CN117730452A

CN117730452A - Power storage module

Info

Publication number: CN117730452A
Application number: CN202280053141.2A
Authority: CN
Inventors: 乘峯笙汰; 荻野洋岳; 佐藤香澄
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2021-07-30
Filing date: 2022-07-26
Publication date: 2024-03-19

Abstract

The power storage module (100) has a power storage device (1) and a holder (104) for holding the power storage device (1). The power storage device (1) has a plurality of cylindrical electrode bodies, and a film outer case (4), the film outer case (4) having a plurality of housing portions (12) that respectively wrap the plurality of electrode bodies, and a sealing portion (14) that seals each of the housing portions (12) and connects the plurality of housing portions (12) to each other. The holder (104) is bonded to the sealing portion (14).

Description

Power storage module

Technical Field

The present disclosure relates to an electric storage module.

Background

Conventionally, a power storage module having a plurality of cylindrical power storage devices (e.g., batteries) mounted thereon is known (for example, see patent document 1). In the power storage module disclosed in patent document 1, each power storage device has a cylindrical outer can, and a wound electrode body is accommodated in each outer can.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2014-170613

Disclosure of Invention

Technical problem to be solved by the invention

The power storage module is sometimes used as a power source for a vehicle or a mobile terminal. Therefore, weight reduction of the power storage module is expected. As a method for reducing the weight of the power storage module, it is conceivable to wrap a plurality of electrode assemblies with a common film casing while maintaining the sealing properties of each. Thus, a power storage device having a plurality of electrode bodies is obtained. In this case, the outer can housing each electrode assembly can be eliminated, and therefore the power storage module can be made lightweight.

In such a power storage module including a plurality of electrode assemblies, not only weight reduction but also safety improvement are required. The present inventors have repeatedly studied intensively and thought of a technique for improving the safety of an electric storage module.

The present disclosure has been made in view of such a situation, and an object thereof is to provide a technique for improving the safety of an electric storage module.

Method for solving technical problems

One aspect of the present disclosure is an electric storage module. The power storage module includes a power storage device having a plurality of cylindrical electrode bodies, and a film casing having a plurality of storage units for respectively enclosing the plurality of electrode bodies, and a sealing unit for sealing each storage unit and connecting the plurality of storage units to each other; the holder is adhered to the sealing portion.

Other aspects of the present disclosure are power storage modules. The power storage module includes: an electric storage device; a holder that holds the power storage device; and a filler interposed between the power storage device and the holder, wherein the thermal conductivity at the first temperature is lower than the thermal conductivity at the second temperature lower than the first temperature.

Any combination of the above-described constituent elements, and a scheme of converting the expression of the present disclosure between methods, apparatuses, systems, and the like are also effective as a scheme of the present disclosure.

Effects of the invention

According to the present disclosure, the safety of the power storage module can be improved.

Drawings

Fig. 1 is a perspective view of an electric storage device.

Fig. 2 (a) is a schematic diagram of the power storage device as viewed from the axial direction. Fig. 2 (B) is a schematic diagram of the power storage device as viewed from the second direction.

Fig. 3 (a) to 3 (E) are process drawings of a method for manufacturing the power storage device.

Fig. 4 is a perspective view of the power storage module according to the embodiment.

Fig. 5 is an exploded perspective view of the power storage module.

Fig. 6 is a perspective view of the power storage devices and the holders arranged in the second direction.

Fig. 7 (a) and 7 (B) are cross-sectional views taken along a plane perpendicular to the axial direction of a part of the power storage module.

Fig. 8 (a) is an enlarged view of a part of the filler. Fig. 8 (B) is an enlarged view of the dotted line area in fig. 7 (a).

Fig. 9 (a) is a perspective view of a part of the holder. Fig. 9 (B) is a top view of a part of the cage.

Fig. 10 (a) is a perspective view of the power storage module. Fig. 10 (B) is a cross-sectional view taken along a plane perpendicular to the second direction of a part of the power storage module.

Fig. 11 is a perspective view of a part of the power storage module.

Fig. 12 (a) and 12 (B) are perspective views of a part of the power storage module.

Fig. 13 is a cross-sectional view of a plane perpendicular to a first direction along a part of the power storage module.

Detailed Description

The present disclosure is described below with reference to the drawings based on preferred embodiments. The embodiments are not limited to the present disclosure but are exemplified, and all the features described in the embodiments or combinations thereof do not necessarily represent essential matters of the present disclosure. The same or equivalent components, parts, and processes shown in the drawings are denoted by the same reference numerals, and repetitive description thereof will be omitted as appropriate. The scale and shape of each part shown in each drawing are conveniently set for ease of explanation, and are not limited to those described unless specifically mentioned. In the present specification and claims, unless otherwise specified, terms such as "first," "second," and the like are used to distinguish one component from another, the terms do not denote any order or importance. In the drawings, parts of the non-essential components are omitted for the description of the embodiments

[ electric storage device ]

First, a power storage device provided in a power storage module according to the present embodiment will be described. Fig. 1 is a perspective view of an electric storage device 1. Fig. 2 (a) is a schematic diagram of the power storage device 1 as viewed from the axial direction a. Fig. 2 (B) is a schematic diagram of the power storage device 1 as viewed from the second direction C. In fig. 2 (B), the inside of the film package 4 is also illustrated for convenience of explanation. In the present embodiment, the direction in which the axis of the electrode body 2 (the central axis of the cylinder) extends is referred to as the axial direction a, the direction in which the plurality of electrode bodies 2 are arranged is referred to as the first direction B, and the direction intersecting the axial direction a and the first direction B is referred to as the second direction C. As an example, the axial direction a, the first direction B, and the second direction C are orthogonal to each other.

The power storage device 1 of the present embodiment is a chargeable secondary battery such as a lithium ion battery, a nickel-hydrogen battery, or a nickel-cadmium battery, or a capacitor such as an electric double layer capacitor. The power storage device 1 includes a plurality of electrode assemblies 2 and a film casing 4. The power storage device 1 of the present embodiment may include 8 electrode assemblies 2, the number of which is not particularly limited, and one or more of which may be used.

Each electrode body 2 has a cylindrical shape, and a first electrode plate in a strip shape and a second electrode plate in a strip shape are laminated with an electrode separator interposed therebetween, and has a winding structure wound in a spiral shape. As one example, the first electrode plate is a negative electrode plate and the second electrode plate is a positive electrode plate. The power storage device 1 has a plurality of electrode leads electrically connected to the electrode assemblies 2. Specifically, the first electrode lead 8 is electrically connected to the first electrode plate. Further, the second electrode lead 10 is electrically connected to the second electrode plate. For example, the first electrode lead 8 and the second electrode lead 10 are each in a strip shape (rectangular shape having a long direction), and one end of each is welded to each electrode plate. The plurality of electrode bodies 2 are aligned in the first direction B at predetermined intervals so that the axial directions a of the electrode bodies 2 are parallel to each other. The plurality of electrode units 2 are surrounded by a common film casing 4.

The film package 4 has a structure in which two laminated films are laminated, for example. Each laminate film has a structure in which thermoplastic resin sheets are laminated on both surfaces of a metal sheet such as aluminum. The film package 4 further includes a plurality of storage portions 12 and a sealing portion 14. The plurality of receiving portions 12 are arranged at predetermined intervals in the first direction B. Each of the accommodating portions 12 has a cylindrical shape, and accommodates each of the electrode bodies 2. Each of the accommodating portions 12 is constituted by a pocket portion provided in the film outer case 4. The bag portion is a portion where the two laminated films are separated from each other. Therefore, each of the accommodating portions 12 protrudes in the thickness direction (second direction C) of the film package 4 along the shape of the side surface of the electrode body 2, more than the sealing portion 14. Each of the storage sections 12 stores an electrolyte 16 together with the electrode body 2.

The sealing portion 14 seals each housing portion 12 around the outer periphery of each housing portion 12. The sealing portion 14 is constituted by, for example, a welded portion of thermoplastic resin sheets. The welded portion is obtained by subjecting the outer periphery of the bag portion of the film package 4 to a heat-press bonding process, and welding the thermoplastic resin sheets of the two laminated films to each other. The sealing portion 14 seals each of the accommodating portions 12 and connects the plurality of accommodating portions 12 to each other. The seal portion 14 includes a pair of first portions 14a arranged to sandwich the respective housing portions 12 in the axial direction a and extending in the first direction B, and a plurality of second portions 14B alternately arranged with the plurality of housing portions 12 in the first direction B and extending in the axial direction a. The end portions of the second portions 14b in the axial direction a are connected to the first portions 14a. Each housing 12 is sealed at an end in the axial direction a by a pair of first portions 14a and at an end in the first direction B by a pair of second portions 14B. The number of the seal portions 14 to be fitted to the housing portions 12 may be one or more.

The ends of the first electrode lead 8 and the second electrode lead 10 opposite to the side connected to the electrode body 2 protrude from the sealing portion 14 to the outside. The interface between each electrode lead and the film casing 4 is sealed with a known sealant. In the present embodiment, the first electrode lead 8 and the second electrode lead 10 connected to each electrode body 2 protrude to opposite sides in the axial direction a. Further, each of the first electrode leads 8 protrudes to the same side.

Next, an example of a manufacturing method of the power storage device 1 is shown. Fig. 3 (a) to 3 (E) are process drawings of a method for manufacturing the power storage device 1. First, as shown in fig. 3 (a), a first laminate film 20a is prepared. A plurality of semi-cylindrical pits 18 are formed in advance on the first laminated film 20a. The plurality of dimples 18 are formed by, for example, subjecting the first laminated film 20a to a known process such as press working. The electrode body 2 is placed in each of the recesses 18. The first electrode lead 8 and the second electrode lead 10 are connected to the electrode body 2 in advance. A sealing agent (not shown) is provided in the first electrode lead 8 and the second electrode lead 10.

Next, as shown in fig. 3 (B), the second laminated film 20B is overlapped with the first laminated film 20a, and the film package 4 is formed. In the second laminated film 20b, semi-cylindrical dimples 18 are provided at positions of the first laminated film 20a facing the respective dimples 18. Accordingly, the first laminated film 20a and the second laminated film 20b overlap, so that the accommodating portion 12 is formed by the pair of dimples 18. The method of forming the pits 18 in the second laminated film 20b is the same as the method of forming the pits 18 in the first laminated film 20a. In a state where the electrode body 2 is accommodated in the accommodating portion 12, the distal ends of the first electrode lead 8 and the second electrode lead 10 protrude outward of the film casing 4.

Next, as shown in fig. 3 (C), a part of the film package 4 is subjected to a thermocompression bonding process to form a welded portion 22. The portion where the thermocompression bonding process of the film outer body 4 is not performed becomes the non-welded portion 24. The non-welded portion 24 is disposed so as to connect the housing portions 12 to the outside of the film package 4. In the present embodiment, the non-welded portion 24 is provided so as to connect the edge of the four sides of each of the storage portions 12 from which the first electrode lead 8 protrudes and the outside of the film package 4. The remaining three sides of each receiving portion 12 are enclosed by the welded portion 22. The interface between the film casing 4 and the second electrode lead 10 is sealed with a sealant.

Next, as shown in fig. 3 (D), the electrolyte 16 is injected into each of the accommodating portions 12 through the non-welded portions 24. After the electrolyte 16 is injected, as shown in fig. 3 (E), the non-welded portion 24 is also subjected to a thermocompression bonding process. As a result, the seal portion 14 is formed around the entire circumference of each housing portion 12. The interface between the film casing 4 and the first electrode lead 8 is sealed with a sealant. Through the above steps, the power storage device 1 is obtained.

The method for manufacturing the power storage device 1 is not limited to the above method. For example, a laminated film having twice the length of the power storage device 1 may be used, and the laminated film may be folded in half to cover each electrode body 2. When the amount of the electrolyte 16 required is small, the electrolyte 16 is impregnated into the electrode spacer in advance, and the step of injecting the electrolyte 16 shown in fig. 3 (D) can be omitted. At this time, in the thermocompression bonding step shown in fig. 3 (C), thermocompression bonding is performed on the entire circumference of each housing portion 12, thereby forming the sealing portion 14.

[ electric storage Module ]

The power storage device 1 is mounted to the power storage module 100 of the present embodiment. Fig. 4 is a perspective view of power storage module 100 according to the embodiment. Fig. 5 is an exploded perspective view of the power storage module 100. In fig. 4 and 5, the reinforcing plate 128 is not illustrated. The power storage module 100 includes the power storage device 1 and a holder 104. The power storage module 100 of the present embodiment includes a plurality of power storage devices 1 and a plurality of holders 104. The illustrated power storage module 100 includes 8 power storage devices 1, but the number thereof is not particularly limited.

The plurality of power storage devices 1 are aligned in the second direction C with the storage units 12 aligned in the first direction B to determine the posture. Two power storage devices 1 adjacent to each other in the second direction C are arranged offset from each other in the first direction B so that the axial centers of the electrode bodies 2 of the other power storage device 1 are located between the axial centers of the two electrode bodies 2 adjacent to each other in the one power storage device 1. That is, between the valleys of the two storage units 12 of one power storage device 1, the storage unit 12 of the other power storage device 1 is fitted. Thereby, the size of the power storage module 100 in the second direction C can be reduced.

The plurality of holders 104 are alternately arranged with the plurality of power storage devices 1 in the second direction C. The cage 104 extends in the first direction B (i.e., is long in the first direction B). The power storage device 1 and the holder 104 are mounted in the second direction C, so that the power storage device 1 is held by the holder 104. This can improve the rigidity of the power storage device 1. The holder 104 as one example is composed of a metal such as aluminum, aluminum alloy, steel, or the like. This can provide the holder 104 with desired rigidity and thermal conductivity. The holder 104 may be made of resin if it has rigidity and thermal conductivity equal to or higher than a predetermined value. The power storage module 100 further includes a filler 106 interposed between the power storage device 1 and the holder 104. The filler 106 will be described in detail later.

Further, the power storage module 100 has a pair of end plates 108. The plurality of power storage devices 1 and the plurality of holders 104 alternately stacked in the second direction C are restricted by the pair of end plates 108. The power storage module 100 is fixed to a battery pack (not shown) by screw fastening or the like via the end plate 108.

The power storage module 100 further includes a bus bar 110 (collector plate) electrically connecting the plurality of electrode leads. The first electrode lead 8 and the second electrode lead 10 of each power storage device 1 are electrically connected to the bus bar 110, and the plurality of power storage devices 1 are electrically connected to each other. For example, each electrode lead is bonded to the bus bar 110 by a known bonding process such as laser welding. The electrical connection method of each electrode assembly 2 and the electrical connection method of each power storage device 1 are not particularly limited. In each power storage device 1, a plurality of electrode units 2 may be connected in series, may be connected in parallel, or may be connected in series and in parallel in combination. The plurality of power storage devices 1 may be connected in series, may be connected in parallel, or may be connected in series and in parallel in combination.

Further, the power storage module 100 includes a plurality of insulating members 112 extending in the first direction B. Each insulating member 112 has a support plate 114 and a cover 116. The support plate 114 and the cover 116 extend in the first direction B. The bus bar 110 is surrounded by a support plate 114 and a cover 116. As for the insulating member 112, it will be described in detail later.

Fig. 6 is a perspective view of power storage device 1 and holder 104 arranged in second direction C. Fig. 7 (a) and 7 (B) are cross-sectional views taken along a plane perpendicular to the axial direction a of a part of the power storage module 100. Fig. 8 (a) is an enlarged view of a part of the filler 106. Fig. 8 (B) is an enlarged view of the dotted line area in fig. 7 (a). In fig. 7 (a), 7 (B) and 8 (B), the interior of the housing 12 is not shown.

As shown in fig. 6, the holder 104 of the present embodiment is plate-shaped extending in the first direction B. The holder 104 has a plurality of concave portions 118 aligned in the first direction B, and a plurality of flat portions 120 connecting the concave portions 118 adjacent to each other. The holder 104 of the present embodiment is in the shape of a wave plate in which the irregularities are repeated in the first direction B. That is, the plurality of concave portions 118 and the plurality of flat portions 120 are alternately arranged in the first direction B as viewed from either main surface side. The flat portion 120 on one main surface side constitutes a bottom portion 118a of the concave portion 118 on the other main surface side (see fig. 7 (a) and the like).

Accordingly, each of the storage units 12 of the power storage device 1 on both sides of the arrangement of the holders 104 can be fitted into the holder 104. This can further improve the stability of each power storage device 1 in power storage module 100. The holder 104 having such a structure can be formed by press working a single metal plate, for example. The holder 104 may be a plate material having a thickness such that the bottom 118a of the recess 118 on one main surface side does not protrude further toward the other main surface than the bottom 118a of the recess 118 on the other main surface side. That is, in the thickness direction (second direction C) of the holder 104, the extension of the concave portion 118 provided on one main surface and the extension of the concave portion 118 provided on the other main surface may not overlap.

[ Filler ]

Each concave portion 118 may have a groove shape elongated in the axial direction a. In a state before the power storage device 1 and the holder 104 are mounted, the filler 106 is coated on the wall surface of each recess 118. After the power storage device 1 and the holder 104 are mounted, each housing portion 12 is fitted into each recess 118. As a result, as shown in fig. 7 (a) and 7 (B), the filler 106 is crushed and deformed by the accommodating portion 12 and the concave portion 118, and spreads over the space between the accommodating portion 12 and the concave portion 118.

The distance between the recess 118 formed by the bottom 118a and the pair of inclined portions 118b, which will be described later, and the housing 12 having a substantially circular cross section varies depending on the position. In particular, the boundary portions of the bottom portion 118a and the inclined portion 118b are farthest from the accommodating portion 12. The filler 106 is disposed at least between the boundary between the bottom portion 118a and the inclined portion 118b and the accommodating portion 12. In this boundary portion, the filler 106 can be filled more than in other portions. By filling the filler 106 in the recess 118 having a plurality of flat surfaces in this manner, the space of the recess 118 can be increased without exceeding the necessity, and the filling amount of the filler 106 can be locally increased. This allows efficient heat absorption by the power storage device 1. Furthermore, the filler 106 may also be interposed between the flat portion 120 and the sealing portion 14, more specifically between the flat portion 120 and the second portion 14 b. With this configuration, the filling amount of the filler 106 between the pair of holders 104 can be increased. In addition, when the filler 106 has adhesiveness, the fixing strength between the power storage device 1 and the holder 104 can be improved. Further, since the contact area between holder 104 and filler 106 increases, heat release from power storage device 1 to holder 104 can be promoted. Further, the filler 106 may cover the end face of the accommodating portion 12 in the axial direction a. The filler 106 covering the end face of the storage unit 12 can protect the end face of the storage unit 12 from the emissions such as the gas post-flame emitted from the other power storage device 1.

The filler 106 of the present embodiment has thixotropic properties. Thixotropic refers to a property in which the viscosity is reduced by stress and becomes liquid, and the viscosity rises to become solid when left to stand. The filler 106 preferably has an initial viscosity (or initial viscosity) of 10,000 mPas or more. Since filler 106 has thixotropic properties, filler 106 is easily maintained in shape on the wall surface of recess 118 in the state before power storage device 1 and holder 104 are mounted. This suppresses the filler 106 from falling from the recess 118. On the other hand, when the power storage device 1 and the holder 104 are mounted, the filler 106 is subjected to stress and is easily deformed. This facilitates filling of filler 106 between accommodating portion 12 and recess 118 without any gap.

In addition, the filler 106 has a property that the thermal conductivity at a first temperature is lower than the thermal conductivity at a second temperature lower than the first temperature. That is, the thermal conductivity of the filler 106 decreases when the temperature increases. The first temperature is, for example, a temperature at which each electrode body 2 falls into an abnormal state, and is, for example, 100 ℃ or higher. The second temperature is, for example, a temperature at which each electrode body 2 is in a normal state, in other words, a temperature at which a charge/discharge state of each electrode body 2 is within a designed range, for example, a temperature of-30 ℃ to 60 ℃. The thermal conductivity of the filler 106 at the first temperature is preferably 0.1W/m·k or less, and the thermal conductivity of the filler 106 at the second temperature is preferably 0.5W/m·k or more. The difference between the thermal conductivity at the first temperature and the thermal conductivity at the second temperature is preferably 0.5W/mK or more. The first temperature and the second temperature, and the thermal conductivity at each temperature can be appropriately set based on experiments or simulations performed by a designer.

When each electrode body 2 is in a normal state and the filler 106 is at the second temperature, the filler 106 promotes heat transfer from each electrode body 2 to the holder 104 by its own thermal conductivity, as shown in fig. 7 (a). Preferably, the thermal conductivity of the cage 104 is higher than the thermal conductivity of the filler 106 at the second temperature. According to this configuration, when the temperature of the power storage device 1 in the normal state increases, heat can be rapidly diffused into the power storage module 100 via the filler 106 and the holder 104. On the other hand, when each electrode body 2 is brought into an abnormal state and the filler 106 has a first temperature, as shown in fig. 7 (B), the thermal conductivity of the filler 106 is low, and heat transfer from each electrode body 2 to the holder 104 is suppressed. Preferably, the thermal conductivity of filler 106 decreases reversibly. In addition, the filler 106 reaching the first temperature may also have some heat transfer properties. At this time, the heat of the electrode body 2 in the abnormal state can be diffused through the holder 104.

As the composition of the filler 106 whose thermal conductivity varies according to temperature and has thixotropic properties as described above, an example is shownEthane or silicon is used as a main agent, and a metal hydroxide component is blended. The metal hydroxide is desirably contained in an amount of 50 to 90% by mass based on the total mass of the materials constituting the filler 106. The metal hydroxide liberates water vapor by thermal decomposition if it is further subjected to high temperatures. Thus, the metal hydroxide plays a role of heat absorption, and changes to a metal oxide having heat resistance and insulation. Further, the main material such as ethane or silicon is decomposed and volatilized by high temperature, and a porous structure of the metal oxide is formed, thereby exhibiting an adiabatic effect. That is, the thermal conductivity is greatly reduced. It is also considered that the metal oxide having a porous structure formed by the heating to 800 ℃ or higher due to thermal runaway of the battery can maintain the heat insulation property even at such a high temperature. As such a metal hydroxide, aluminum hydroxide (Al (OH) is exemplified ₃ ) Magnesium hydroxide (Mg (OH) ₂ ) Calcium hydroxide (Ca (OH) ₂ ) Zinc hydroxide (Zn (OH) ₂ ) Ferric hydroxide (Fe (OH)) ₂ ) Manganese hydroxide (Mn (OH) ₂ ) Zirconium hydroxide (Zr (OH) ₂ ) Gallium hydroxide (Ga (OH) ₃ ). For example, in the case of aluminum hydroxide, it is decomposed into about 66% of Al by dehydration at 200℃or higher ₂ O ₃ With about 34% water vapor, an endothermic reaction is exhibited. By this reaction, the heat generated by the battery cell that has undergone thermal runaway is absorbed, and the amount of heat transferred to the holder 104 can be reduced. Further, thereafter, the main material is decomposed by high temperature and volatilized, whereby the porous alumina exhibits an adiabatic effect.

As shown in fig. 8 (a), the filler 106 of the present embodiment may contain a plurality of hollow glass beads 122. The hollow glass beads 122 have higher flame resistance than the constituent materials of the filler 106. Therefore, even when the constituent material of the filler 106 burns out, the hollow glass beads 122 are likely to remain between the accommodating portion 12 and the concave portion 118. The remaining hollow glass beads 122 can prevent the thermal connection between the holder 104 and the housing 12 of the electrode body 2 which is in an abnormal state. In addition, the hollow glass beads 122 are light because they are hollow. Accordingly, the power storage module 100 can be reduced in weight.

[ adhesive ]

As shown in fig. 6, each flat portion 120 extends parallel to the sealing portion 14. In a state before the power storage device 1 and the holder 104 are mounted, the adhesive 124 is applied to each flat portion 120. As the adhesive 124, a known insulating adhesive or the like can be used. After the power storage device 1 and the holder 104 are mounted, the second portions 14b of the sealing portions 14 and the flat portions 120 are pressed against each other. As a result, as shown in fig. 8 (B), the adhesive 124 is deformed by the second portion 14B and the flat portion 120 being crushed, and a layer of the adhesive 124 is formed between the second portion 14B and the flat portion 120. Holder 104 is bonded to sealing portion 14 by adhesive 124, and holds power storage device 1. This can improve the rigidity of the power storage device 1.

Further, at least a part of the power storage device 1 is sandwiched by two holders 104 adjacent to each other. At this time, each second portion 14b is sandwiched by the pair of flat portions 120 in the second direction C. Each flat portion 120 is bonded to the second portion 14b by an adhesive 124. This can further improve the rigidity of the power storage module 100. The adhesive 124 preferably has thixotropic properties similar to the filler 106. The adhesive 124 may have a property of decreasing thermal conductivity as the temperature increases, similar to the filler 106.

[ honeycomb Structure ]

As shown in fig. 7 (a) and 7 (B), each concave portion 118 of the present embodiment has a trapezoidal columnar shape, in other words, a cross section orthogonal to the axial direction a has a trapezoidal shape. That is, each concave portion 118 has a bottom portion 118a extending in the first direction B, and a pair of inclined portions 118B extending obliquely from both ends of the bottom portion 118a in the first direction B. Since the pair of inclined portions 118b have the same length and angle with respect to the bottom portion 118a, each concave portion 118 has an isosceles trapezoid pillar shape. The end of each inclined portion 118b opposite to the bottom portion 118a is connected to the flat portion 120. Thus, each inclined portion 118b connects the bottom portion 118a and the flat portion 120. Two holders 104 adjacent to each other in the second direction C are stacked so that the inner spaces of the respective concave portions 118 face each other. Thereby, a plurality of hexagonal prism-shaped spaces are formed around each of the accommodating portions 12. The power storage module 100 has a plurality of spatially arranged honeycomb structures in a hexagonal prism shape. This can further improve the rigidity of the power storage module 100.

[ claw and reinforcing plate ]

Fig. 9 (a) is a perspective view of a part of the holder 104. Fig. 9 (B) is a top view of a part of the holder 104. Fig. 10 (a) is a perspective view of the power storage module 100. Fig. 10 (B) is a cross-sectional view taken along a plane perpendicular to the second direction C of a part of the power storage module 100. As shown in fig. 9 (a) and 9 (B), the holder 104 of the present embodiment has a plurality of claw portions 126 at the end in the axial direction a of the holder 104. Each claw portion 126 is bent toward the adjacent power storage device 1, and extends in a direction intersecting the axial direction a. Each claw portion 126 plugs an end portion in the axial direction a in the inner space of the recess 118.

The holder 104 of the present embodiment has a claw portion 126 (see fig. 6) at only one end portion in the axial direction a. Further, the two holders 104 adjacent to each other determine the posture in such a manner that the ends provided with the claw portions 126 are opposite to each other. Therefore, when the power storage module 100 is viewed from the axial direction a, the rows of the claw portions 126 extending in the first direction B are arranged at intervals in the second direction C.

In addition, in fig. 6, 9 (a) and 9 (B), two claw portions 126 having different shapes are provided for one concave portion 118, but the present invention is not limited to this configuration, and three or more claw portions 126 may be provided for one concave portion 118. Further, a claw portion 126 having the same shape or a similar shape as the shape of the concave portion 118 as viewed from the axial direction a may be provided. Further, a notch may be provided at a portion where the holder 104 is bent, for example, at a boundary between the bottom portion 118a and the inclined portion 118b or at a boundary between the concave portion 118 and the claw portion 126. By this notch, processing at the time of forming the bottom portion 118a and the inclined portion 118b, or processing at the time of forming the claw portion 126 becomes easy.

As shown in fig. 10 (a) and 10 (B), the power storage module 100 of the present embodiment includes a pair of reinforcing plates 128. The reinforcing plate 128 as one example is made of a metal such as aluminum, aluminum alloy, steel, or the like; thermoplastic resins such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), and Noryl (registered trademark) resin (modified PPE); and Fiber Reinforced Plastics (FRP) including Carbon Fiber Reinforced Plastics (CFRP) and Glass Fiber Reinforced Plastics (GFRP).

The pair of reinforcing plates 128 sandwich a laminate including the plurality of power storage devices 1, the plurality of holders 104, and the pair of end plates 108 in the axial direction a. Each end plate 108 can be fixed to the laminate by a known fixing method. Thus, the stiffener 128 is directly or indirectly connected to the plurality of retainers 104. The reinforcing plate 128 of the present embodiment is supported by a plurality of claw portions 126. That is, the claw portion 126 is used as a support structure for the reinforcing plate 128. The reinforcing plate 128 of the present embodiment has a plurality of ribs 130 arranged at predetermined intervals in the first direction B. Each rib 130 is provided on the main surface facing the opposite side of the laminate of reinforcing plates 128, and extends in the second direction C, which is the lamination direction of power storage device 1 and holder 104. Further, grooves extending in the second direction C are provided on the surface of the laminate facing each rib 130.

By providing the reinforcing plate 128 in the laminate, the rigidity of the power storage module 100 can be improved. Further, heat of each power storage device 1 is transferred to reinforcing plate 128, whereby each power storage device 1 can be cooled. Further, by connecting or incorporating cooling pipes to the reinforcing plate 128, the cooling efficiency of the power storage device 1 can be further improved. In addition, when the temperature of the electrode body 2 excessively increases and gas is ejected from the housing 12 or flame is generated from the gas, diffusion of the gas or flame can be suppressed. This can suppress the burn-up in the other housing portion 12.

Further, the reinforcing plate 128 has the rib 130, so that the rigidity of the reinforcing plate 128 and thus the power storage module 100 can be further improved. The grooves provided in the ribs 130 may also function as conduits through which the gas ejected from the respective storage portions 12 flows. The stiffening plate 128 may be a single plate or may not have the rib 130.

Diffusion of the gas or flame ejected from the housing 12 is also suppressed by the claw portion 126. That is, the gas or flame is prevented from diffusing by the claw portion 126 overlapping the housing portion 12 for ejecting the gas or flame in the axial direction a. If the reinforcing plate 128 is not provided, the gas or flame ejected from the housing 12 passes through the gap between the claw portions 126 or the claw portions 126 breaks up, and reaches the battery pack (not shown). When the battery pack is rebounded, the rebounded gas or flame can be prevented from reaching the other accommodating portion 12 by the claw portion 126 overlapping the other accommodating portion 12 in the axial direction a.

[ insulating Member ]

Fig. 11, 12 (a) and 12 (B) are perspective views of a part of the power storage module 100. Fig. 13 is a cross-sectional view taken along a plane perpendicular to first direction B of a portion of power storage module 100. In fig. 11, a state in which a part of the insulating member 112 is removed is illustrated. In fig. 12 (a), the cover 116 is shown removed.

The power storage module 100 includes the insulating member 112 as described above. The insulating member 112 has a support plate 114 and a cover 116. As shown in fig. 11, the insulating member 112 is placed on the end of the holder 104 on the side not having the claw portion 126. Therefore, when the power storage module 100 is viewed from the axial direction a, the rows of the claw portions 126 extending in the first direction B are alternately arranged with the insulating member 112 in the second direction C. The insulating member 112 is made of, for example, a resin having insulating properties. As the resin constituting the insulating member 112, thermoplastic resins such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), noryl (registered trademark) resin (modified PPE), and the like are exemplified; fiber Reinforced Plastics (FRP) including Carbon Fiber Reinforced Plastics (CFRP) and Glass Fiber Reinforced Plastics (GFRP) and the like.

As shown in fig. 12 (a), first, the support plate 114 is placed on the holder 104. The bus bar 110 is mounted on the support plate 114. The electrode wires of the two power storage devices 1 arranged with the bus bar 110 interposed therebetween are bonded to the bus bar 110 on the support plate 114 as viewed in the axial direction a. As shown in fig. 12 (B), the cover 116 is attached to the support plate 114. Thereby, the bus bar 110 on the support plate 114 is covered by the cover 116. The cover 116 is fixed to the support plate 114 by a known fixing method such as engagement with a click. The cover 116 includes a plurality of protruding portions 116a protruding toward the holder 104, more specifically, toward the inner space of the recess 118, as viewed in the axial direction a.

As shown in fig. 13 (a), the insulating member 112 is interposed between the plurality of electrode leads and the holder 104. Specifically, the support plate 114 is interposed between the holder 104, on which the insulating member 112 is mounted, the first electrode lead 8, and the second electrode lead 10. Further, a support plate 114 is interposed between the holder 104 and the bus bar 110. On the other hand, the protruding portion 116a of the cover 116 is located below the claw portion 126 of the holder 104 adjacent to the holder 104 on which the insulating member 112 is mounted. Thereby, the lid 116 is also interposed between the claw portion 126 and the first electrode lead 8 and the second electrode lead 10. Further, the cover 116 is interposed between the claw 126 and the bus bar 110. This suppresses the electrical connection, i.e., insulation, between the electrode leads and the bus bars 110 and the holder 104. The protruding portion 116a and the claw portion 126 also have a function of shielding the gas or flame ejected from the housing portion 12.

As described above, the power storage module 100 of the present embodiment includes the holder 104 that holds the power storage device 1. The rigidity of the power storage module 100 can be improved by holding the power storage device 1 by the holder 104. Further, each electrode body 2 can be cooled by the heat absorption action of the holder 104.

The power storage module 100 further includes a filler 106 interposed between the power storage device 1 and the holder 104. The gaps between the power storage device 1 and the holder 104 are filled with the filler 106, and heat conduction from each electrode body 2 to the holder 104 can be promoted. In addition, each electrode body 2 can be cooled by the endothermic action of the filler 106 itself. Further, the posture of the power storage device 1 can be stabilized. Therefore, the electrically connected state between each power storage device 1 and bus bar 110 can be maintained more stably, and breakage or the like of each power storage device 1 can be further suppressed. Therefore, the power generation performance or safety of the power storage module 100 can be improved.

The filler 106 has a property of decreasing thermal conductivity when the temperature increases. Thus, when each electrode body 2 is in a normal state, heat of each electrode body 2 can be positively transferred to the holder 104 via the filler 106. As a result, the temperature bias between the electrode assemblies 2 can be reduced in the entire power storage module 100. When each electrode body 2 is brought into an abnormal state and reaches the first temperature, the movement of heat from each electrode body 2 to the holder 104 can be suppressed by the filler 106. As a result, thermal runaway-linked diffusion of the electrode body 2 to other electrode bodies 2 can be suppressed.

Therefore, according to the power storage module 100 of the present embodiment, both cooling of the electrode assembly 2 at normal times and suppression of heat diffusion at abnormal times can be achieved, and the safety of the power storage module 100 can be improved. The effect of the filler 106 described above can be enjoyed not only in the case where the power storage device 1 in which the plurality of electrode units 2 are sealed by the film package 4 is held by the holder 104, but also in the case where the plurality of power storage devices in which the respective electrode units 2 are housed in the package can are held by the holder 104.

The filler 106 of the present embodiment contains hollow glass beads 122. This can reduce the weight of the filler 106 and thus the power storage module 100. Further, the heat insulating effect of the filler 106 when the electrode body 2 is in an abnormal state can be easily maintained. The filler 106 of the present embodiment has thixotropic properties. This can improve the ease of mounting the power storage module 100. Further, the reliability and yield in manufacturing the power storage module 100 can be improved.

The power storage device 1 of the present embodiment has a bag structure in which a plurality of electrode units 2 are accommodated in a film casing 4. This allows the power storage module 100 to be lighter than if each electrode body 2 were sealed by the outer can alone. The number of electrode assemblies 2 and storage units 12 included in power storage device 1 may be one. The holder 104 of the present embodiment is bonded to the sealing portion 14 of the power storage device 1, and holds the power storage device 1. Power storage device 1 is long in first direction B, and film casing 4 has high flexibility. Therefore, the power storage device 1 is easily flexible. In contrast, by adhering holder 104 to sealing portion 14, power storage device 1 can be held more stably. Therefore, the rigidity of the power storage module 100 can be improved, and therefore the safety of the power storage module 100 can be improved. Further, by increasing the rigidity, the thickness of the holder 104 can be easily reduced, and thus further weight reduction of the power storage module 100 can be expected.

In addition, in at least a part of power storage device 1, holders 104 are bonded to both sides of sealing portion 14. This can further improve the rigidity of the power storage module 100. In the present embodiment, the hexagonal-prism-shaped space accommodating each accommodating portion 12 is filled, and a honeycomb-shaped power storage device holding structure is formed. This can further improve the rigidity of the power storage module 100.

The holder 104 of the present embodiment includes a plurality of claw portions 126, and a part of each hexagonal space is closed by the claw portions 126 when viewed from the axial direction a. This can reduce the risk of damaging other storage units 12 by diffusing gas or flame when the gas or flame is ejected from each storage unit 12. Therefore, the safety of the power storage module 100 can be further improved. The power storage module 100 of the present embodiment further includes a reinforcing plate 128 connected to the holder 104. This can improve the rigidity of the power storage module 100 and improve the heat release performance of each power storage device 1. When the gas or flame is ejected from each housing portion 12, the flame can be prevented from being spread to other housing portions 12.

The power storage module 100 of the present embodiment further includes an insulating member 112 interposed between the plurality of electrode leads and the holder 104. This can suppress the short circuit between the two, and further improve the power generation performance and safety of the power storage module 100. Further, a part of the hexagonal-prism-shaped space is plugged by the insulating member 112 as viewed from the axial direction a. Therefore, when the gas or flame is ejected from each housing portion 12, the flame can be prevented from being spread to other housing portions 12. In the present embodiment, the bus bar 110 is placed on the support plate 114 and covered with the cover 116. This can suppress a short circuit between the bus bar 110 and the holder 104, and further improve the power generation performance and safety of the power storage module 100. Further, since the insulating member 112 is used as a support member for the bus bar 110, the number of components of the power storage module 100 can be reduced.

The embodiments of the present disclosure are described above in detail. The foregoing embodiments merely illustrate specific examples of when implementing the disclosure. The content of the embodiment does not limit the technical scope of the present disclosure, and various design changes such as modification, addition, and deletion of the constituent elements can be made without departing from the spirit of the invention defined in the claims. The new embodiment with the design changed has the effects of both the combined embodiment and the modification. In the foregoing embodiments, the expressions such as "present embodiment" and "in the present embodiment" are given emphasis on what can be such design changes, and design changes are permitted even without such expressions. Any combination of the constituent elements included in each embodiment is also effective as an aspect of the present disclosure. The hatching for the cross section of the drawing is not limited to the material of the hatched object.

The invention of the above embodiment can be also specified by the following items.

(item 1)

An electricity storage module (100) is provided with:

power storage device (1)

A holder (104) for holding the power storage device (1);

The power storage device (1) has a cylindrical electrode body (2), and a film casing (4) having a housing portion (12) that encloses the electrode body (2), and a sealing portion (14) that seals the housing portion (12),

the holder (104) is bonded to the sealing portion (14).

(item 2)

The electricity storage module (100) according to item 1,

the power storage device (1) has a plurality of electrode bodies (2), and a plurality of storage units (12) each for housing the plurality of electrode bodies (2),

the sealing part (14) seals each of the accommodating parts (12) and connects the plurality of accommodating parts (12) to each other.

(item 3)

The power storage module (100) according to item 2, comprising:

a plurality of power storage devices (1) arranged in a first direction (B) in which a plurality of electrode bodies (2) are arranged and a second direction (C) intersecting with an axial direction (A) of the electrode bodies (2),

a plurality of holders (104) alternately arranged with the plurality of power storage devices (1) in the second direction (C);

two retainers (104) adjacent to each other sandwich the sealing portion (14), and are adhered to the sealing portion (14), respectively.

(item 4)

The electricity storage module (100) according to item 3,

each holder (104) has a plate shape extending in a first direction (B), and comprises: a plurality of trapezoidal columnar recesses (118) arranged in a first direction (B), each of the accommodating portions (12) being embedded therein; a plurality of flat portions (120) which connect the recesses (118) adjacent to each other and are bonded to the sealing portion (14),

The power storage module (100) has a honeycomb structure in which a plurality of hexagonal prism-shaped spaces surrounding the housing portion (12) are arranged.

(item 5)

The power storage module (100) according to any one of items 1 to 4,

the holder (104) has a plurality of claw portions (126) bent toward the adjacent power storage device (1) at the end in the axial direction (A) of the electrode body (2).

(item 6)

The electricity storage module (100) according to item 5,

the claw portion (126) overlaps the housing portion (12) as viewed from the axial direction (A).

(item 7)

The power storage module (100) according to any one of items 1 to 6,

a reinforcing plate (128) connected to the retainer (104) is provided.

(item 8)

The electricity storage module (100) according to item 7,

the reinforcing plate (128) has ribs (130) extending in the stacking direction (C) of the power storage device (1) and the holder (104).

(item 9)

The power storage module (100) according to any one of items 1 to 8,

the power storage device (1) has a plurality of electrode bodies (2), and a plurality of electrode leads (8, 10) electrically connected to the respective electrode bodies (2) and protruding from a sealing portion (14),

the power storage module (100) is provided with an insulating member (112) interposed between the plurality of electrode leads (8, 10) and the holder (104).

(item 10)

The electricity storage module (100) according to item 9,

comprising a bus bar (110) electrically connecting a plurality of electrode leads (8, 10),

The insulating member (112) has a support plate (114) on which the bus bar (110) is mounted, and a cover (116) that covers the bus bar (110) on the support plate (114).

(item 11)

The electricity storage module (100) according to item 10,

the cover (116) has a plurality of protruding parts (116 a) protruding toward the holder (104) when viewed in the axial direction (A) of the electrode body (2).

(item 12)

An electricity storage module (100) is provided with:

an electricity storage device (1);

a holder (104) for holding the power storage device (1); and

and a filler (106) interposed between the power storage device (1) and the holder (104) and having a lower thermal conductivity at a first temperature than at a second temperature lower than the first temperature.

(item 13)

The power storage module (100) according to item 12,

the thermal conductivity of the cage (104) is higher than the thermal conductivity of the filler (106) at the second temperature.

(item 14)

The power storage module (100) according to item 12 or 13,

the filler (106) contains hollow glass beads (122).

(item 15)

The power storage module (100) according to any one of items 12 to 14,

the filler (106) has thixotropic properties.

(item 16)

The power storage module (100) according to any one of items 12 to 15,

the power storage device (1) is provided with:

a cylindrical electrode body (2); and

and a film outer case (4) having a housing (12) that houses the electrode body (2), and a sealing portion (14) that seals the housing (12).

(item 17)

The power storage module (100) according to item 16,

the holder (104) is bonded to the sealing portion (14).

(item 18)

The power storage module (100) according to item 17,

the power storage device (1) has a plurality of electrode bodies (2), a plurality of storage units (12) for respectively housing the plurality of electrode bodies (2),

(item 19)

The power storage module (100) according to any one of items 16 to 18,

the filler (106) covers the end face of the accommodating section (12) in the axial direction (A) of the electrode body (2).

(item 20)

The power storage module (100) according to item 18, comprising:

a plurality of power storage devices (1) arranged in a first direction (B) in which a plurality of electrode bodies (2) are arranged and in a second direction (C) intersecting an axial direction (A) of the electrode bodies (2), and

(item 21)

The electricity storage module (100) according to item 20,

each holder (104) is plate-shaped extending in a first direction (B), and comprises: a plurality of trapezoidal columnar recesses (118) juxtaposed in a first direction (B), each accommodating portion (12) being embedded therein; and a plurality of flat portions (120) which connect the recesses (118) adjacent to each other and are bonded to the sealing portion (14)

(item 22)

The electricity storage module (100) according to item 21,

the recess (118) has a bottom (118 a) and an inclined portion (118 b) connecting the bottom (118 a) and the flat portion (120),

the filler (106) is disposed at least between the boundary between the bottom (118 a) and the inclined portion (118 b) and the accommodating portion (12).

(item 23)

The power storage module (100) according to item 21 or 22,

the filler (106) is interposed between the flat portion (120) and the sealing portion (14).

(item 24)

The power storage module (100) according to any one of items 16 to 23,

(item 25)

The power storage module (100) according to item 24,

(item 26)

The power storage module (100) according to any one of items 16 to 25,

a reinforcing plate (128) connected to the retainer (104) is provided.

(item 27)

The power storage module (100) according to item 26,

(item 28)

The power storage module (100) according to any one of items 16 to 27,

the power storage module (100) has an insulating member (112) interposed between a plurality of electrode leads (8, 10) and a holder (104).

(item 29)

The power storage module (100) according to item 28,

(item 30)

The power storage module (100) according to item 29,

Industrial applicability

The present disclosure can be utilized in an electric storage module.

Description of the reference numerals

1 power storage device, 2 electrode body, 4 film package, 12 housing portion, 14 sealing portion, 100 power storage module, 104 holder, 106 filler, 110 bus bar, 112 insulating member, 114 support plate, 116 cover portion, 118 recess portion, 120 flat portion, 122 hollow glass bead, 124 adhesive, 126 claw portion, 128 reinforcing plate.

Claims

1. An electric storage module, comprising:

power storage device

A holder that holds the power storage device;

the power storage device includes: a cylindrical electrode body, and a film exterior body having a housing portion for housing the electrode body and a sealing portion for sealing the housing portion,

the retainer is bonded to the seal portion.

2. The electricity storage module according to claim 1,

the power storage device has a plurality of the electrode bodies, and a plurality of the housing portions that wrap the plurality of the electrode bodies respectively,

the sealing portion seals each of the accommodating portions while connecting the plurality of accommodating portions to each other.

3. The power storage module according to claim 2, comprising:

a plurality of the power storage devices arranged in a first direction in which the plurality of electrode bodies are arranged and a second direction intersecting an axial direction of the electrode bodies, an

A plurality of holders alternately arranged with the plurality of power storage devices in the second direction;

two holders adjacent to each other sandwich the sealing portion and are adhered to the sealing portion, respectively.

4. The power storage module according to claim 3,

each holder is plate-shaped extending in the first direction, and includes: a plurality of trapezoidal columnar recesses arranged in the first direction, each of the accommodating portions being embedded therein; and a plurality of flat portions connecting the concave portions adjacent to each other and adhered to the sealing portion,

The power storage module has a honeycomb structure in which a plurality of hexagonal prism-shaped spaces surrounding the accommodation portion are arranged.

5. The power storage module according to any one of claim 1 to 4,

and a filler interposed between the power storage device and the holder, wherein the thermal conductivity at a first temperature is lower than the thermal conductivity at a second temperature lower than the first temperature.

6. The electricity storage module according to claim 5,

the thermal conductivity of the cage is higher than the thermal conductivity of the filler at the second temperature.

7. The power storage module according to claim 5 or 6,

the filler contains hollow glass beads.

8. The power storage module according to any one of claim 5 to 7,

the filler has thixotropic properties.

9. The power storage module according to any one of claim 5 to 8,

the filler covers an end face of the accommodating portion in an axial direction of the electrode body.

10. The power storage module according to any one of claim 5 to 9,

the power storage device has a plurality of the electrode bodies, and a plurality of the housing portions that respectively wrap the plurality of the electrode bodies,

the sealing part seals each of the accommodating parts and connects the plurality of accommodating parts to each other,

The device comprises:

a plurality of the power storage devices arranged in a first direction in which the plurality of the electrode bodies are arranged and a second direction intersecting an axial direction of the electrode bodies, an

two holders adjacent to each other sandwich the sealing portion and are adhered to the sealing portion respectively,

the electricity storage module has a honeycomb structure in which a plurality of hexagonal prism-shaped spaces surrounding the accommodation portion are arranged,

the concave portion has a bottom portion and an inclined portion connecting the bottom portion and the flat portion,

the filler is disposed at least between the bottom and the boundary of the inclined portion and the accommodating portion.

11. The power storage module according to claim 10,

the filler is interposed between the flat portion and the sealing portion.

12. The power storage module according to any one of claims 1 to 11,

The holder has a plurality of claw portions bent toward the adjacent power storage device side at the end in the axial direction of the electrode body.

13. The power storage module according to claim 12,

the claw portion overlaps the housing portion as viewed in the axial direction.

14. The power storage module according to any one of claims 1 to 13,

has a stiffening plate connected to the cage.

15. The power storage module according to claim 14,

the reinforcing plate has ribs extending in the stacking direction of the power storage device and the holder.

16. The power storage module according to any one of claims 1 to 15,

the power storage device has a plurality of the electrode bodies, and a plurality of electrode leads electrically connected to the respective electrode bodies and protruding from the sealing portion,

the power storage module includes an insulating member interposed between the plurality of electrode leads and the holder.

17. The power storage module according to claim 16,

a bus bar having a plurality of the electrode leads electrically connected,

the insulating member has a support plate on which the bus bar is mounted, and a cover portion that covers the bus bar on the support plate.

18. The power storage module according to claim 17,

The cover portion has a plurality of protruding portions protruding toward the holder when viewed in the axial direction of the electrode body.