JP2020145149A - Power storage device - Google Patents

Abstract

To provide a power storage device capable of achieving an improvement in safety.SOLUTION: A power storage device 10 includes four or more power storage elements 100 and three or more intermediate layers (spacers 200) respectively disposed between adjacent two power storage elements 100 among the four or more power storage elements 100. The three or more intermediate layers include a first intermediate layer (spacer 203), and a second intermediate layer (spacer 202) and a third intermediate layer (spacer 204) which have higher heat insulation than the first intermediate layer, the first intermediate layer being disposed between the second intermediate layer and the third intermediate layer.SELECTED DRAWING: Figure 3

Description

The present invention relates to a power storage device including a plurality of power storage elements and an intermediate layer arranged between the plurality of power storage elements.

Conventionally, a power storage device including a plurality of power storage elements and an intermediate layer arranged between the plurality of power storage elements is known. For example, Patent Document 1 discloses a power supply device (power storage device) having a configuration in which a separator (intermediate layer) is arranged between a plurality of secondary battery cells (power storage elements).

JP-A-2015-111493

However, in the above-mentioned conventional power storage device, when the power storage element generates heat, a thermal chain of the power storage element may occur. That is, in the above-mentioned conventional power storage device, an intermediate layer is arranged between a plurality of power storage elements, but the inventor of the present application has found that when the power storage element generates heat, the heat from the power storage element exceeds the intermediate layer. It was found that there is a risk that it will be sequentially transmitted (heat chained) to the adjacent power storage element. As described above, the inventor of the present application has found that there is a point to be further improved in safety even in the above-mentioned conventional configuration.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a power storage device capable of improving safety.

In order to achieve the above object, the power storage device according to one aspect of the present invention is arranged between four or more power storage elements and two adjacent two power storage elements among the four or more power storage elements. The above-mentioned intermediate layers are provided, and the three or more intermediate layers include a first intermediate layer and a second intermediate layer and a third intermediate layer having higher heat insulating properties than the first intermediate layer. The first intermediate layer is arranged between the second intermediate layer and the third intermediate layer.

According to this, in the power storage device, the three or more intermediate layers each arranged between two adjacent power storage elements are the first intermediate layer and the second intermediate layer having higher heat insulating property than the first intermediate layer. And a third intermediate layer, and the first intermediate layer is arranged between the second intermediate layer and the third intermediate layer. By arranging the first intermediate layer between the second intermediate layer and the third intermediate layer having higher heat insulating properties than the first intermediate layer in this way, a plurality of electricity storages sandwiching the first intermediate layer having low heat insulating properties are interposed. A second intermediate layer and a third intermediate layer having high heat insulating properties are arranged on both sides of the element. Therefore, even if the power storage element sandwiching the first intermediate layer having low heat insulating property generates heat and the first intermediate layer cannot prevent the heat chain from the power storage element, the second intermediate layer having high heat insulating property is arranged on both sides thereof. The intermediate layer and the third intermediate layer can suppress the generation of heat chains from the power storage element. As a result, the safety of the power storage device can be improved.

Further, the second intermediate layer and the third intermediate layer may be thicker than the first intermediate layer.

According to this, in the power storage device, the second intermediate layer and the third intermediate layer having high heat insulating properties are thicker than the first intermediate layers having low heat insulating properties. By forming the second intermediate layer and the third intermediate layer thicker than the first intermediate layer in this way, the second intermediate layer and the third intermediate layer having higher heat insulating properties than the first intermediate layer can be easily formed. Can be formed. In addition, since it is possible to suppress the generation of heat chains of the power storage element without making all the intermediate layers thick, the safety of the power storage device can be improved while saving the space of the power storage device. It can be improved.

Further, the three or more intermediate layers further have a fourth intermediate layer having a lower heat insulating property than the third intermediate layer, and the third intermediate layer is the first intermediate layer and the fourth intermediate layer. It may be arranged in between.

According to this, the power storage device further has a fourth intermediate layer having a lower heat insulating property than the third intermediate layer, and the third intermediate layer is arranged between the first intermediate layer and the fourth intermediate layer. Has been done. That is, the intermediate layers having high heat insulating properties (second intermediate layer and third intermediate layer) and the intermediate layers having low heat insulating properties (first intermediate layer and fourth intermediate layer) are alternately arranged. As a result, even if the intermediate layer having low heat insulating properties cannot prevent the heat chain from the power storage element, the intermediate layer having high heat insulating properties can quickly suppress the generation of heat chains from the power storage element. Therefore, the safety of the power storage device can be improved.

Further, the fourth intermediate layer may be arranged at the end of the three or more intermediate layers.

According to this, in the power storage device, the fourth intermediate layer having low heat insulating property is arranged at the end of the plurality of intermediate layers. Here, if an intermediate layer having high heat insulating properties is arranged at the end of the plurality of intermediate layers, the intermediate layer can suppress only the heat chain from the power storage element on the end side of the intermediate layer. Therefore, a fourth intermediate layer having low heat insulating properties is arranged at the end of the plurality of intermediate layers. As a result, since a plurality of power storage elements sandwiching the fourth intermediate layer are arranged on the end side of the intermediate layer having high heat insulating properties, it is possible to suppress the generation of heat chains from the plurality of power storage elements. it can. By arranging the intermediate layers having low heat insulating properties at the ends of the plurality of intermediate layers in this way, it is possible to efficiently suppress the generation of heat chains from the power storage element and improve the safety of the power storage device. Can be planned.

The present invention can be realized not only as such a power storage device, but also as a plurality of intermediate layers included in the power storage device.

According to the power storage device of the present invention, safety can be improved.

It is a perspective view which shows the appearance of the power storage device which concerns on embodiment. It is an exploded perspective view which shows the structure of the power storage element which concerns on embodiment. It is a side view which shows the structure of the spacer provided in the power storage device which concerns on embodiment. It is a side view which shows the structure of the spacer provided in the power storage device which concerns on modification 1 of embodiment. It is a side view which shows the structure of the spacer provided in the power storage device which concerns on the modification 2 of embodiment. It is a side view which shows the structure of the gas layer provided in the power storage device which concerns on modification 3 of embodiment.

Hereinafter, the power storage device according to the embodiment (and its modification) of the present invention will be described with reference to the drawings. The embodiments described below are comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. Further, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept are described as arbitrary components. Further, each figure is a schematic view, and the dimensions and the like are not necessarily exactly shown. Further, in each figure, the same or similar components are designated by the same reference numerals.

Further, in the following description and drawings, the direction in which the pair of (positive electrode side and negative electrode side) electrode terminals in one power storage element is arranged or the direction in which the short side surfaces of the container of the power storage element face each other is defined as the X-axis direction. .. The direction in which the plurality of power storage elements and the plurality of intermediate layers (spacers, etc.) are arranged, the direction opposite to the long side surface of the container of the power storage element, or the thickness direction of the container is defined as the Y-axis direction. The alignment direction between the container body and the lid of the power storage element, the alignment direction between the exterior body body and the lid of the power storage device, or the vertical direction is defined as the Z-axis direction. These X-axis directions, Y-axis directions, and Z-axis directions intersect each other (orthogonally in the present embodiment). Depending on the usage mode, the Z-axis direction may not be the vertical direction, but for convenience of explanation, the Z-axis direction will be described below as the vertical direction. Further, in the following description, for example, the X-axis plus direction indicates the arrow direction of the X-axis, and the X-axis minus direction indicates the direction opposite to the X-axis plus direction. The same applies to the Y-axis direction and the Z-axis direction.

(Embodiment)
[1 General description of power storage device 10]
First, a general description of the power storage device 10 according to the present embodiment will be given. FIG. 1 is a perspective view showing the appearance of the power storage device 10 according to the present embodiment. It should be noted that the figure is a view showing the inside of the exterior body 300 by seeing through the exterior body 300, and the exterior body 300 is shown by a broken line.

The power storage device 10 is a device capable of charging electricity from the outside and discharging electricity to the outside. For example, the power storage device 10 is a battery module (assembled battery) used for power storage and power supply. Specifically, the power storage device 10 includes, for example, automobiles such as electric vehicles (EV), hybrid electric vehicles (HEV) or plug-in hybrid electric vehicles (PHEV), motorcycles, watercraft, snowmobiles, agricultural machinery, and construction. Used as a stationary battery for driving or starting an engine of a machine or a moving body such as a railroad vehicle for an electric railway such as a train, a monorail or a linear motor car, or for a household or a generator. Be done.

As shown in FIG. 1, the power storage device 10 includes a plurality of (six in the present embodiment) power storage elements 100, a plurality of (five in the present embodiment) spacers 200, and an exterior body 300. There is. The power storage device 10 includes a bus bar that electrically connects the power storage elements 100 to each other, a bus bar frame (bus bar plate) that positions the bus bar, a circuit board and a relay for monitoring the charge state and the discharge state of the power storage element 100, and the like. The electric device, side spacers, end spacers, and the like for restraining a plurality of power storage elements 100 may also be provided, but these are not shown and detailed description will be omitted.

The power storage element 100 is a secondary battery (cell battery) capable of charging electricity and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. .. The power storage element 100 has a flat rectangular parallelepiped shape (square shape), and is arranged adjacent to the spacer 200. That is, each of the plurality of power storage elements 100 is alternately arranged with each of the plurality of spacers 200, and is arranged in the Y-axis direction. In the present embodiment, six power storage elements 100 (power storage elements 101 to 106) are arranged at positions sandwiching each of the five spacers 200. A detailed description of the configuration of the power storage element 100 will be described later.

The number of power storage elements 100 is not limited to six, and may be four or more. Further, the connection form of the power storage element 100 is not particularly limited, and all of them may be connected in series, or any of the power storage elements 100 may be connected in parallel. Further, the shape of the power storage element 100 is not limited to the rectangular parallelepiped shape, and may be a polygonal pillar shape, a cylindrical shape, an elliptical pillar shape, a long cylindrical shape, or the like other than the rectangular parallelepiped shape, and the power storage element is a laminated type. You can also do it. Further, the power storage element 100 is not limited to the non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery, or may be a capacitor. Further, the power storage element 100 may not be a secondary battery but a primary battery that can use the stored electricity without being charged by the user. Further, the power storage element 100 may be a battery using a solid electrolyte.

The spacer 200 is a rectangular and plate-shaped spacer arranged on the side (Y-axis plus direction or Y-axis minus direction) of the power storage element 100. Specifically, the spacer 200 is a spacer that is arranged between two adjacent power storage elements 100 and electrically insulates between the two power storage elements 100. In the present embodiment, five (five) spacers 200 (spacers 201 to 205) are arranged corresponding to the six power storage elements 100. When the number of power storage elements 100 is other than 6, the number of spacers 200 is also appropriately changed according to the number of power storage elements 100, but as described above, the number of power storage elements 100 is 4 or more. Therefore, the number of spacers 200 is three or more.

The spacer 200 includes, for example, polycarbonate (PC), polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate. (PBT), polyether ether ketone (PEEK), tetrafluoroethylene / perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyether sulfone (PES), ABS resin, or a composite material thereof, etc. It is formed of the insulating member of. The spacer 200 may be made of a material other than resin such as rubber (natural rubber, synthetic rubber). However, the spacer 200 is preferably formed of a member having heat insulating properties (including a member having low heat insulating properties). A detailed description of the configuration of the spacers 200 (spacers 201-205) will be described later.

The exterior body 300 is a container (module case) having a substantially rectangular parallelepiped shape (box shape) that constitutes the exterior body of the power storage device 10. That is, the exterior body 300 is arranged outside the power storage element 100 and the like, accommodates these power storage elements 100 and the like, and protects them from impacts and the like. Further, the exterior body 300 is composed of an insulating member similar to the spacer 200, such as PC, PP, PE, etc. As a result, the exterior body 300 prevents the power storage element 100 and the like from coming into contact with an external metal member or the like. The exterior body 300 has a box-shaped main body portion and a lid portion, and the lid portion is provided with two external terminals (external connection terminals on the positive electrode side and the negative electrode side). The illustration is omitted, and the detailed description is also omitted.

[2 Explanation of configuration of power storage element 100]
Next, the configuration of the power storage element 100 will be described in detail. Since all the power storage elements 100 (storage elements 101 to 106) included in the power storage device 10 have the same configuration, the configuration of one power storage element 100 will be described in detail below. FIG. 2 is a perspective view showing the configuration of the power storage element 100 according to the present embodiment. Specifically, FIG. 2 is an exploded perspective view showing each component included in the power storage element 100 in an exploded manner.

As shown in FIG. 2, the power storage element 100 includes a container 110 and a pair of electrode terminals 120 (positive electrode terminal and negative electrode terminal), and a pair of current collectors 130 (positive electrode current collectors 130) are inside the container 110. Body and negative electrode current collector) and electrode body 140 and the like are housed. In order to improve the insulation and airtightness between the container 110 (the lid 112 described later) and the electrode terminal 120, and between the container 110 (the lid 112 described later) and the current collector 130. A gasket or the like is arranged, and an electrolytic solution (non-aqueous electrolyte) is also contained inside the container 110, but these are not shown. The type of the electrolytic solution is not particularly limited as long as it does not impair the performance of the power storage element 100, and various types can be selected. Further, in addition to the above configuration, spacers may be arranged on the side of the current collector 130 or the like, or an insulating sheet covering the surface of the container 110 may be arranged.

The container 110 is a rectangular parallelepiped (square) container having a container body 111 having an opening and a lid 112 that closes the opening of the container body 111. The container body 111 is a rectangular tubular member having a bottom that constitutes the main body of the container 110, has two long side surface portions 111a on both side surfaces in the Y-axis direction, and two on both side surfaces in the X-axis direction. It has a short side surface portion 111b and a bottom surface portion 111c on the negative direction side of the Z axis.

Specifically, the long side surface portion 111a is a rectangular and flat surface portion that forms the long side surface of the container 110. In other words, the long side surface portion 111a is a surface portion adjacent to the bottom surface portion 111c and the short side surface portion 111b and having a larger area than the short side surface portion 111b. In the present embodiment, the long side surface portion 111a is a surface portion having a larger area (largest area) than the bottom surface portion 111c and the short side surface portion 111b. The short side surface portion 111b is a rectangular and flat surface portion forming the short side surface of the container 110. In other words, the short side surface portion 111b is a surface portion adjacent to the bottom surface portion 111c and the long side surface portion 111a and having a smaller area than the long side surface portion 111a. In the present embodiment, the short side surface portion 111b is a surface portion having a smaller area (smallest area) than the bottom surface portion 111c and the long side surface portion 111a. The bottom surface portion 111c is a rectangular and flat surface portion that forms the bottom surface of the container 110.

The lid 112 is a rectangular plate-shaped member that constitutes the lid of the container 110, and is arranged on the Z-axis plus direction side of the container body 111. Further, the lid 112 also includes a gas discharge valve 113 that releases the pressure inside the container 110 when the pressure rises, a liquid injection unit 114 for injecting the electrolytic solution into the inside of the container 110, and the like. It is provided.

With such a configuration, the container 110 has a structure in which the electrode body 140 and the like are housed inside the container body 111, and then the container body 111 and the lid 112 are joined by welding or the like to seal the inside. It has become. The material of the container 110 (container body 111 and lid 112) is not particularly limited, but is preferably a weldable (bondable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate.

The electrode terminal 120 is a terminal (positive electrode terminal and negative electrode terminal) that is electrically connected to the positive electrode plate and the negative electrode plate of the electrode body 140 via the current collector 130. That is, the electrode terminal 120 leads the electricity stored in the electrode body 140 to the external space of the power storage element 100, and also introduces electricity into the internal space of the power storage element 100 in order to store electricity in the electrode body 140. It is a metal member of. The electrode terminal 120 is made of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

The electrode body 140 includes a positive electrode plate, a negative electrode plate, and a separator, and is a power storage element (power generation element) capable of storing electricity. The positive electrode plate is an electrode plate in which a positive electrode active material layer is formed on a positive electrode base material layer which is a long strip-shaped current collecting foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is an electrode plate in which a negative electrode active material layer is formed on a negative electrode base material layer which is a long strip-shaped current collecting foil made of a metal such as copper or a copper alloy. As the active material used for the positive electrode active material layer and the negative electrode active material layer, known materials can be appropriately used as long as they can occlude and release lithium ions. The separator is a microporous sheet made of resin or the like.

The electrode body 140 is formed by arranging (stacking) a separator between the positive electrode plate and the negative electrode plate and winding the electrode body 140. In the present embodiment, the cross-sectional shape of the electrode body 140 is shown as an oval shape, but an elliptical shape, a circular shape, a polygonal shape, or the like may be used. Further, the electrode body 140 may have a shape wound around the X-axis direction as a winding axis as shown in FIG. 2, or may have a shape wound around the Z-axis direction as a winding axis. Instead of the winding type, it may have a laminated type in which flat plate-shaped electrode plates are laminated, or a bellows type in which the electrode plates are folded in a bellows shape.

The current collector 130 is a member (positive electrode current collector and negative electrode current collector) having conductivity and rigidity electrically connected to the electrode terminal 120 and the electrode body 140. The positive electrode current collector is formed of aluminum or an aluminum alloy like the positive electrode base material layer of the positive electrode plate of the electrode body 140, and the negative electrode current collector is the same as the negative electrode base material layer of the negative electrode plate of the electrode body 140. , Formed of copper or copper alloy, etc.

[Explanation of configuration of 3 spacer 200]
Next, the configuration of the spacer 200 (spacers 201 to 205) will be described in detail. FIG. 3 is a side view showing the configuration of spacers 200 (spacers 201 to 205) included in the power storage device 10 according to the present embodiment. Specifically, FIG. 3 shows a state in which the power storage elements 100 (storage elements 101 to 106) and spacers 200 (spacers 201 to 205) shown in FIG. 1 are alternately arranged from the X-axis plus direction side. It is a side view which shows the structure in the case of.

As described above, the spacer 200 is a rectangular and flat spacer parallel to the XZ plane, each of which is arranged adjacent to the two power storage elements 100 between two adjacent power storage elements 100. In the present embodiment, the spacer 200 extends from one end to the other end of the long side surface portion 111a in the X-axis direction and the Z-axis direction so as to cover the entire surface of the long side surface portion 111a of the adjacent power storage element 100. It is installed and arranged. The spacer 200 may be configured to cover only a part of the long side surface portion 111a instead of the entire surface, but it is arranged so as to cover at least the central portion of the long side surface portion 111a in the X-axis direction and the Z-axis direction. preferable. The central portion of the long side surface portion 111a in the Z-axis direction is, for example, the middle three regions when the long side surface portion 111a is divided into five equal parts in the Z-axis direction, and the middle two when divided into four equal parts. It is the area for one or the area for one in the middle when divided into three equal parts. The same applies to the X-axis direction.

Specifically, as shown in FIG. 3, the power storage device 10 has spacers 201 to 205, which are five spacers 200. Here, the plurality of spacers 200 included in the power storage device 10 are an example of three or more intermediate layers. The spacer 202 is an example of the second intermediate layer, the spacer 203 is an example of the first intermediate layer, the spacer 204 is an example of the third intermediate layer, and the spacer 205 is an example of the fourth intermediate layer. This is an example.

These five spacers 200 are arranged side by side in the order of spacers 201, 202, 203, 204 and 205 from the Y-axis minus direction side. That is, the spacer 201 is arranged at the end of the plurality of spacers 200 (three or more intermediate layers) on the negative direction side of the Y axis. The spacer 202 (second intermediate layer) is arranged between the spacer 201 and the spacer 203 (first intermediate layer). The spacer 203 (first intermediate layer) is arranged between the spacer 202 (second intermediate layer) and the spacer 204 (third intermediate layer). The spacer 204 (third intermediate layer) is arranged between the spacer 203 (first intermediate layer) and the spacer 205 (fourth intermediate layer). The spacer 205 (fourth intermediate layer) is arranged at the end of the plurality of spacers 200 (three or more intermediate layers) on the Y-axis positive direction side.

Specifically, the spacer 201 is arranged so as to be sandwiched between the power storage elements 101 and 102. Similarly, the spacer 202 is arranged so as to be sandwiched between the power storage elements 102 and 103. The spacer 203 is arranged so as to be sandwiched between the power storage elements 103 and 104. The spacer 204 is arranged so as to be sandwiched between the power storage elements 104 and 105. The spacer 205 is arranged so as to be sandwiched between the power storage elements 105 and 106.

Further, in these five spacers 200, the thick spacer 200 and the thin spacer 200 are arranged alternately side by side. That is, the spacer 202 (second intermediate layer) is formed to be thicker than the spacer 201 and the spacer 203 (first intermediate layer), and the spacer 204 (third intermediate layer) is formed of the spacer 203 (first intermediate layer) and the spacer 203 (first intermediate layer). It is formed thicker than the spacer 205 (fourth intermediate layer). In the present embodiment, the spacers 201, 203 and 205 are formed to have the same thickness, and the spacers 202 and 204 are formed to have the same thickness and to be thicker than the spacers 201, 203 and 205.

Further, in the present embodiment, the spacers 201 to 205 are made of the same material, and the thicker the spacer, the higher the heat insulating property. Therefore, the spacer 202 (second intermediate layer) has higher heat insulating properties than the spacer 201 and the spacer 203 (first intermediate layer), and the spacer 204 (third intermediate layer) has the spacer 203 (first intermediate layer). And the heat insulating property is higher than that of the spacer 205 (fourth intermediate layer). Specifically, the spacers 201, 203 and 205 have the same heat insulating properties, and the spacers 202 and 204 have the same heat insulating properties and have higher heat insulating properties than the spacers 201, 203 and 205.

Here, the thickness of the spacer 200 means the thickness of the spacer 200 in the Y-axis direction. When the thickness of the spacer 200 in the Y-axis direction is different in the X-axis direction or the Z-axis direction, the maximum thickness in the Y-axis direction is defined as the thickness of the spacer 200. Further, the high heat insulating property of the spacer 200 means that the spacer 200 does not easily transfer heat, for example, the amount of heat transferred from one of the two power storage elements 100 sandwiching the spacer 200 to the other is small. The comparison of these thicknesses and heat insulating properties can be appropriately measured and determined by a known method.

The spacer 201 may be formed thinner than the spacer 202, and may have a thickness different from that of the spacers 203 and 205. The spacer 203 may be formed thinner than the spacers 202 and 204, and may have a thickness different from that of the spacers 201 and 205. The spacer 205 may be formed thinner than the spacer 204 and may have a thickness different from that of the spacers 201 and 203. Further, the spacer 202 may be formed thicker than the spacers 201 and 203, and may have a thickness different from that of the spacer 204. The spacer 204 may be formed thicker than the spacers 203 and 205, and may have a thickness different from that of the spacer 202.

That is, the spacer 201 may have a heat insulating property lower than that of the spacer 202, and may have a heat insulating property different from that of the spacers 203 and 205. The spacer 203 may have a lower heat insulating property than the spacers 202 and 204, and may have a different heat insulating property from the spacers 201 and 205. The spacer 205 may have a heat insulating property lower than that of the spacer 204, and may have a heat insulating property different from that of the spacers 201 and 203. Further, the spacer 202 may have a higher heat insulating property than the spacers 201 and 203, and may have a heat insulating property different from that of the spacer 204. The spacer 204 may have a higher heat insulating property than the spacers 203 and 205, and may have a heat insulating property different from that of the spacer 202. Further, the spacers 201 to 205 may be made of different materials.

[4 Explanation of effect]
As described above, according to the power storage device 10 according to the embodiment of the present invention, as the plurality of spacers 200 (intermediate layers), the spacer 203 (first intermediate layer) and the spacer 202 having higher heat insulating properties than the spacer 203 It has (second intermediate layer) and spacer 204 (third intermediate layer). The spacer 203 is arranged between the spacer 202 and the spacer 204. By arranging the spacer 203 between the spacers 202 and 204 in this way, the spacer 202 having high heat insulating property and the spacer 202 having high heat insulating property are placed on both sides of the plurality of power storage elements 100 (storage elements 103 and 104) sandwiching the spacer 203 having low heat insulating property. 204 will be placed. Therefore, even if the power storage element 103 or 104 generates heat and the spacer 203 cannot prevent the heat chain from the power storage element 103 or 104, the power storage element 103 is provided by the spacers 202 and 204 having high heat insulating properties arranged on both sides thereof. Alternatively, it is possible to suppress the generation of a heat chain from 104. As a result, the safety of the power storage device 10 can be improved.

Further, by arranging the spacer 203 having a low heat insulating property and the spacers 202 and 204 having a high heat insulating property, it is possible to select a position where the heat chain of the power storage element 100 is to be suppressed. Further, since it is possible to suppress the generation of heat chains of the power storage element 100 without making all the spacers 200 spacers having high heat insulating properties, it is possible to reduce costs and the like.

Further, in the power storage device 10, the spacers 202 and 204 having high heat insulating properties are thicker than the spacers 203 having low heat insulating properties. By forming the spacers 202 and 204 thicker than the spacer 203 in this way, the spacers 202 and 204 having higher heat insulating properties than the spacer 203 can be easily formed. Further, since it is possible to suppress the generation of heat chains of the power storage element 100 without making all the spacers 200 thick spacers, the safety of the power storage device 10 can be saved while saving the space of the power storage device 10. It is possible to improve the sex.

Further, the power storage device 10 further has a spacer 205 (fourth intermediate layer) having a lower heat insulating property than the spacer 204, and the spacer 204 is arranged between the spacers 203 and 205. That is, the spacers 200 having high heat insulating properties (spacers 202 and 204) and the spacers 200 having low heat insulating properties (spacers 203 and 205) are alternately arranged. As a result, even if the spacer 200 having a low heat insulating property cannot prevent the heat chain from the power storage element 100, the spacer 200 having a high heat insulating property can quickly suppress the heat chain from the power storage element 100. Therefore, it is possible to improve the safety of the power storage device 10. The same applies to the spacer 201.

Further, in the power storage device 10, the spacer 205 having low heat insulating property is arranged at the end of the plurality of spacers 200. Here, if the spacers 200 having high heat insulating properties are arranged at the ends of the plurality of spacers 200, the spacers 200 can suppress only the heat chain from the power storage element 100 on the end side of the spacers 200. For example, in the present embodiment, the spacer 204 can suppress the heat chain from the power storage elements 105 and 106, but when the spacer 204 is arranged at the position of the spacer 205, the spacer 204 has the heat chain from the power storage element 106. Can only be suppressed. Therefore, spacers 205 having low heat insulating properties are arranged at the ends of the plurality of spacers 200. As a result, a plurality of power storage elements 100 (storage elements 105 and 106) sandwiching the spacer 205 are arranged on the end side of the spacer 204 having high heat insulating properties, so that a heat chain is generated from the plurality of power storage elements 100. Can be suppressed. By arranging the spacers 205 having low heat insulating properties at the ends of the plurality of spacers 200 in this way, it is possible to efficiently suppress the generation of heat chains from the power storage element 100, thereby improving the safety of the power storage device 10. It can be improved. The same applies to the spacer 201. As a result, the number of spacers 200 having high heat insulating properties can be reduced, so that space saving and cost reduction can be achieved.

Further, the spacer 202 is arranged between the spacers 201 and 203 having lower heat insulating properties than the spacer 202. That is, a group of power storage elements (power storage elements 101 and 102 and power storage elements 103 and 104) including a plurality of power storage elements 100 are arranged on both sides of the spacer 202. As a result, the spacer 202 can suppress the generation of a heat chain for each of the power storage element groups.

[Explanation of 5 modified examples]
(Modification example 1)
Next, a modification 1 of the above embodiment will be described. FIG. 4 is a side view showing the configuration of spacers 200 (spacers 202 to 206) included in the power storage device 11 according to the first modification of the present embodiment. Specifically, FIG. 4 is a diagram corresponding to FIG.

As shown in FIG. 4, in the power storage device 11 in this modification, the spacer 202 is arranged at the position of the spacer 201 of the power storage device 10 in the above embodiment, and the spacer 201 is arranged at the position of the spacer 202. That is, in the power storage device 11 in this modification, the spacer 201 and the spacer 202 of the power storage device 10 in the above embodiment are replaced with each other. Since other configurations are the same as those in the above embodiment, detailed description thereof will be omitted.

Also in this configuration, the spacer 203 (first intermediate layer) is arranged between the spacer 202 (second intermediate layer) and the spacer 204 (third intermediate layer). The spacer 204 (third intermediate layer) is arranged between the spacer 203 (first intermediate layer) and the spacer 205 (fourth intermediate layer). The spacer 205 (fourth intermediate layer) is arranged at the end of the plurality of spacers 200 (three or more intermediate layers) on the Y-axis positive direction side.

As described above, according to the power storage device 11 according to the present modification, the same effect as that of the above-described embodiment can be obtained. In particular, in this modification, since the three storage elements 102 to 104 are arranged between the spacers 202 and 204 having high heat insulating properties, the spacers 202 and 204 cause a thermal chain from the three storage elements 102 to 104. Can be suppressed from occurring.

In this way, two or more spacers 200 having low heat insulating properties may be arranged between the two spacers 200 having high heat insulating properties (spacers 202 and 204). That is, three or more power storage elements 100 that sandwich the two or more spacers 200 having low heat insulating properties may be arranged between the two spacers 200 having high heat insulating properties. Further, two or more spacers 200 having high heat insulating properties may be arranged between two spacers 200 having low heat insulating properties (for example, spacers 203 and 205). That is, three or more power storage elements 100 that sandwich the two or more spacers 200 having high heat insulating properties may be arranged between the two spacers 200 having low heat insulating properties.

(Modification 2)
Next, a modification 2 of the above embodiment will be described. FIG. 5 is a side view showing the configuration of spacers 210 (spacers 211 to 215) included in the power storage device 12 according to the second modification of the present embodiment. Specifically, FIG. 5 is a diagram corresponding to FIG.

As shown in FIG. 5, in the power storage device 12 in this modification, the spacers 211 to 215, which are the five spacers 210, are located at the positions of the spacers 201 to 205, which are the five spacers 200 of the power storage device 10 in the above embodiment. Have been placed. Here, the plurality of spacers 210 included in the power storage device 12 are an example of three or more intermediate layers. The spacer 212 is an example of the second intermediate layer, the spacer 213 is an example of the first intermediate layer, the spacer 214 is an example of the third intermediate layer, and the spacer 215 is an example of the fourth intermediate layer. This is an example. Since other configurations are the same as those in the above embodiment, detailed description thereof will be omitted.

In this modification, in these five spacers 210, spacers 210 made of a material having high heat insulating properties and spacers 210 made of a material having low heat insulating properties are alternately arranged side by side. That is, the spacer 212 (second intermediate layer) is formed of a material having higher heat insulating properties than the spacer 211 and the spacer 213 (first intermediate layer), and the spacer 214 (third intermediate layer) is the spacer 213 (first intermediate layer). The layer) and the spacer 215 (fourth intermediate layer) are made of a material having higher heat insulating properties. The material having high heat insulating properties means a material that does not easily transfer heat, for example, a material having low thermal conductivity. This comparison of heat insulating properties can be determined by measuring by a known method as appropriate.

Specifically, in this modification, the spacers 211, 213 and 215 are made of the same heat insulating material, the spacers 212 and 214 are made of the same heat insulating material, and are more heat insulating than the spacers 211, 213 and 215. It is made of a highly resistant material. The material of the spacers 211 to 215 is not particularly limited as long as such conditions are satisfied. For example, the spacers 211, 213 and 215 are formed of PE, and the spacers 212 and 214 are formed of PP, PC, or a mica plate formed of a mica material formed by accumulating and bonding mica pieces. Has been done. Alternatively, the spacers 211, 213 and 215 may be formed of a mica plate, the spacers 212 and 214 may be formed of PP or PC, and the spacers 211, 213 and 215 may be formed of a PC of the spacer 212 and 214 may be formed by PP. Further, the spacers 211 to 215 are formed to have the same thickness.

The spacers 211, 213, and 215 may be made of different materials, or may be made of a material that does not have heat insulating properties. Further, the spacers 212 and 214 may be formed of different materials, and if the heat insulating property is higher than the spacers 211, 213 and 215, the spacers 212 and 214 are formed to be thinner than the spacers 211, 213 and 215. You may.

As described above, according to the power storage device 12 according to the present modification, the same effect as that of the above-described embodiment can be obtained. In particular, in this modification, the spacers 212 and 214 can be formed to be thin, so that space can be saved.

(Modification 3)
Next, a modification 3 of the above embodiment will be described. FIG. 6 is a side view showing the configuration of the gas layer 220 (gas layers 221 to 225) included in the power storage device 13 according to the third modification of the present embodiment. Specifically, FIG. 6 is a diagram corresponding to FIG.

As shown in FIG. 6, the power storage device 13 in this modification is located at the positions of the spacers 201 to 205, which are the five spacers 200 of the power storage device 10 in the above embodiment, and the gas layers 221 to which are the five gas layers 220. 225 are arranged. Here, the plurality of gas layers 220 included in the power storage device 13 are examples of three or more intermediate layers. The gas layer 222 is an example of the second intermediate layer, the gas layer 223 is an example of the first intermediate layer, the gas layer 224 is an example of the third intermediate layer, and the gas layer 225 is the first. It is an example of the four intermediate layers. Since other configurations are the same as those in the above embodiment, detailed description thereof will be omitted.

In this modification, in these five gas layers 220, the gas layer 220 having a thick thickness (large width) in the Y-axis direction and the gas layer 220 having a thin thickness (small width) in the Y-axis direction are alternately arranged. They are arranged side by side. That is, the gas layer 222 (second intermediate layer) is formed to be thicker than the gas layer 221 and the gas layer 223 (first intermediate layer), and the gas layer 224 (third intermediate layer) is the gas layer 223 (third intermediate layer). It is formed thicker than the gas layer 225 (fourth intermediate layer) and the gas layer 225 (one intermediate layer).

Specifically, in this modification, the gas layers 221, 223 and 225 have the same thickness, the gas layers 222 and 224 have the same thickness, and the gas layers 221 and 223 and 225 are thicker than the gas layers 221 and 223 and 225. .. For example, the gas layers 221 to 225 are air layers in which air is arranged. A gas other than air may be arranged in the gas layers 221 to 225. Further, a gas having a high heat insulating property may be arranged in the gas layers 222 and 224.

As described above, according to the power storage device 13 according to the present modification, the same effect as that of the above-described embodiment can be obtained. In particular, in this modification, since the gas layers 221 to 225 are arranged instead of the spacers, the manufacturing process can be simplified and the cost can be reduced by reducing the number of parts.

(Other variants)
Although the power storage device according to the present embodiment and its modified example has been described above, the present invention is not limited to the above-described embodiment and its modified example. That is, the embodiments disclosed this time and examples thereof are exemplary in all respects and are not limiting, and the scope of the present invention is indicated by the claims and is equivalent to the claims. Includes all changes in meaning and scope.

For example, in the above-described embodiment and its modification, the power storage device has five intermediate layers, but the power storage device may have three or more intermediate layers. For example, in the above embodiment and the first modification, the power storage devices 10 and 11 may have spacers 202, 203 and 204. In the second modification, the power storage device 12 may have spacers 212, 213 and 214, and in the third modification, the power storage device 13 may have gas layers 222, 223 and 224. Just do it.

Further, in the above-described embodiment and its modifications, spacers and gas layers are exemplified as intermediate layers (first intermediate layer to fourth intermediate layer), but the present invention is not limited thereto. For example, the intermediate layer is an exterior sheet (insulating sheet) arranged on the long side surface portion 111a of the container 110 of the power storage element 100, an adhesive (adhesive layer) applied to the long side surface portion 111a, or the like. You may. That is, for example, in the above embodiment, the exterior sheet may be arranged in place of the spacers 201, 203 and 205, or a plurality of insulating sheets may be arranged in an overlapping manner in place of the spacers 202 and 204. .. Alternatively, for example, in the above embodiment, a thin adhesive layer may be arranged instead of the spacers 201, 203 and 205, or a thick adhesive layer may be arranged instead of the spacers 202 and 204. Good. The same applies to the first and second modifications.

Further, in the above-described embodiment and its modification, the fourth intermediate layer is arranged at the end of the plurality of intermediate layers, but the fourth intermediate layer is not arranged at the end. May be good.

Further, the embodiment constructed by arbitrarily combining the above-described embodiment and the above-described modification is also included in the scope of the present invention. For example, the configuration of the modification 1 may be applied to the configuration of the modification 2, or the configuration of the modification 1 may be applied to the configuration of the modification 3. Further, the configuration of the embodiment or the modification 2 and the configuration of the modification 3 may be combined. That is, both the spacer and the gas layer may be arranged at the position of one intermediate layer. In other words, one intermediate layer may be composed of both a spacer and a gas layer. Further, as described above, since an exterior sheet or an adhesive layer may be arranged as the intermediate layer, one intermediate layer is a combination of two or more of a spacer, a gas layer, an exterior sheet, an adhesive layer and the like. It may be composed of. For example, one intermediate layer may be composed of two spacers and an insulating sheet, two insulating sheets and a gas layer, or three spacers, a gas layer and an insulating sheet. It may be done. The same applies to the adhesive layer and the like.

Further, the present invention can be realized not only as such a power storage device but also as a plurality of intermediate layers included in the power storage device.

The present invention can be applied to a power storage device or the like provided with a power storage element such as a lithium ion secondary battery.

10, 11, 12, 13 Power storage device 100, 101, 102, 103, 104, 105, 106 Power storage element 110 Container 111 Container body 111a Long side surface 111b Short side surface 111c Bottom surface 112 Lid 113 Gas discharge valve 114 Injection Part 120 Electrode terminal 130 Current collector 140 Electrode body 200, 201, 202, 203, 204, 205, 210, 211, 212, 213, 214, 215 Spacer 220, 222, 222, 223, 224, 225 Gas layer 300 Exterior body

Claims (4)

With 4 or more power storage elements
It is provided with three or more intermediate layers, each of which is arranged between two adjacent two power storage elements among the four or more power storage elements.
The three or more intermediate layers include a first intermediate layer and a second intermediate layer and a third intermediate layer having higher heat insulating properties than the first intermediate layer.
The first intermediate layer is a power storage device arranged between the second intermediate layer and the third intermediate layer. The power storage device according to claim 1, wherein the second intermediate layer and the third intermediate layer are thicker than the first intermediate layer. The three or more intermediate layers further have a fourth intermediate layer having a lower heat insulating property than the third intermediate layer.
The power storage device according to claim 1 or 2, wherein the third intermediate layer is arranged between the first intermediate layer and the fourth intermediate layer. The power storage device according to claim 3, wherein the fourth intermediate layer is arranged at an end of the three or more intermediate layers.

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