JP2024091876A - Power storage device - Google Patents

Abstract

To provide a good power storage device capable of preventing concatenation of overheat state between power storage elements well.SOLUTION: A power storage device 100 includes multiple power storage elements 1, and a cooling part 30 for cooling the power storage elements 1. The cooling part 30 incorporates liquid, and has a heat transmission part 31 placed at least between the power storage elements 1, in contact therewith, and cools the power storage elements 1 by the heat of vaporization of the liquid. In the heat transmission part 31 in contact with the power storage element 1 that generated heat, the power storage element 1 is cooled well by the heat of vaporization when the incorporated liquid evaporates.SELECTED DRAWING: Figure 2

Description

The present invention relates to an energy storage device having multiple energy storage elements.

Chargeable and dischargeable energy storage elements are used in a variety of devices, including mobile phones and automobiles. In particular, vehicles that use electrical energy as a power source, such as electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs), require large amounts of energy and are therefore equipped with large-capacity energy storage devices that include multiple energy storage elements.

In such an energy storage device, if the temperature of one of the energy storage elements rises excessively for some reason, even if it is not under normal use conditions, the heat from this energy storage element will be conducted to the adjacent energy storage element, causing the adjacent energy storage element to heat up. As a result, if the active material of the electrode of an adjacent energy storage element is heated to or above its self-heating temperature, this adjacent energy storage element will also become overheated due to self-heating, which will further heat the adjacent energy storage element, causing a chain reaction in which many energy storage elements will become overheated.

When using energy storage elements with metal cases covered with a resin film, if the energy storage elements overheat, the resin film melts and the metal cases come into contact with each other, promoting heat conduction and making it easy for a chain reaction of overheating to occur. In particular, when the metal case is used as an electrode, or when the metal case has an abnormal electric potential due to some abnormality, it may come into electrical contact with the case of an adjacent energy storage element, causing an abnormal current in the adjacent energy storage element and resulting in an overheating state.

JP 2015-195149 A discloses a technology that prevents heat from one storage element from being transferred to an adjacent storage element.

JP 2015-195149 A

In the electricity storage device of Patent Document 1, the heat transfer between the electricity storage elements is suppressed by the partition members formed from a mica aggregate material.
In recent years, there has been a demand for further increases in the capacity of energy storage elements and energy storage devices. When the capacity of an energy storage element is increased, the energy and heat released from the energy storage element when one of the energy storage elements becomes overheated is also very large. Increasing the thickness of the air layer or partition member between the energy storage elements can improve the thermal insulation, but these methods reduce the energy density of the energy storage device. Therefore, new measures are required that can prevent the chain reaction of overheating between the energy storage elements without reducing the energy density.

The present invention aims to provide an energy storage device that can effectively prevent a chain of overheating conditions between storage elements.

The energy storage device according to the present invention comprises a plurality of energy storage elements and a cooling unit that cools the energy storage elements, and the cooling unit has a heat transfer unit that contains a liquid, is disposed at least between the energy storage elements, and is in contact with the energy storage elements to cool the energy storage elements by the heat of vaporization of the liquid.

According to the present invention, in the heat transfer section that comes into contact with the heated electric storage element, the liquid contained therein absorbs heat from the electric storage element and evaporates, thereby effectively cooling the electric storage element. Since the heat transfer section is disposed at least between the electric storage elements, the conduction of heat to the electric storage element adjacent to the heated electric storage element is suppressed, and when there are three or more electric storage elements, the chain reaction of heat transfer to the adjacent electric storage elements is further suppressed. In other words, the chain reaction of overheating between the electric storage elements is effectively prevented.
In addition, since the liquid is contained within the heat transfer portion, after vaporization, it is liquefied within the heat transfer portion and is reused for cooling the electricity storage elements, thereby efficiently cooling the electricity storage elements.

FIG. 1 is a perspective view of an electricity storage device according to a first embodiment; FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3. 10 is an explanatory diagram for explaining cooling by a cooling unit when an electric storage element generates heat; FIG. FIG. 11 is a perspective view of a cooling section according to a second embodiment. FIG. 11 is an explanatory diagram illustrating a case where internal spaces are connected to each other in the second embodiment. FIG. 11 is a perspective view of a cooling section according to a third embodiment. FIG. 13 is a perspective view of a cooling section according to a fourth embodiment. FIG. 13 is an explanatory diagram illustrating cooling when the burst valve of the central storage element is opened.

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof.
First Embodiment
1 is a perspective view of an energy storage device 1 according to a first embodiment. In the following, a case where the energy storage device 1 is a lithium ion secondary battery will be described, but the energy storage device 1 is not limited to a lithium ion secondary battery.
The energy storage element 1 includes a case 11 having a cover plate 2 and a case body 3, a positive electrode terminal 4, a negative electrode terminal 8, gaskets 6 and 10, a burst valve 20, a current collector, and an electrode assembly (not shown).

The case 11 is made of a metal such as aluminum, an aluminum alloy, or stainless steel, or a synthetic resin, has a rectangular parallelepiped shape, and contains the electrode body and the electrolyte (not shown).

The positive electrode terminal 4 has a shaft portion that passes through the cover plate 2 and a plate portion provided at one end of the shaft portion.
The gasket 6 is made of a synthetic resin such as polyphenylene sulfide (PPS) or polypropylene (PP). The positive electrode terminal 4 is provided so as to penetrate the cover plate 2 while being insulated by covering the inner surface of the plate portion and the shaft portion with the gasket 6.

The negative electrode terminal 8 has an axis that passes through the cover plate 2 and a plate provided at one end of the axis. The inner surface of the plate and the axis of the negative electrode terminal 8 are covered by a gasket 10, and the negative electrode terminal 8 is provided to pass through the cover plate 2 in an insulated state.

The electrode body may be a laminate type having a main body formed into a rectangular parallelepiped shape by alternately stacking a plurality of positive and negative electrode plates with separators interposed therebetween, and a positive electrode tab and a negative electrode tab extending from the main body toward the cover plate 2. The positive electrode tab is connected to the positive electrode terminal 4 via a current collector. The negative electrode tab is connected to the negative electrode terminal 8 via a current collector.
The electrode assembly may be of a wound type obtained by winding a positive electrode plate and a negative electrode plate with a separator interposed therebetween into a flat shape.
The electrode body is preferably a laminated type, which has less swelling (swelling of the exterior body such as a metal case like the case 11 or a pouch case with a laminate structure) associated with charging and discharging. Since the exterior body is less swollen, it is possible to prevent the exterior body from pressing against the heat transfer section 31 during normal use.

The positive electrode plate is a positive electrode active material layer formed on a positive electrode substrate foil, which is a plate-shaped (sheet-shaped) or long strip-shaped metal foil made of aluminum, an aluminum alloy, etc. The negative electrode plate is a negative electrode active material layer formed on a negative electrode substrate foil, which is a plate-shaped (sheet-shaped) or long strip-shaped metal foil made of copper, a copper alloy, etc. The separator is a microporous sheet made of a synthetic resin.
As the positive electrode active material used in the positive electrode active material layer or the negative electrode active material used in the negative electrode active material layer, any known material can be used as long as it is a positive electrode active material or a negative electrode active material capable of absorbing and releasing lithium ions.

_Examples of the positive electrode active material that can be used include polyanion compounds such as _LiMPO4 , _LiM2SiO4 , and _LiMBO3 (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), spinel compounds such as lithium titanate and lithium manganate, and lithium transition metal oxides such as LiMO2 (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.).

Examples of negative electrode active materials include lithium metal, lithium alloys (lithium metal-containing alloys such as lithium-aluminum, lithium-silicon, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and Wood's alloy), as well as alloys capable of absorbing and releasing lithium, carbon materials (e.g., graphite, difficult-to-graphitize carbon, easy-to-graphitize carbon, low-temperature fired carbon, amorphous carbon, etc.), metal oxides, lithium metal oxides (Li ₄ Ti ₅ O ₁₂ , etc.), and polyphosphate compounds.

The rupture valve 20 has a rupture section 200 formed by partially reducing the plate thickness. When the internal pressure of the energy storage element 1 rises, it ruptures along the rupture section 200 to form a tongue-shaped section, which then springs outward to form an opening in the cover plate 2.

FIG. 2 is a perspective view of the power storage device 100 according to this embodiment, and FIG.
The energy storage device 100 includes a plurality of energy storage elements 1, a cooling unit 30 that cools the energy storage elements 1, and a case 40 that houses the energy storage elements 1 and the cooling unit 30. In Fig. 2, three energy storage elements 1 are housed, but the number of energy storage elements 1 is not limited to three.
The case 40 is box-shaped and made of an insulating material such as synthetic resin. The case 40 disposes the energy storage element 1 and the cooling unit 30 at predetermined positions and protects them from impact. The case 40 is provided with external electrode terminals (not shown) for charging with electricity from the outside and discharging electricity to the outside.

The cooling unit 30 may be made of a metal such as aluminum having good thermal conductivity and heat resistance, and may be subjected to an insulating treatment such as forming an insulating film on the surface.
As shown in FIG. 3, the cooling unit 30 includes a plate-shaped heat transfer unit 31, connecting units 32 and 33 that connect the heat transfer units 31, and an internal pressure release valve 34. The two heat transfer units 31 are interposed between the long side surfaces of the adjacent energy storage elements 1, and the two heat transfer units 31 abut against the outer long side surfaces of the energy storage elements 1 at both ends. Here, the long side surface is provided so as to extend upward from the long side of the bottom surface of the energy storage element 1 in FIG. 1, and refers to the side surface having the largest area among the side surfaces. An internal pressure release valve 34 is provided on the upper surface of one of the outer heat transfer units 31. The number of heat transfer units 31 may be provided corresponding to the number of energy storage elements 1. The heat transfer units 31 are interposed between the energy storage elements 1, and are further provided so as to abut against the outer long side surfaces of the energy storage elements 1 at both ends.
The outer heat transfer portion 31 can be omitted. For example, when the number of energy storage elements 1 is five, four heat transfer portions 31 are arranged between the energy storage elements 1, and the four heat transfer portions 31 are connected by the connecting portions 32, 33. The long side of the outer energy storage element 1 abuts against the side of the case 40. Providing the outer heat transfer portion 31 provides better cooling efficiency.

FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.
The internal pressure release valve 34 is a circular groove, and as shown in Fig. 4, the thickness of the bottom of the groove is thinner than the thickness of other parts. The internal pressure release valve 34 is formed by cutting, pressing, etc. When the internal pressure release valve 34 is formed by cutting, a device capable of cutting curved surfaces, such as a three-dimensional NC, is used. When the internal pressure release valve 34 is formed by pressing, it is formed by pressing a stamp using a die having protrusions.

The heat transfer section 31 is hollow, and liquid is contained in the internal space. The liquid is preferably non-flammable, has a large heat of vaporization, is corrosion resistant, and does not generate toxic gases. The liquid preferably contains water. Water is harmless, less corrosive, non-flammable, and highly safe. The liquid may be fluid or gel-like, and may contain refrigerants such as HFC refrigerants and inert gas solutions. The boiling point may be adjusted by mixing water with a component other than water.
The amount of liquid to be stored is set based on the internal volume of the heat transfer section 31 and the connecting sections 32 and 33, the expected heat generation temperature of the energy storage element 1, the volume of the liquid when vaporized, etc., so as not to damage the heat transfer section 31.

The upper portions of one end of the long side surfaces of adjacent heat transfer portions 31 are connected by a connecting portion 32. The connecting portion 32 is hollow and configured so that gas inside the connected heat transfer portions 31 flows through the connecting portion 32.
The lower portions of one end of the long side surfaces of adjacent heat transfer sections 31 are connected by a connecting section 33. The connecting section 33 is hollow and configured so that the liquid in the connected heat transfer sections 31 flows through the connecting section 33.
That is, the internal spaces of the adjacent heat transfer portions 31, the connecting portions 32, and the connecting portions 33 are in communication with each other.

FIG. 5 is an explanatory diagram for explaining cooling by the cooling unit 30 when the energy storage element 1 generates heat.
It is assumed that water W is contained as liquid in the cooling section 30, and the central energy storage element 1 generates heat.
Heat is conducted from the heated energy storage element 1 to the heat transfer parts 31, 31 on both sides, and the water W in the heat transfer parts 31 evaporates ( FIG. 5A ). When the water W evaporates, the heat of vaporization is large, and the energy storage element 1 is rapidly cooled by an endothermic reaction. The amount of water W in the heat transfer parts 31 on both sides of the heated energy storage element 1 decreases due to evaporation.

The water vapor in the heat transfer section 31 flows upward due to thermal convection and passes through the connecting sections 32, 32 to the outer heat transfer section 31, which has a lower temperature (Figure 5B). The water vapor condenses in the outer heat transfer section 31, and the amount of water W in the outer heat transfer section 31 increases.

The water W that increases in the outer heat transfer section 31 flows to the inner heat transfer section 31 through the connecting section 33, and the amount of water in the four heat transfer sections 31 becomes equal (Figure 5C). The circulated water W absorbs heat generated by the energy storage element 1 again, vaporizes, and circulates in the same manner as above.

When water is used as the liquid, it evaporates at 100°C and has a large heat of vaporization, so the heat of the energy storage element 1 can be kept below a hundred or so degrees, which may cause malfunctions. In other words, the energy storage device 100 can rapidly cool the energy storage element 1 in a highly safe state.

The above-described energy storage device 100 includes a plurality of energy storage elements 1 and a cooling unit 30 that cools the energy storage elements 1. The cooling unit 30 includes a heat transfer unit 31 that contains a liquid, is disposed at least between the energy storage elements 1, and is in contact with the long sides of the energy storage elements 1 to cool the energy storage elements 1 by the heat of vaporization of the liquid.

According to the above configuration, the heat transfer section 31 in contact with the electric storage element 1 where heat has been generated removes the heat of vaporization when the liquid contained therein vaporizes, thereby effectively cooling the electric storage element 1. Since the heat transfer section 31 is disposed at least between the electric storage elements 1, the conduction of heat to the electric storage element 1 adjacent to the electric storage element 1 where heat has been generated is suppressed, and further, the chain reaction of heat transfer to the adjacent electric storage elements 1 is suppressed. In other words, the chain reaction of overheating between the electric storage elements 1 is effectively prevented.
The structure for cooling the energy storage elements 1 is simple, and the energy storage elements 1 can be cooled even when a small amount of heat is generated.
Furthermore, since the liquid is contained within the heat transfer section 31, after vaporization, it is liquefied within the heat transfer section 31 and is reused for cooling the energy storage elements 1, thereby efficiently cooling the energy storage elements 1.

In the above-mentioned energy storage device 100, the cooling section 30 has connecting sections 32, 33 that connect the heat transfer sections 31 together so that the internal spaces are connected to each other.

According to the above configuration, in one heat transfer section 31 in contact with the heated energy storage element 1, the liquid is evaporated, and the gas generated flows through the connecting sections 32 and 33 by thermal convection and flows to the other heat transfer section 31. The gas is liquefied in the other heat transfer section 31 and flows to the one heat transfer section 31, and the liquid circulates.
Therefore, the liquid is reused for cooling the electric storage elements 1, and the electric storage elements 1 are cooled efficiently.
Furthermore, the temperature difference between the long side surface of one energy storage element 1 that contacts one heat transfer section 31 and the long side surface that contacts the other heat transfer section 31 is reduced, thereby reducing the temperature difference between the energy storage elements 1. Then, the circulation of gas and liquid reduces the temperature difference between the multiple energy storage elements 1, enabling efficient cooling. Even in the case of low-level heat generation that is not abnormal, the heat transfer section 31 effectively dissipates heat from the energy storage elements 1, reducing the temperature difference between the energy storage elements 1.

In the above-mentioned energy storage device 100, the cooling unit 30 has an internal pressure release valve 34 that releases the internal pressure when the internal pressure of the cooling unit 30 exceeds a predetermined pressure.

According to the above configuration, when a large amount of liquid evaporates and the internal pressure of the cooling unit 30 exceeds a predetermined pressure, the internal pressure release valve 34 opens and the gas is released to the outside. This prevents the cooling unit 30 from expanding due to the gas and pressing against the energy storage element 1. If a flammable gas is present, it is mixed with the gas to prevent ignition.

Even if the electric storage element 1 at the end generates heat, instead of at the center, the heat is absorbed by the heat transfer section 31 in the same manner as described above, and the electric storage element 1 is rapidly cooled. The long side surface of the adjacent electric storage element 1 that faces the heated electric storage element 1 is also rapidly cooled, suppressing heat transfer from the heated electric storage element 1 and preventing a chain reaction of overheating between the electric storage elements.
The structure of the cooling section 30 is not limited to the structure shown in Fig. 3. A connecting section may be provided such that a rectangular tube penetrates through the upper and lower parts of each of the four heat transfer sections 31 at one end in the longitudinal direction.

Second Embodiment
Fig. 6 is a perspective view of a cooling unit 35 according to the second embodiment. In the figure, the same parts as those in Fig. 3 are denoted by the same reference numerals and detailed description thereof will be omitted. The cooling unit 35 includes four heat transfer units 31 and a cooling plate 36.
Unlike the first embodiment in which the four heat transfer parts 31 are connected by the connecting parts 32 and 33, the cooling part 35 has end faces 31a of the four heat transfer parts 31 abutting against the cooling plate 36. As in the first embodiment, the heat transfer parts 31 contain liquid such as water.
The internal spaces of the heat transfer section 31 and the cooling plate 36 may or may not be in communication with each other.

7 is an explanatory diagram of a case where the internal spaces are in communication in this embodiment. The energy storage element 1 is inserted between the heat transfer parts 31, and water W is contained in the heat transfer parts 31 and the cooling plate 36.
When the central energy storage element 1 generates heat, as in the first embodiment, the water in the heat transfer section 31 that contacts the energy storage element 1 absorbs the heat of vaporization from the energy storage element 1 and evaporates, rapidly cooling the energy storage element 1. The amount of water in this heat transfer section 31 decreases. The generated water vapor flows to the other heat transfer sections 31 via the cooling plate 36, and water generated by condensation flows to the heat transfer section 31 with the reduced amount of water. The water also absorbs heat to cool the energy storage element 1, and the generated water vapor circulates as described above. The cooling plate 36 also cools the side surface of the energy storage element 1 that it contacts.

If the internal spaces are not connected, when the energy storage element 1 generates heat, the water in the heat transfer section 31 that contacts the energy storage element 1 absorbs the heat of vaporization from the energy storage element 1 and evaporates, rapidly cooling the energy storage element 1. The generated water vapor is cooled by the cooling plate 36 and condenses into water. The water absorbs heat from the energy storage element 1 and vaporizes, and the energy storage element 1 is cooled.

In this embodiment, the cooling section 35 has a simple structure, which prevents the heat from being transferred to the adjacent storage element 1 from being transferred to the heated storage element 1, and also prevents the heat from being transferred to the adjacent storage elements 1 in a chain reaction.

In addition, in the above-mentioned energy storage device, each of the energy storage elements 1 is formed in a rectangular parallelepiped shape, the cooling unit 35 is provided with a cooling plate 36 that cools the multiple energy storage elements 1 by contacting a surface other than the long side on which the heat transfer unit 31 of each of the energy storage elements 1 abuts, and the cooling unit 35 is configured to allow heat to be conducted between the cooling plate 36 and the heat transfer unit 31.

With the above configuration, heat is conducted between the cooling plate 36 and the heat transfer section 31, so heat is dissipated well. The gas generated by the evaporation of the liquid is cooled and liquefied, and the liquid absorbs heat from the energy storage element 1 again, allowing it to cool the energy storage element 1.

In the above-mentioned power storage device, the cooling plate 36 and the heat transfer section 31 are integrated so that the liquid or the gas produced by vaporizing the liquid can circulate.

According to the above configuration, the liquid in one heat transfer section 31 in contact with the heated energy storage element 1 evaporates, and the gas generated flows through the cooling plate 36 by thermal convection and flows to the other heat transfer section 31. The gas is liquefied in the other heat transfer section 31 and flows to the one heat transfer section 31, and the liquid circulates.
Therefore, the liquid is reused for cooling the energy storage elements 1, and the energy storage elements 1 are cooled efficiently.
Furthermore, the temperature difference between one long side surface and the other long side surface of one energy storage element 1 is reduced, and the temperature difference between the energy storage elements 1 is reduced. Then, the circulation of gas and liquid reduces the temperature difference between the multiple energy storage elements 1, enabling efficient cooling. Even when a low level of heat generation occurs that is not abnormal, the heat transfer section 31 effectively dissipates the heat from the energy storage elements 1, and the temperature difference between the energy storage elements 1 is reduced.

Third Embodiment
8 is a perspective view of a cooling unit 37 according to the third embodiment. In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals and detailed description thereof will be omitted.
The cooling unit 37 of the third embodiment has a configuration in which the bottom surfaces 31b of the four heat transfer units 31 of the cooling unit 30 of the first embodiment are in contact with a cooling plate 38. As in the first embodiment, the heat transfer units 31 contain liquid, such as water.
There is no internal communication between the heat transfer portion 31 and the cooling plate 38. The cooling plate 38 may be configured to be cooled by a cooling device (not shown).

When the central energy storage element 1 generates heat, as in the first embodiment, the water in the heat transfer section 31 that contacts the energy storage element 1 evaporates, and the heat of vaporization that occurs during evaporation cools the energy storage element 1. The resulting water vapor flows through the other heat transfer sections 31, and water produced by condensation flows to the heat transfer section 31 with the least amount of water. The cooling plate 38 cools the bottom surface of the energy storage element 1 and also cools the heat transfer section 31. The water in the heat transfer section 31 that contacts the energy storage element 1 absorbs heat from the energy storage element 1 and evaporates, cooling the energy storage element 1.

In this embodiment, as in the first and second embodiments, the cooling section 37 has a simple structure to suppress the transfer of heat to the adjacent storage element 1 from the heated storage element 1, and also to suppress the chain transfer of heat to the adjacent storage elements 1.

Fourth Embodiment
9 is a perspective view of a cooling unit 39 according to a fourth embodiment. In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals and detailed description thereof will be omitted.
In this embodiment, an internal pressure release valve 34 is provided in the center of the upper surface of each heat transfer portion 31 .

10 is an explanatory diagram for explaining cooling when the burst valve 20 of the central storage element 1 is opened. When the internal pressure of the storage element 1 reaches or exceeds a predetermined value, the burst valve 20 opens and the volatilized components of the electrolyte are released to the outside.
The internal pressure release valves 34 of the adjacent heat transfer sections 31 are opened by the heat of the energy storage elements 1. Fig. 10 shows a case where the internal pressure release valves 34 of the two adjacent heat transfer sections 31 are opened.
Steam is ejected from the internal pressure release valve 34, and the heat of vaporization at this time cools the energy storage element 1.
Since the heat transfer sections 31 are connected by the connecting sections 32 and 33, the liquid in the heat transfer sections 31 whose internal pressure release valves 34 are not opened is constantly supplied, and the energy storage elements 1 are continuously cooled.
If the amount of liquid is sufficient to cool one energy storage element 1 in total, the reduction in energy density can be minimized and the chain reaction of overheating can be efficiently suppressed.

The present invention is not limited to the contents of the above-described embodiment, and various modifications are possible within the scope of the claims. In other words, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.
In the first to third embodiments, the energy storage element 1 is a lithium ion secondary battery, but the energy storage element 1 is not limited to a lithium ion secondary battery. The energy storage element 1 may be another secondary battery containing an organic solvent, a primary battery, or an electrochemical cell such as a capacitor.
The power storage device according to the present invention can be particularly suitably used as a power source for vehicles. The power storage device according to the present invention can also be suitably used for industrial purposes such as power storage systems (large-scale power storage systems, small-scale home power storage systems), distributed power supply systems combined with natural energy such as solar power and wind power, power supply systems for railways, and power supply systems for automated guided vehicles (AGVs).

REFERENCE SIGNS LIST 1 Energy storage element 2 Cover plate 3 Case body 4 Positive electrode terminal 8 Negative electrode terminal 6, 10 Gasket 11 Case 20 Rupture valve 30, 35, 37, 39 Cooling section 31 Heat transfer section 32, 33 Connection section 34 Internal pressure release valve 36, 38 Cooling plate 40 Case 100 Energy storage device

Claims (5)

A plurality of storage elements;
a cooling unit that cools the power storage element,
The cooling section contains a liquid, is arranged at least between the energy storage elements, and has a heat transfer section in contact with the energy storage elements to cool the energy storage elements by the heat of vaporization of the liquid. The power storage device according to claim 1, characterized in that it has a connecting portion that connects a plurality of the heat transfer portions so that the internal spaces are connected. Each of the storage elements is formed in a rectangular parallelepiped shape,
the cooling unit includes a cooling plate that is in contact with a surface of each of the energy storage elements that is different from a long side surface that is in contact with the heat transfer unit and that cools the plurality of energy storage elements;
3 . The power storage device according to claim 1 , wherein the cooling portion is configured to allow heat to be conducted between the cooling plate and the heat transfer portion. 4 . The power storage device according to claim 3, characterized in that the cooling plate and the heat transfer section are integrated to allow the liquid or the gas produced by vaporizing the liquid to circulate. The electric storage device according to any one of claims 1 to 4, characterized in that the cooling section has an internal pressure release valve that releases the internal pressure when the internal pressure of the cooling section exceeds a predetermined pressure.

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