first insulating layer is 0.5 μm, and the concentration (content) of the spherical silica (insulating filler 36) is 0.05 wt%. In the same manner as the laminated film of Example 1 except that spherical silica (insulating filler 39) was not added to the second insulating layer, Film as a base material) was produced.
Thereafter, an evaluation battery pack of Example 13 was produced in the same manner as in Example 1.

(Example 14)
In Example 14, the average particle diameter of spherical silica (insulating fillers 36 and 39) added to the first and second insulating layers is 10.0 μm, and the concentration (contained) of spherical silica (insulating fillers 36 and 39) is A laminated film of Example 14 (a film serving as a base material for a terminal film for an electricity storage device) was produced in the same manner as the laminated film of Example 1 except that the amount was 40.0 wt%.
Thereafter, an evaluation battery pack of Example 14 was produced in the same manner as in Example 1.

(Comparative example)
In the comparative example, except that carbon black was not added to the third insulating layer 41, the laminated film of Comparative Example 1 (the base material of the terminal film for an electricity storage device) Film).
Thereafter, an evaluation battery pack of Comparative Example 1 was produced in the same manner as in Example 1.

<Evaluation of sensing properties of negative electrode tab and positive electrode tab of Examples 1 to 14 and negative electrode tab and positive electrode tab of Comparative Example>
First, 500 specimens of the evaluation battery pack of Example 1 were prepared, and then the negative electrode tab and the positive electrode tab detected by the detector using an imaging detector (CV-X100, manufactured by Keyence Corporation). The detection rate (sensing property) was obtained.
With respect to the detection rate, those having a detection rate of 95% or more were evaluated as ◎, those having a detection rate of less than 95% and 90% or more were evaluated as ○, and those having a detection rate of less than 90% were determined as ×.

Next, 500 specimens of the evaluation battery packs of Examples 2 to 14 and the evaluation battery pack of the comparative example were prepared, respectively, by the same method as the sensing evaluation test of the negative electrode tab and the positive electrode tab of Example 1, The sensing properties of the negative electrode tab and the positive electrode tab constituting the evaluation battery packs of Examples 2 to 14 and the comparative example were evaluated.
In Table 1, the evaluation result (determination result) of the sensing property of the negative electrode tab and the positive electrode tab in Examples 1 to 14, and the evaluation result (determination result) of the sensing property of the negative electrode tab and the positive electrode tab of the comparative example , Indicate.
Table 1 also shows the thickness of each layer constituting the laminated films of Examples 1 to 14 and the laminated film of the comparative example, the type and average particle size of the insulating filler, the concentration (content) of carbon black, and the like. Show.

<Evaluation of Insulation of Evaluation Battery Packs of Examples 1 to 14 and Evaluation Example Battery Packs of Comparative Examples>
First, 100 specimens of the evaluation battery pack of Example 1 were prepared, and then using the withstand voltage / insulation resistance tester, the negative electrode metal terminal 14B and the packaging material 13 constituting the evaluation battery pack of Example 1 were prepared. The insulation between was measured.
The insulation measurement was performed on the 100 specimens. At this time, the case where no short-circuit occurred was judged as ◎, the case where the number of short-circuited samples was less than 10 was marked as ◯, and the case where the number of short-circuited samples was confirmed as 10 or more was judged as x. did.

Next, 100 specimens of each of the evaluation battery packs of Examples 2 to 14 and the evaluation battery pack of the comparative example were prepared, and the insulating property was evaluated by the same method as the insulation evaluation test of the evaluation battery pack of Example 1. Evaluation was performed.
Table 1 shows the evaluation results (judgment results) of the insulation of the evaluation battery packs of Examples 1 to 14 and the evaluation battery pack of the comparative example.

<Evaluation of Adhesiveness of Evaluation Battery Packs of Examples 1 to 14 and Evaluation Example Battery Packs of Comparative Examples>
100 samples of each of the evaluation battery packs of Examples 1 to 14 and the evaluation battery pack of the comparative example were prepared, and then 100 samples for evaluation of Examples 1 to 14 in a room maintained at 80 ° C. The battery pack and the battery pack for evaluation of the comparative example were stored for 4 weeks, and the presence or absence of leakage of the enclosed electrolyte was confirmed.
In this evaluation, ◎ indicates that no liquid leakage was confirmed, ◯ indicates that the liquid leakage is less than 5 samples, and ◯ indicates that the liquid leakage is less than 5 samples.
Table 1 shows the evaluation results (determination results) of the adhesion of the evaluation battery packs of Examples 1 to 14 and the evaluation battery pack of the comparative example.

<Summary of evaluation results shown in Table 1>
Referring to Table 1, in Examples 1 to 14, good results (judgment result: ま た は or ○) were obtained in sensing properties, insulating properties, and adhesion. In Examples 1 to 6, 8, and 9, very good results (judgment results are ◎) were obtained in all of the sensing properties, insulating properties, and adhesion properties.
Moreover, from the results of Examples 1 to 14, it was confirmed that the shape of the insulating filler may be spherical or indefinite.

From the evaluation results of Examples 1 to 3, if spherical silica is contained in at least one of the first and second outermost layers 31 and 32, very good results in sensing properties, insulating properties, and adhesion properties. It was confirmed that
From the evaluation results of Examples 1 to 9, the average particle diameter of the insulating fillers 36 and 39 is 1 / th of the thickness of the first and second insulating layers 35 and 38 to which the insulating fillers 36 and 39 are added. It was confirmed that the sensing property, insulating property, and adhesion were improved by setting the value to 30 to 1/2.

From the evaluation results of Examples 1 to 9, it can be confirmed that when the content of the insulating fillers 36 and 39 is in the range of 1.0 to 20 wt%, the sensing property, the insulating property, and the adhesion are improved. It was.
Further, from the evaluation results of Examples 1 to 12 and the comparative example, the content of carbon black contained in the intermediate layer 33 is less than 0.01 wt% (specifically, the content of carbon black is 0.1%). 005 wt%), the sensing performance decreases (specifically, the sensing performance determination result becomes ◯), and when the content of carbon black contained in the intermediate layer 33 is 0.1 wt% or more, the sensing performance is reduced. It was confirmed that it improved.

  From the evaluation result of Example 14, when the particle diameter of the spherical silica is large (in this case, 10.0 μm), and the concentration of the insulating filler contained in the first and second insulating layers is high (in this case, 40 wt. %), It was found that the adhesion was reduced.

  The present invention relates to a power storage device terminal film interposed between a packaging material for packaging a power storage device body, and a metal terminal electrically connected to the power storage device body and extending to the outside of the packaging material, and Applicable to power storage devices.

  DESCRIPTION OF SYMBOLS 10 ... Electric storage device, 11 ... Electric storage device main body, 13 ... Packaging material, 14 ... Metal terminal, 14-1 ... Metal terminal main body, 14-2 ... Corrosion prevention layer, 16 ... Terminal film for electric storage device, 21 ... Inner layer, 22 ... inner layer side adhesive layer, 23-1, 23-2 ... corrosion prevention treatment layer, 24 ... barrier layer, 25 ... outer layer side adhesive layer, 26 ... outer layer, 31 ... first outermost layer, 32 ... second Outermost layer, 33 ... intermediate layer, 35 ... first insulating layer, 36,39 ... insulating filler, 38 ... second insulating layer, 41 ... third insulating layer, 42 ... conductive pigment

Claims (8)

An electricity storage device terminal film arranged to cover a part of the outer peripheral surface of a metal terminal electrically connected to an electricity storage device body constituting the electricity storage device,
A first outermost layer including a first insulating layer;
A second outermost layer including a second insulating layer;
A third insulating layer disposed between the first outermost layer and the second outermost layer; and an intermediate layer containing a conductive pigment which is added to the third insulating layer and can be colored black ,
Have
An insulating filler is added to at least one of the first and second insulating layers ,
The terminal film for an electricity storage device, wherein the content of the conductive pigment contained in the intermediate layer is 0.01 wt% or more and 3.00 wt% or less .   The terminal film for an electricity storage device according to claim 1, wherein an insulating filler is added to only one of the first and second insulating layers. The average particle diameter of the insulating filler, according to claim 1 or 2, characterized in that the thickness of 1 / 30-1 / 2 times the value of the insulating layer insulative filler is added Terminal film for electricity storage devices. The terminal film for an electricity storage device according to any one of claims 1 to 3 , wherein the content of the insulating filler is 0.1 wt% or more and 20 wt% or less. The terminal film for an electrical storage device according to any one of claims 1 to 4 , wherein the insulating filler has a spherical shape. Between the first outermost layer and the intermediate layer, and between the intermediate layer and the second outermost layer, each of claims 1 to 5, characterized in placing a fourth insulating layer Among these, the terminal film for electrical storage devices of any one of Claims. The terminal film for an electricity storage device according to any one of claims 1 to 6 ,
A power storage device body to be charged and discharged;
A pair of the metal terminals that are electrically connected to the power storage device body and partially covered with the terminal film for the power storage device,
A part of the terminal film for the electricity storage device, and a packaging material covering the electricity storage device body,
An electricity storage device comprising: Of the first and second outermost layers, one outermost layer is disposed so as to cover a part of the outer peripheral surface of the metal terminal, and the other outermost layer is disposed so as to contact the packaging material. ,
The electric storage device according to claim 7 , wherein the one outermost layer includes the insulating filler.

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