JP2022063685A - battery - Google Patents

Abstract

To provide a battery in which damage to a laminated exterior body due to a resin arranged on a side face of an electrode body can be suppressed.SOLUTION: A laminated exterior body 50 has a first side 51 and a second side 52 facing the first side, in plan view. The first side is an edge of a bent part where a laminated sheet 60 is bent, and the second side is an edge of a seal region X to seal an electrode body. The electrode body includes a first resin structure part having a resin layer A on a side face on a side of the first side and a resin layer B being arranged outside the resin layer A and having a Young's modulus smaller than that of the resin layer A, and also includes a second resin structure part having a resin layer C on a side face on a side of the second side. When, in plan view, W represents a width of the electrode body including the first resin structure part and the second resin structure part, W1 represents a width of the first resin structure part, and W2 represents a width of the second resin structure part, W1 and W2 are 0.03 W or less, respectively. In the first resin structure part, a thickness of the resin layer A is 20% or more and 60% or less with respect to a total thickness of the resin layer A and the resin layer B.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to batteries.

A laminated battery having an electrode body (an aggregate of a positive electrode layer, a separate layer, and a negative electrode layer) and a laminated exterior body is known. For example, Patent Document 1 discloses a laminated battery having a battery element, a laminated sheet, a tab, and a sealing member.

Japanese Unexamined Patent Publication No. 2004-134115

By arranging the resin on the side surface of the electrode body housed in the internal region of the laminated outer body, each member constituting the electrode body can be fixed (fixed) and the positional deviation can be suppressed. On the other hand, as a laminated exterior body, an exterior body that seals an electrode body by bending one laminated sheet and sandwiching the electrode body is known. Since the bent portion formed by bending the laminated sheet is formed in a region where the thickness of the laminated sheet is thin (a region where the thickness is reduced by embossing), for example, when the electrode body is vacuum-sealed, the resin is formed. Contact with the laminated exterior may damage the laminated exterior.

The present disclosure has been made in view of the above circumstances, and an object of the present invention is to provide a battery in which damage to the laminated exterior body due to the resin arranged on the side surface of the electrode body is suppressed.

In the present disclosure, the battery comprises an electrode body and a laminated outer body, and the laminated outer body has a first side and a second side facing the first side in a plan view. The first side is the end of the bent portion of the laminated sheet, the second side is the end of the sealing region for sealing the electrode body, and the electrode body is the end portion of the sealing region. The electrode is provided with a first resin structural portion having a resin layer A and a resin layer B arranged outside the resin layer A and having a younger ratio than that of the resin layer A on the side surface on the first side. The body is provided with a second resin structure portion having a resin layer C on the side surface on the second side side, and the width of the electrode body including the first resin structure portion and the second resin structure portion is set in a plan view. When W is defined, the width of the first resin structure portion is W ₁ , and the width of the second resin structure portion is W ₂ , W ₁ and W ₂ are 0.03 W or less, respectively, and are described above. In the first resin structure portion, a battery is provided in which the thickness of the resin layer A is 20% or more and 60% or less with respect to the total thickness of the resin layer A and the resin layer B.

According to the present disclosure, a first resin structural portion having a resin layer A and a resin layer B having a Young's modulus smaller than that of the resin layer A is provided on the side surface on the first side corresponding to the end portion of the bent portion. By providing it, it is possible to suppress damage to the laminated exterior body. Further, since the ratio of the width of the first resin structure portion and the ratio of the width of the second resin structure portion and the ratio of the thickness of the resin layer A are within a predetermined range, the volume is suppressed while suppressing the damage of the laminated exterior body. The energy density can be improved.

The battery in the present disclosure has an effect of suppressing damage to the laminated exterior body due to the resin arranged on the side surface of the electrode body.

It is a schematic plan view which illustrates the battery in this disclosure. It is a schematic plan view which illustrates the laminated exterior body in this disclosure. It is a schematic perspective view illustrating the battery and its constituent members in the present disclosure. It is a schematic sectional drawing illustrating the battery in this disclosure. It is a relationship diagram which shows the relationship between the resin layer A and the resin layer B. It is a schematic sectional drawing illustrating the battery in this disclosure. It is a schematic sectional drawing illustrating the battery in this disclosure. It is a schematic plan view and a schematic sectional view illustrating the electrode body in this disclosure. It is schematic cross-sectional view which illustrates the electrode body in this disclosure.

Hereinafter, the battery in the present disclosure will be described in detail with reference to the drawings. Each figure shown below is schematically shown, and the size and shape of each part are exaggerated as appropriate for easy understanding. Further, in each figure, hatching showing a cross section of the member is omitted as appropriate. Further, in the present specification, when expressing the mode of arranging another member with respect to a certain member, when simply expressing "above" or "below", unless otherwise specified, it comes into contact with a certain member. As such, it includes both the case of arranging another member directly above or directly below, and the case of arranging another member above or below one member via another member.

FIG. 1 is a schematic plan view illustrating the battery in the present disclosure. FIG. 1A shows the laminated outer body 50 with a solid line, FIG. 1B shows the laminated outer body 50 with a dotted line, and shows the electrode body E housed in the internal region I of the laminated outer body 50. In addition, in FIG. 1 and FIG. 3 described later, the description of the first resin structure part and the second resin structure part is omitted for convenience. The battery 100 shown in FIG. 1 includes an electrode body E and a laminated exterior body 50. The laminated exterior body 50 has a first side 51 and a second side 52 facing the first side 51 in a plan view. The first side 51 is the end of the bent portion where the laminated sheet is bent, and the second side 52 is the end of the seal region X for sealing the electrode body E.

FIG. 2 is a schematic plan view illustrating the laminated exterior body in the present disclosure. As shown in FIGS. 2A and 2B, the laminated outer body 50 uses a single laminated sheet 60 (double cup type laminated sheet) having two embossed portions 53 for accommodating the electrode body. It can be obtained by sandwiching the electrode body by bending the laminated sheet 60 along the bending shaft A1 and forming _a seal region X after vacuum encapsulation. The laminated exterior body 50 shown in FIG. 2B faces the first side 51, which is the end of the bent portion of the laminated sheet, and the second side, which is the end of the seal region X, facing the first side 51. It has a side 52 and. Since the bent portion is formed in a region where the thickness of the laminated sheet is thin (a region where the thickness is reduced by embossing), the laminated outer body is likely to be damaged at the first side 51.

FIG. 3 is a schematic perspective view illustrating the battery and its constituent members in the present disclosure. Specifically, FIG. 3A is a schematic perspective view of the battery shown in FIG. 1B, and FIG. 3B is a schematic perspective view showing the components of the battery shown in FIG. 3A. be. As shown in FIGS. 3A and 3B, in the battery 100, the first electrode body 10 and the second electrode body 20 are laminated along the thickness direction _DT via the insulating member 30. .. The first electrode body 10 has a negative electrode tab 11t (electrode tab P) and a positive electrode tab 15t (electrode tab Q). On the other hand, the second electrode body 20 has a positive electrode tab 25t (electrode tab R) and a negative electrode tab 21t (electrode tab S). The electrode tab P and the electrode tab R are connected by a connecting member 40 in the internal region of the laminated exterior body.

FIG. 4 is a schematic cross-sectional view illustrating the battery in the present disclosure, and specifically, is a cross-sectional view taken along the line AA in FIG. 1 (b). As shown in FIG. 4, the electrode bodies 10 and 20 are arranged on the side surface on the first side 51 side of the resin layer A (resin layer 71) and outside the resin layer A, respectively, and are younger than the resin layer A. A first resin structure portion _R1 having a resin layer B (resin layer 72) having a small modulus is provided. Further, the electrode bodies 10 and 20 each include a second resin structure portion _R2 having a resin layer C (resin layer 73) on the side surface on the second side 52 side. Further, the width of the electrode bodies 10 and 20 including the first resin structure portion R ₁ and the second resin structure portion R ₂ is set to W, the width of the first resin structure portion is set to W ₁ , and the width of the second resin structure portion R ₂ is set to W 1. When the width is W ₂ , W ₁ and W ₂ are equal to or less than a predetermined value with respect to W. Further, in the first resin structure portion _R1 , the thickness of the resin layer A (distance in the direction orthogonal to the battery thickness direction _DT ) is based on the total thickness of the resin layer A and the resin layer B. It is within the specified range.

According to the present disclosure, a first resin structural portion having a resin layer A and a resin layer B having a Young's modulus smaller than that of the resin layer A is provided on the side surface on the first side corresponding to the end portion of the bent portion. By providing it, it is possible to suppress damage to the laminated exterior body. Further, since the ratio of the width of the first resin structure portion and the ratio of the width of the second resin structure portion and the ratio of the thickness of the resin layer A are within a predetermined range, the volume is suppressed while suppressing the damage of the laminated exterior body. The energy density can be improved.

As described above, by arranging the resin on the side surface of the electrode body housed in the internal region of the laminated exterior body, each member constituting the electrode body can be fixed (fixed) and the positional deviation can be suppressed. can. On the other hand, as a laminated exterior body, an exterior body that seals an electrode body by bending one laminated sheet and sandwiching the electrode body is known. Since the bent portion formed by bending the laminated sheet is formed in a region where the thickness of the laminated sheet is thin (a region where the thickness is reduced by embossing), for example, when the electrode body is vacuum-sealed, the resin is formed. Contact with the laminated exterior may damage the laminated exterior. In addition to vacuum encapsulation, the resin may come into contact with the laminated outer body due to expansion and contraction of the electrode body due to charging and discharging, and expansion and contraction of the laminated outer body due to heat, and the laminated outer body may be damaged.

In order to suppress damage to the laminated exterior body due to the resin arranged on the side surface of the electrode body, the present inventor has come up with the idea of using the resin layer A and the resin layer B having different Young's modulus. That is, by arranging the resin layer B having a smaller Young's modulus on the outside of the resin layer A, the resin layer A mainly exerts the function of immobilizing the electrode body, and the resin layer B is mainly laminated. By demonstrating the protective function of the exterior body, damage to the laminated exterior body can be suppressed.

Further, the present inventor has a case where the resin layer A and the resin layer B having different young ratios are used, that is, when the first resin structure portion has both the resin layer A and the resin layer B, the thickness of the first resin structure portion is thick. It was found that the volume energy density of the battery tends to decrease as the volume increases. Therefore, when an attempt was made to reduce the thickness of the first resin structure portion, if the thickness of the resin layer A is relatively small, the immobilization function of the resin layer A is not sufficiently exhibited, and the resin layer B is not sufficiently exhibited. If the thickness of the resin layer B is too small, there is a trade-off that the protective function of the laminated exterior body by the resin layer B is not sufficiently exhibited.

Here, FIG. 5 is a correlation diagram showing the relationship between the immobilization function and the protection function when the first resin structure portion has both the resin layer A and the resin layer B. In FIG. 5, black circles show the relationship between the ratio of the thickness of the resin layer A and the total thickness for ensuring the immobilization function from the viewpoint of the immobilization function. On the other hand, the white circles show the relationship between the ratio of the thickness of the resin layer A and the total thickness for ensuring the protective function from the viewpoint of the protective function. As shown by the black circles in FIG. 5, if the ratio of the thickness of the resin layer A is too small, the resin layer B having a small Young's modulus needs to secure the immobilization function, so that the total thickness becomes large. On the contrary, as shown by the white circles, if the ratio of the thickness of the resin layer A is too large, the ratio of the thickness of the resin layer B having a small Young's modulus that exerts the protective function is small, so that the total thickness is large. (Increase the total thickness and exert the protective function by the resin layer B). On the other hand, in the present disclosure, since the ratio of the thickness of the resin layer A is within a predetermined range (20% or more and 60% or less), both the immobilization function and the protection function can be compatible in a well-balanced manner.

1. 1. Battery Configuration The battery in the present disclosure includes an electrode body and a laminated exterior body. Further, as shown in FIG. 1, the laminated exterior body 50 has a first side 51 and a second side 52 facing the first side 51 in a plan view. The first side 51 is an end portion of a bent portion obtained by bending a laminated sheet. As shown in FIG. 2, the bent portion is a portion formed in a region embossed on both sides, and in this region, for example, the thickness of the laminated sheet is the thinnest. Therefore, the bent portion is a portion where the laminated outer body is likely to be damaged. On the other hand, as shown in FIG. 1, the second side 52 is an end portion of the seal region X for sealing the electrode body E. The seal region X is located outside the internal region I of the laminated exterior body 50, and is formed by fusing the inner layers of the laminated sheets facing each other in the thickness direction.

As shown in FIG. 1, it is preferable that the first side 51 and the second side 52 are arranged so as to face each other in the lateral direction _DS of the battery. Further, it is preferable that the positive electrode terminal 110 and the negative electrode terminal 120 are arranged along the longitudinal direction _DL of the battery. In FIG. 1, the positive electrode terminal 110 and the negative electrode terminal 120 are arranged on the same side of the laminated exterior body 50. By arranging both terminals on the same side, the volumetric energy density can be improved. On the other hand, both terminals may be arranged on different opposite sides of the laminated exterior body. By arranging both terminals on different opposite sides, it is possible to suppress the occurrence of a short circuit.

Further, as shown in FIG. 4, the electrode bodies 10 and 20 are arranged on the side surface on the first side 51 side of the resin layer A (resin layer 71) and on the outside thereof (the side opposite to the electrode bodies 10 and 20). The resin layer B (resin layer 72) and the first resin structure portion _R1 having the resin layer B are provided. Further, the electrode bodies 10 and 20 are provided with a second resin structure portion _R2 having a resin layer C (resin layer 73) on the side surface on the second side 52 side. In the present disclosure, the width of the electrode body (electrode bodies 10, 20) including the first resin structure portion R ₁ and the second resin structure portion R ₂ is W, and the width of the first resin structure portion R ₁ is W ₁ . The width of the second resin structure portion R ₂ is W ₂ . W ₁ and W ₂ are usually 0.03 W or less. By setting W ₁ and W ₂ within the above range, it is possible to suppress a decrease in volume energy density.

The resin layer A in the _first resin structure portion R1 is a layer arranged on the side surface of the electrode body. By providing the resin layer A, it is possible to suppress the positional deviation of each member constituting the electrode body and to suppress a short circuit between the members. In particular, when the battery in the present disclosure is an all-solid-state battery, a large restraining pressure is usually applied in the thickness direction of the battery by a restraining jig. Even in such a case, by providing the resin layer A, it is possible to suppress the positional deviation and short circuit of each member constituting the electrode body. Further, when the battery includes a plurality of electrode bodies, it is preferable that the resin layer A is individually arranged for each electrode body. Examples of the resin used for the resin layer A include urethane acrylate resin, epoxy resin, and olefin resin. Further, the resin may be a thermoplastic resin or a curable resin (for example, a cured product of a thermosetting resin or an ultraviolet curable resin).

The resin layer B in the _first resin structure portion R1 is arranged on the outside of the resin layer A (on the side opposite to the electrode body) and has a Young's modulus lower than that of the resin layer A. By providing the resin layer B, damage to the laminated exterior body can be suppressed. When the Young's modulus of the resin layer _A is EA (MPa) and the Young's modulus of the resin layer _B is _EB (MPa), the value of EA / _EB is not particularly limited, but is, for example, 1.05 or more. Yes, it may be 1.5 or more, or it may be 2 or more. The resin used for the resin layer B is the same as the resin used for the resin layer A. Young's modulus can be adjusted, for example, by appropriately changing the type of resin, the type or ratio of the curing agent. Further, when the battery includes a plurality of electrode bodies, it is preferable that the resin layer B is continuously arranged so as to straddle the plurality of electrode bodies. Further, as shown in FIG. 4, it is preferable that the corner portion of the resin layer B has an R shape. This is because damage to the laminated exterior can be effectively suppressed. Further, the shape of the corner portion of the resin layer B may be the same as the shape of the embossed portion of the laminated exterior body.

Further, in the first resin structure portion, the thickness of the resin layer A is set to TA, and the total thickness of the resin layer _A and the resin layer B is set to _TA . The thickness of the resin layer means the thickness in the direction orthogonal to the thickness direction of the battery (thickness direction _DT in FIG. 4). _TA is usually 20% or more and may be 30% or more with respect to _TAB . This is because if TA is too small, the immobilization function of the resin layer _A is not sufficiently exerted, and it is necessary to increase _TAB in order to fully exert the immobilization function. On the other hand, _TA is usually 60% or less, and may be 50% or less with respect to _TAB . This is because if the _TA is too large, the protective function of the resin layer B is not sufficiently exerted, and it is necessary to increase the _TA in order to fully exert the protective function.

Further, FIG. 6 is a schematic cross-sectional view illustrating the battery in the present disclosure, and specifically, is a schematic cross-sectional view showing FIG. 6 in more detail. In FIG. 6, the first electrode body 10 is arranged in order from one surface of the negative electrode current collector 11 and the negative electrode current collector 11, the first negative electrode layer 12a, the first separate layer 13a, and the first positive electrode layer 14a. The second negative electrode layer 12b, the second separate layer 13b, the second positive electrode layer 14b, and the second positive electrode current collector 15b, which are arranged in order from the other surface of the first positive electrode current collector 15a and the negative electrode current collector 11. And have. On the other hand, in the second electrode body 20, the first negative electrode layer 22a, the first separate layer 23a, the first positive electrode layer 24a, and the first positive electrode layer 24a are arranged in order from one surface of the negative electrode current collector 21 and the negative electrode current collector 21. 1 Positive electrode current collector 25a, a second negative electrode layer 22b, a second separate layer 23b, a second positive electrode layer 24b, and a second positive electrode current collector 25b arranged in order from the other surface of the negative electrode current collector 21. Have. Further, an insulating member 30 is arranged between the second positive electrode current collector 15b in the first electrode body 10 and the first positive electrode current collector 25a in the second electrode body 20.

In FIG. 6, the resin layer _A (resin layer 71) is arranged so as to cover the end faces t1 of the negative electrode current collector 11, the negative electrode current collector 21, and the like. That is, the resin layer A is arranged so as to cover the ends of the largest member (negative electrode current collector 11 and negative electrode current collector 21 in FIG. 6) constituting the electrode body in the width direction of the battery. May be good. As a result, the entire electrode body can be fixed (fixed), and the positional deviation of each member constituting the electrode body can be effectively suppressed. Further, as shown in FIG. 6, the end portion t ₃ of the insulating member 30 is the end portion of the largest member constituting the electrode body in the width direction of the battery (in FIG. 6, the negative electrode current collector 11 and the negative electrode current collector). It is preferable that it protrudes more than the body 21). This is because a short circuit is less likely to occur.

Further, as shown in FIG. 4, the electrode bodies 10 and 20 are provided with a second resin structural portion having a resin layer C (resin layer 73) on the side surface on the second side 52 side. By providing the resin layer C, similarly to the resin layer A, it is possible to suppress the positional deviation of each member constituting the electrode body and suppress the short circuit between the members. The resin used for the resin layer C may be the same as or different from the resin used for the resin layer A. The thickness of the resin layer C may be the same as or different from the thickness of the resin layer A, but is the same as the resin layer A in consideration of the main function (immobilization function) of the resin layer C. It is preferable to have.

The second resin structure portion may have only the resin layer C as the resin layer, or may further have another resin layer. For example, as shown in FIG. 7, in addition to the resin layer C (resin layer 73), the second resin structure portion has a resin layer D (resin layer 74) having a Young's modulus smaller than that of the resin layer C on the outside thereof. You may have. By providing the resin layer D, it is possible to suppress damage to the laminated exterior body as in the case of the resin layer B. The resin used for the resin layer D may be the same as or different from the resin used for the resin layer B. The thickness of the resin layer D may be the same as or different from the thickness of the resin layer B, but the laminated sheet is not as thin as the bent portion on the seal region side of the embossed portion. , It may be smaller than the thickness of the resin layer B. For the same reason, the thickness of the second resin structure portion may be smaller than the thickness of the first resin structure portion. Further, in the present disclosure, the electrode body may have a resin layer similar to the resin layer A arranged on the side surfaces of the first side and the side orthogonal to the second side. When the electrode terminals are present, it is preferable that the resin layer is arranged so as to avoid the electrode terminals.

The battery in the present disclosure may be provided with an electrode body alone or a plurality of electrodes in the internal region of the laminated outer body. It is preferable that the plurality of electrode bodies are laminated in the thickness direction. The number of the plurality of electrode bodies may be 2 or 3 or more. On the other hand, the number of the plurality of electrode bodies is, for example, 100 or less. Further, the plurality of electrode bodies may be connected in parallel or may be connected in series. Further, the battery in the present disclosure may be provided with a plurality of insulating members, each of which may be arranged between adjacent electrode bodies.

A battery in which a plurality of electrode bodies are connected in series will be described with reference to FIG. 3 described above. As shown in FIG. 3, the first electrode body 10 has a negative electrode tab 11t (electrode tab P) and a positive electrode tab 15t (electrode tab Q). On the other hand, the second electrode body 20 has a positive electrode tab 25t (electrode tab R) and a negative electrode tab 21t (electrode tab S). Further, as shown in FIGS. 1 and 3, the electrode tab P and the electrode tab R are connected by a connecting member 40 in the internal region I. The "connection" in the present disclosure means at least an electrical connection, and may or may not mean a physical connection (contact) within a technically consistent range.

The first electrode body has an electrode tab P and an electrode tab Q having a polarity opposite to that of the electrode tab P. For example, in FIG. 3, the electrode tab P is a negative electrode tab and the electrode tab Q is a positive electrode tab. On the other hand, the second electrode body has an electrode tab R having a polarity opposite to that of the electrode tab P, and an electrode tab S having a polarity opposite to that of the electrode tab R. For example, in FIG. 3, the electrode tab R is a positive electrode tab and the electrode tab S is a negative electrode tab. Although not shown, when the electrode tab P is a positive electrode tab, the electrode tab Q is a negative electrode tab, the electrode tab R is a negative electrode tab, and the electrode tab S is a positive electrode tab.

Further, as shown in FIGS. 3 and 1B, one end of the positive electrode terminal 110 is connected to the positive electrode tab 15t (electrode tab Q) in the internal region I, and the other end of the positive electrode terminal 110 is the external region O. Is located in. Similarly, one end of the negative electrode terminal 120 is connected to the negative electrode tab 21t (electrode tab S) in the internal region I, and the other end of the negative electrode terminal 120 is arranged in the external region O. Further, as shown in FIG. 3, the first electrode body 10 and the second electrode body 20 may be laminated along the thickness direction _DT via the insulating member 30. Examples of the material of the insulating member include a resin, and specific examples of the resin include a polyolefin resin such as polypropylene (PP) and polyethylene (PE), a polyimide resin, and a polyphenylene sulfide resin (PPS).

2. 2. The electrode body FIG. 8A is a schematic plan view illustrating the electrode body in the present disclosure, and FIG. 8B is a side view of FIG. 8A. The electrode body E shown in FIGS. 8A and 8B is a collection of current of the positive electrode layer 4, the negative electrode layer 2, the separate layer 3 arranged between the positive electrode layer 4 and the negative electrode layer 2, and the positive electrode layer 4. It has a positive electrode current collector 5 that collects electricity from the negative electrode layer 2 and a negative electrode current collector 1 that collects electricity from the negative electrode layer 2. The positive electrode current collector 5 has a positive electrode tab 5t at a position that does not overlap with the positive electrode layer 4 in a plan view. Similarly, the negative electrode current collector 1 has a negative electrode tab 1t at a position that does not overlap with the negative electrode layer 2 in a plan view.

Further, as shown in FIG. 8A, the positive electrode tab 5t and the negative electrode tab 1t may be arranged on different opposite sides (sides s1 and s2) in a plan view (both-sided tab structure). .. On the other hand, although not shown, the positive electrode tab and the negative electrode tab may be arranged on the same side (one-sided tab structure). Further, the plan view shape of the electrode body (planar view shape excluding the positive electrode tab and the negative electrode tab) is, for example, a rectangular shape.

The electrode body in the present disclosure may have one power generation unit having a positive electrode layer, a separate layer, and a negative electrode layer, may have two, or may have three or more. When the electrode body has a plurality of power generation units, they may be connected in parallel or may be connected in series.

FIG. 9 is a schematic cross-sectional view illustrating the electrode body in the present disclosure, and is a schematic cross-sectional view showing a state in which a plurality of power generation units are connected in parallel. The electrode body E shown in FIG. 9 includes a first negative electrode layer 2a, a first separate layer 3a, a first positive electrode layer 4a, and a first negative electrode layer 2a, a first separate layer 3a, and a first positive electrode layer 4a arranged in order from the negative electrode current collector 1 and one surface s11 of the negative electrode current collector 1. The second negative electrode layer 2b, the second separate layer 3b, the second positive electrode layer 4b, and the second positive electrode current collector 5b arranged in order from the first positive electrode current collector 5a and the other surface s12 of the negative electrode current collector 1. And have. The first positive electrode current collector 5a and the second positive electrode current collector 5b are connected to form a positive electrode tab 5t. Further, an insulating protective layer 7 is provided between the second positive electrode current collector 5b and the side surface portion of the negative electrode (negative electrode current collector 1, first negative electrode layer 2a, second negative electrode layer 2b) in order to suppress a short circuit. Is placed.

The electrode body E shown in FIG. 9 is useful as an electrode body used in an all-solid-state battery including, for example, a solid electrolyte layer containing an inorganic solid electrolyte such as an oxide solid electrolyte and a sulfide solid electrolyte. In an all-solid-state battery containing an inorganic solid electrolyte, it is necessary to press the electrode body at a very high pressure in order to form a good ion conduction path. At this time, since the electrode body E shown in FIG. 9 has a symmetrical structure of the other layers with respect to the negative electrode current collector 1, stress is generated due to the difference in elasticity between the positive electrode layer and the negative electrode layer. It has the advantage of being difficult. Specifically, the electrode body E shown in FIG. 9 has a first negative electrode layer 2a, a first separate layer 3a, a first positive electrode layer 4a, and a first on one surface s11 with reference to the negative electrode current collector 1. The positive electrode current collector 5a is arranged in this order, and the second negative electrode layer 2b, the second separate layer 3b, the second positive electrode layer 4b, and the second positive electrode current collector 5b are arranged in this order on the other surface s12. ing. As described above, since the configurations of the other layers are symmetrical with respect to the negative electrode current collector 1, stress is unlikely to occur due to the difference in elasticity between the positive electrode layer and the negative electrode layer. As a result, it is possible to suppress the occurrence of breakage of the negative electrode current collector and the occurrence of cracking in the positive electrode layer and the negative electrode layer. Further, in the present disclosure, a plurality of electrode bodies E shown in FIG. 9 may be used and they may be laminated in the thickness direction. At that time, the facing positive electrode current collectors (the first positive electrode current collector 5a in one electrode body E and the second positive electrode current collector 5b in the other electrode body E) may be separate members from each other. , The same member may be used (one positive electrode current collector may be shared).

Further, the electrode body E shown in FIG. 9 has two positive electrode current collectors for one negative electrode current collector. On the other hand, the electrode body in the present disclosure may have two negative electrode current collectors for one positive electrode current collector. That is, the electrode body in the present disclosure is a first positive electrode layer, a first separate layer, a first negative electrode layer, and a first negative electrode current collector arranged in order from one surface of the positive electrode current collector and the positive electrode current collector. It may have a body and a second positive electrode layer, a second separate layer, a second negative electrode layer, and a second negative electrode current collector arranged in order from the other surface of the positive electrode collector. In this case, the first negative electrode current collector and the second negative electrode current collector may be connected to form a negative electrode tab.

The positive electrode layer contains at least a positive electrode active material. Further, the positive electrode layer may contain at least one of a conductive material, an electrolyte and a binder. Examples of the positive electrode active material include an oxide active material. Examples of the oxide active material include a rock salt layered active material such as LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , a spinel type active material such as LiMn ₂ O ₄ , and an olivine type active material such as LiFePO ₄ . Can be mentioned. Further, sulfur (S) may be used as the positive electrode active material. The shape of the positive electrode active material is, for example, particles. Examples of the conductive material include a carbon material. The electrolyte may be a liquid electrolyte or a solid electrolyte. The liquid electrolyte (electrolyte solution) contains, for example, a supporting salt such as LiPF ₆ and a solvent such as a carbonate-based solvent. The solid electrolyte may be an organic solid electrolyte such as a gel electrolyte, or may be an inorganic solid electrolyte such as an oxide solid electrolyte or a sulfide solid electrolyte. Examples of the binder include rubber-based binders and fluoride-based binders.

The negative electrode layer contains at least the negative electrode active material. Further, the negative electrode layer may contain at least one of a conductive material, an electrolyte and a binder. Examples of the negative electrode active material include metal active materials such as Li and Si, carbon active materials such as graphite, and oxide active materials such as Li ₄ Ti ₅ O ₁₂ . The shape of the negative electrode active material is, for example, a particle shape or a foil shape. The conductive material, electrolyte and binder are the same as those described above. The separate layer contains at least an electrolyte. The electrolyte may be a liquid electrolyte or a solid electrolyte. Examples of the material of the positive electrode current collector include aluminum, SUS, nickel, and carbon. Examples of the material of the negative electrode current collector include copper, SUS, nickel, and carbon. The shapes of the positive electrode current collector and the negative electrode current collector are, for example, foil-shaped.

3. 3. Laminated exterior body The laminated exterior body in the present disclosure has an internal region for accommodating the electrode body, and a sealing region located outside the internal region for sealing the electrode body. The laminated exterior body has, for example, a heat-resistant resin layer which is an outer layer, a metal foil layer which is an intermediate layer, and a heat-sealing resin layer which is an inner layer. A seal region is formed by heat-sealing the heat-sealed resin layers to each other. In the present disclosure, the electrode body is sandwiched by bending one laminated sheet, and then, in a plan view, a sealing region is formed around the electrode body (three sides excluding the bent portion) to form a laminated exterior body. May be formed. Further, the laminated exterior body may have an embossed portion for forming an internal region.

As described above, the laminated exterior body in the present disclosure sandwiches the electrode body by bending one laminated sheet, and then, in a plan view, a sealing area is formed around the electrode body (three sides excluding the bent portion). Obtained by forming. On the other hand, a laminated exterior body is known in which an electrode body is sandwiched between two laminated sheets, and then, in a plan view, a seal region is formed around the electrode body (four sides). The laminated exterior body in the present disclosure has an advantage that the number of heat sealing steps can be reduced because it is not necessary to form a sealing region at the bent portion. Further, since it is not necessary to form a seal region in the bent portion, there is an advantage that heat damage is less likely to be given to the electrode body.

In the laminated exterior body (laminate sheet), the heat-resistant resin layer functions as a base material layer, the metal foil layer functions as a barrier layer, and the heat-sealed resin layer functions as a sealant layer. Examples of the resin used for the heat-resistant resin layer include polyamides such as nylon, polyethylene terephthalate, methyl polymethacrylate, polypropylene, polycarbonate, and polyalkylene terephthalate. Examples of the metal material used for the metal foil layer include aluminum, stainless steel, titanium, nickel, and copper. Examples of the resin used for the heat-weldable resin layer include acid-modified polyolefin, polyethylene, and polypropylene. The thickness of each layer constituting the laminated sheet is not particularly limited, but is, for example, 1 μm or more and 1000 μm or less.

4. Battery The type of battery in the present disclosure is not particularly limited, but is typically a lithium ion secondary battery. Further, the use of the battery in the present disclosure is not particularly limited, and examples thereof include a power source for a vehicle such as a hybrid vehicle, an electric vehicle, a gasoline vehicle, and a diesel vehicle. In particular, it is preferably used as a power source for driving a hybrid vehicle or an electric vehicle. Further, the battery in the present disclosure may be used as a power source for a moving body other than a vehicle (for example, a railway, a ship, an aircraft), or may be used as a power source for an electric product such as an information processing device.

The present disclosure is not limited to the above embodiment. The above embodiment is an example, and any object having substantially the same structure as the technical idea described in the claims of the present disclosure and having the same effect and effect is the present invention. Included in the technical scope of the disclosure.

10 ... 1st electrode body 20 ... 2nd electrode body 30 ... Insulation member 40 ... Connection member 50 ... Laminate exterior body 51 ... 1st side 52 ... 2nd side 71 ... Resin layer A
72 ... Resin layer B
100 ... Battery 110 ... Positive terminal 120 ... Negative terminal

Claims (1)

A battery comprising an electrode body and a laminated exterior body.
The laminated exterior body has a first side and a second side facing the first side in a plan view.
The first side is the end of the bent portion where the laminated sheet is bent.
The second side is an end portion of a sealing region for sealing the electrode body.
The electrode body has a first resin structure having a resin layer A on the side surface on the first side side and a resin layer B arranged outside the resin layer A and having a Young's modulus smaller than that of the resin layer A. Equipped with a part
The electrode body is provided with a second resin structure portion having a resin layer C on the side surface on the second side side.
In a plan view, the width of the electrode body including the first resin structure portion and the second resin structure portion is W, the width of the first resin structure portion is W ₁ , and the width of the second resin structure portion is defined as W 1. When W ₂ , the W ₁ and the W ₂ are 0.03 W or less, respectively.
In the first resin structure portion, the thickness of the resin layer A is 20% or more and 60% or less with respect to the total thickness of the resin layer A and the resin layer B.

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