JP2007299660A - Electrical power storage device and its temperature control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric power storage device that can be refrigerated effectively when charge and discharge are repeated within a short time, and its temperature control method. <P>SOLUTION: An electric power storage cell 1 is constituted of one electrode part 10 and two temperature control parts 11 extended respectively in right and left directions from the electrode part 10. In the temperature control part 11, housing containers 2, 3 which are respectively pasted to the surface and the rear face of the electrode part 10 and which function as the housing containers are further extended in right and left directions from the electric power storage cell, and pasted together. The extended parts of the housing containers 2, 3 constitute a corrugated part 4 as a heat radiation member by being bent into a shape in which recesses and protrusions may be repeated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power storage device and a temperature control method thereof, and more particularly, to a stacked power storage device in which a plurality of electric double layer capacitors, lithium secondary batteries, capacitors, lithium ion capacitors, and the like are stacked and a temperature control method thereof.

  Electric storage devices such as electric double layer capacitors (also called electric double layer capacitors), aluminum electrolytic capacitors, lithium-ion batteries, and lithium-ion capacitors generate large amounts of heat when large amounts of rapid charge and discharge are repeated. The temperature rises. It is known that the lifetime is halved every 7-10 ° C. for any power storage device when the temperature rises.

  Until now, large power storage devices were not used for applications that repeatedly charge and discharge in a short time, so the problem did not surface. However, in recent years, the promotion of the spread of new energy and the promotion of energy saving Recognizing the necessity and “wrinkle” of the power generated by solar cells and wind power, that is, the amount of power generation that changes greatly in a short time is absorbed by the power storage device to minimize the impact on the system The problem has surfaced as it is used as a buffer power source for improving the fuel efficiency of hybrid vehicles, and as a buffer power source that absorbs frequent load fluctuations such as motors and saves energy by energy regeneration.

  Medium- and large-sized power storage devices use stacked power storage devices in which power storage cells are electrically connected in series in order to increase the DC voltage and decrease the current value to reduce orthogonal transformation and power loss. It is also called a module or a battery pack.

  Patent Document 1 discloses a configuration in which electric double layer capacitor cells are stacked via a flat plate heat conductor in order to cope with internal heat generation. FIG. 3 of Patent Document 1 shows a thin metal plate. The method of cooling by utilizing the heat conduction to the side surface is shown.

  Patent Document 2 discloses a configuration in which a heat transfer frame is provided on the three outer sides of a metal laminate container as a storage container for an electric double layer capacitor cell, and the heat is released to the outside by contacting the side surface of the laminate. FIG. 5 of Patent Document 2 shows a cross-sectional view in which the peripheral portion of the metal laminate container is sandwiched between heat transfer frames and brought into contact with the side surface of the laminate. In addition, as a storage container, a metal container and a plastic container are also used.

JP 2003-133188 A (FIG. 7) Japanese Patent Laying-Open No. 2003-272974 (FIG. 5)

  In the power storage device disclosed in Patent Document 1, although the position where heat is generated is near the center of the cell, it is not cooled unless it travels through the side surface of the laminate. There is also a drawback in that it cannot be cooled effectively due to the thermal resistance at the contact portion between the plate and the side surface of the laminate.

  In addition, in the power storage device disclosed in Patent Document 2, although the position where heat is generated is near the center of the cell, heat is transferred from the peripheral part of the metal laminate container to the heat transfer frame, and further from the heat transfer frame to the laminate. It takes time to conduct heat, because there is heat resistance at the contact part between the metal laminate container and the heat transfer frame, and the heat transfer frame and the side of the laminate. As with Patent Document 1, there is a drawback that cooling cannot be effectively performed.

  That is, the conventional power storage devices disclosed in Patent Documents 1 and 2 are configured to cool the heat generated in the power storage cell after being transferred to the side surface of the laminate, so that the cooling is performed. It took time, and the thermal resistance was high, so that it could not be cooled effectively. In particular, when charging / discharging is repeated in a short time, the cooling is not in time, and the stacked power storage device may become high temperature and deteriorate.

  In addition, even if the performance of some power storage cells deteriorates and the amount of heat generated by charging / discharging increases, only the same level of cooling as other cells can be performed, resulting in faster deterioration, resulting in a stacked power storage device. There was a problem that the entire lifetime was shortened.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a power storage device that can be effectively cooled when charging and discharging are repeated in a short time and a method for adjusting the temperature thereof. And

  The power storage device according to the present invention is a power storage device in which a plurality of power storage cells in which at least one pair of a positive electrode member and a negative electrode member opposed via a separator are stored in a storage container are stacked in a first direction. The positive electrode terminal connected to the positive electrode member and the negative electrode terminal connected to the negative electrode member extend in a second direction perpendicular to the first direction, and the storage container has a first direction and a second direction, respectively. The heat dissipation member is configured by extending in a third direction perpendicular to the heat dissipation member, and the heat dissipation member is in thermal contact with each other in the adjacent power storage cells.

  In the power storage device according to the present invention, the storage container forms a heat radiating member by being extended, and the heat radiating members are in thermal contact with each other between adjacent power storage cells. Therefore, even when charging and discharging are repeated in a short time, the cooling can be effectively performed.

<Embodiment 1>
FIG. 1 is a top view showing a structure of a power storage cell 1 constituting the stacked power storage device according to the first embodiment. FIG. 2 is a front view of the power storage cell 1. FIG. 3 is a top view of a power storage device configured by stacking five power storage cells 1. In this specification, the direction in which the power storage cells 1 are stacked (the vertical direction in FIG. 3) is referred to as a first direction.

  As shown in FIGS. 1 and 2, the power storage cell 1 includes one electrode unit 10 and two temperature control units 11 extending in the left-right direction of the electrode unit 10. Although not shown in the drawings, a plurality of positive electrode members and negative electrode members that are opposed to each other with a separator interposed therebetween are built in the electrode unit 10.

  As shown in FIGS. 1 and 2, the temperature adjustment unit 11 includes storage containers 2 and 3 (for example, metal laminate containers) that are attached to the front and back surfaces of the electrode unit 10 and function as storage containers. Further extending in the left-right direction from each other and pasting together. The extended portions of the storage containers 2 and 3 constitute a corrugated portion 4 as a heat radiating member by being bent into a shape that repeats unevenness.

  In the upper part of the power storage cell 1, a positive electrode terminal 5 and a negative electrode terminal 6 that are connected to and extend to the positive electrode member and the negative electrode member in the power storage cell 1, respectively, and a discharge valve 7 are provided. In the present specification, a direction in which the positive electrode terminal 5 and the negative electrode terminal 6 extend (a direction from the depth toward the front in FIG. 3) is referred to as a second direction. Moreover, the direction (left-right direction in FIG. 3) in which the storage containers 2 and 3 extend is referred to as a third direction. These first to third directions are assumed to be perpendicular to each other.

  The storage containers 2 and 3 are generally laminated with an ultrathin polyethylene film on the front and back of an aluminum foil having a thickness of several tens of microns. In this embodiment, the aluminum foil has a thickness of 0.1 mm or more and By using a relatively thick material having a thickness of less than 1 mm, the total thickness of the aluminum foil when the corrugated portion 4 was formed by stacking two sheets was set to 0.2 mm or more and less than 2 mm. Thereby, the mechanical strength required for the corrugated part 4 could be secured.

  As the storage containers 2 and 3, in order to increase the thermal conductivity of the power storage cell 1 in the third direction and increase the cooling capacity, it is conceivable to use a thicker one of 1 mm or more. However, since the storage containers 2 and 3 become bulky when they become too thick, when the power storage cells 1 are stacked as shown in FIG. 3, the volume of the power storage device becomes large. Therefore, in order to ensure compactness while ensuring mechanical strength, about 0.1 to 1 mm is desirable.

  The storage containers 2 and 3 are not limited to aluminum foil but may be copper foil or the like. By using copper having higher thermal conductivity than aluminum, the cooling capacity can be further increased. In addition, a corrosion-resistant metal container made of stainless steel, a plastic container formed by mixing carbon, ceramics, or the like can also be used.

  In FIG. 3, five power storage cells 1 are connected in series by connecting the positive electrode terminal 5 and the negative electrode terminal 6 between the adjacent power storage cells 1. Moreover, between the power storage cells 1 adjacent to each other, the corrugated portions 4 are brought into thermal contact with each other by bonding.

  As described above, in the power storage device according to the present embodiment, the storage container 2, 3 is further extended in the third direction in the power storage cell 1 to form the corrugated portion 4, thereby functioning as a heat radiating member and increasing the cooling capacity. ing. Therefore, even when charging and discharging are repeated in a short time, the cooling can be effectively performed.

  Moreover, between the power storage cells 1 adjacent to each other, the heat transfer is enhanced by bonding the corrugated portions 4 together. Therefore, even if the performance of some of the power storage cells 1 decreases and the amount of heat generated by charging / discharging increases, the temperature can be kept uniform by dissipating heat from the corrugated portions 4 of the other power storage cells 1. it can. Therefore, deterioration of the power storage device can be prevented and the life can be extended (for example, when five power storage cells 1 are connected as shown in FIG. 3, the cooling capacity can be increased by bonding the corrugated portions 4 together. Is nearly tripled).

<Embodiment 2>
In Embodiment 1, the case where five power storage cells 1 are directly connected to each other has been described with reference to FIG. However, the present invention is not limited to this, or five power storage cells 1 may be brought into thermal contact with each other through a heat conductive plate.

  FIG. 4 is a top view of the power storage device according to the second embodiment. FIG. 4 shows a structure in which a heat conducting plate 12 is interposed between adjacent power storage cells 1 in FIG. That is, the heat conductive plates 12 are interposed between the electrode portions 10 adjacent to each other and between the temperature adjustment portions 11 adjacent to each other. The heat conducting plate 12 is made of aluminum, copper, stainless steel, nickel, or a carbon material such as expanded graphite, glassy carbon, carbon resin molding material, carbon paper, carbon cloth, carbon felt, etc. It contains the same or higher material.

  Thus, in the power storage device according to the present embodiment, the heat conducting plate 12 is interposed between the power storage cells 1 adjacent to each other. Accordingly, heat can be radiated using the heat conductive plate 12 in addition to the corrugated portion 4. Therefore, in addition to the effect of Embodiment 1, the effect that it can cool more effectively is produced.

<Embodiment 3>
In Embodiment 1-2, the corrugated part 4 is comprised by bending the extended part of the storage containers 2 and 3 extended from the power storage cell 1 in the shape which repeats an unevenness | corrugation using FIGS. Explained when to do. However, the present invention is not limited thereto, or the extended portions of the storage containers 2 and 3 may remain straight without being bent.

  FIG. 5 is a top view showing the structure of the power storage cell 1a constituting the power storage device according to the third embodiment. FIG. 6 is a front view of the power storage cell 1a. FIGS. 5 to 6 are the extended portions of the storage containers 2 and 3 in FIGS. 1 and 2, and instead of forming the corrugated portion 4 by bending it into a shape that repeats unevenness, the straight portion 4 a is configured without bending. It is a thing. Although the storage containers 2 and 3 may be thin, it is possible to increase the thermal conductivity in the left-right direction by forming the straight portion 4a thick using a thick container.

  FIG. 7 is a top view of a power storage device configured by stacking five power storage cells 1a. In FIG. 7, in the power storage cells 1a adjacent to each other, a corrugated plate 15 (corrugated portion) is interposed between the straight portions 4a. The corrugated plate 15 is configured to include a metal having high thermal conductivity such as stainless steel, nickel, aluminum, or copper, and is bent into a shape that repeats unevenness.

  Thus, in the power storage device according to the present embodiment, the storage containers 2 and 3 are further extended in the third direction in the power storage cell 1a to form the straight portion 4a, and the corrugated plate 15 is interposed therebetween. Therefore, it functions as a heat radiating member to enhance the cooling capacity. Therefore, the same effects as those of the first embodiment are obtained.

<Embodiment 4>
In Embodiments 1-3, the case where the storage containers 2 and 3 are further extended in the third direction from the power storage cell 1 to function as heat dissipation members has been described with reference to FIGS. However, the present invention is not limited thereto, or the heat radiating member may be provided separately from the storage containers 2 and 3.

  FIG. 8 is a top view showing the structure of the power storage cell 1b constituting the power storage device according to the fourth embodiment. FIG. 8 shows a structure in which a heat conduction plate 12a is provided as a heat radiating member separately from the storage containers 2 and 3, instead of extending the storage containers 2 and 3 to form the corrugated portion 4 in FIG.

  FIG. 9 is a front view of the heat conducting plate 12a.

  FIG. 10 is a top view of a power storage device configured by stacking five power storage cells 1b. In FIG. 10, instead of extending the storage containers 2 and 3 to form the corrugated portion 4 in FIG. 3, a heat conduction plate 12a is provided separately from the storage containers 2 and 3, and interposed between the adjacent power storage cells 1. It is a thing.

  As shown in FIGS. 8 to 10, the heat conducting plate 12 a is composed of one straight portion 16 and two corrugated portions 17 extending in the left-right direction of the straight portion 16.

  Similarly to the corrugated plate 15 of the third embodiment, the heat conductive plate 12a includes a metal having high heat conductivity such as stainless steel, nickel, aluminum, or copper. Further, the corrugated portion 17 is bent into a shape that repeats unevenness.

  Thus, in the power storage device according to the present embodiment, instead of extending the storage containers 2 and 3 to form the heat dissipation member, the heat conductive plate 12a is provided separately from the storage containers 2 and 3, and the power storage devices adjacent to each other are provided. By interposing between the cells 1b, it functions as a heat radiating member to enhance the cooling capacity. Therefore, the same effects as those of the first embodiment are obtained.

<Embodiment 5>
In the fourth embodiment, the cooling capacity may be further increased by arranging the heat storage material in the concave portion of the corrugated portion 17.

  FIG. 11 is a top view of the power storage device according to the fifth embodiment. FIG. 11 shows the heat storage material 18 arranged in the concave portion of the corrugated portion 17 in FIG. 10.

  The heat storage material 18 is preferably a molten salt that melts at 50 to 80 ° C. For example, sodium acetate (melting latent heat: 63 kcal / kg, melting point temperature: 58 ° C.) can be used.

  In addition to this, a polymer latent heat storage material can be used as the livestock heat material 18. For example, in the case of polyethylene glycol (PEG), the temperature range can be freely selected from 50 ° C. to 100 ° C. depending on the molecular weight, and heat can be stored in a wide temperature range by combining polyethylene glycols having different molecular weights. . For example, a combination of PEG2000, PEG4000, and PEG8000 can realize the heat storage material 18 capable of cooling latent heat in steps from 50 ° C to 80 ° C.

  The heat storage material 18 is desirably mixed with activated carbon or carbon black and disposed in the concave portion of the corrugated portion 17 so that it does not flow down even when melted, or a partition is provided in the concave portion of the corrugated portion 17 to physically May be retained. Or the thermal storage material 18 may be arrange | positioned in the recessed part of the corrugated part 17 in the state put into the vinyl bag.

  Moreover, the heat storage material 18 does not need to be arrange | positioned at the recessed part of all the corrugated parts 17, and may be arrange | positioned partially. Further, it is desirable to arrange a material that melts at a relatively low temperature at a location close to the electrode portion 10 and a material that melts at a relatively high temperature at a location far from the electrode portion 10. By arranging in this way, even when the heat generation at the electrode 10 is relatively low temperature and is easily affected by the thermal resistance of the corrugated portion 17, the heat transfer path from the electrode 10 to the heat storage material 18 is shortened to reduce the thermal resistance. The influence can be reduced. Therefore, quicker cooling is possible.

  As described above, in the power storage device according to the present embodiment, the heat storage material 18 is disposed in the concave portion of the corrugated portion 17 in the fourth embodiment. Therefore, in addition to the effects of the fourth embodiment, the cooling capacity is further increased. There is an effect that can be.

  In addition, in the above, although the case where the heat storage material 18 was arrange | positioned to the corrugated part 17 which concerns on Embodiment 4 was demonstrated, it is not restricted to this, The corrugated part 4 which concerns on Embodiment 1-2, or Embodiment 3. You may arrange | position to the corrugated board 15 which concerns on.

<Embodiment 6>
In Embodiment 1-5, the case where the recessed part of the corrugated part 4 was cooled was demonstrated. However, when charging / discharging at a remarkably low temperature such as below zero, the efficiency is lowered, and the temperature of the concave portion of the corrugated portion 4 may be increased.

  FIG. 12 is a top view showing the structure of the power storage cell 1c constituting the power storage device according to the sixth embodiment. FIG. 12 shows a state in which a rod-shaped heater 19 is disposed in the concave portion of the corrugated portion 4 in FIG.

  As described above, the power storage device according to the present embodiment is the one in which the heater 19 is disposed in the concave portion of the corrugated portion 4 in the first embodiment, and at the time of charging / discharging at a low temperature (under zero or the like) First, the heater 19 is energized to heat the corrugated unit 4 and rapidly raise the temperature of the power storage cell 1. Therefore, in addition to the effect of Embodiment 1, there exists an effect that it can charge / discharge efficiently.

  In the above description, the heater 19 is arranged in the corrugated portion 4 according to the first embodiment. However, the present invention is not limited to this, and the corrugated portion 4 according to the second embodiment and the corrugated portion according to the third embodiment. You may arrange | position to the plate 15 or the corrugated part 17 which concerns on Embodiment 4. FIG.

<Embodiment 7>
In the fifth embodiment, the case where the power storage cell 1 is cooled using the heat storage material 18 has been described. However, the power storage cell 1 may be cooled not only using the heat storage material 18 but also using a fan.

  FIG. 13 is a top view showing the structure of the power storage cell 1d constituting the power storage device according to the seventh embodiment. FIG. 13 is for cooling the power storage cell 1 using a fan 20 disposed outside the corrugated unit 4 in place of the heat storage material 18 disposed in the recess of the corrugated unit 4 in FIG. 11.

  In FIG. 13, by energizing and rotating the fan 20, a gas such as air is fed into the concave portion of the corrugated portion 4 and circulated. Thereby, even when charging / discharging is repeated in a short time, the power storage cell 1 can be effectively cooled.

  In addition, the gas flowing through the concave portion of the corrugated unit 4 is not limited to air (atmosphere), and may be, for example, a gas such as nitrogen gas or dry air sealed in a storage container of a stacked power storage device. Good. When these gases are used, it is possible to prevent the corrugated portion 4 from being clogged or corroded by impurities (included in the atmosphere) as compared with the case where the atmosphere is used. In addition, when these gases circulate while being sealed in the storage container of the power storage device, it is possible to rapidly cool these gases by installing a heat exchanger in the circulation path. It is.

  Moreover, since it is desirable that the gas flowing through the concave portion of the corrugated portion 4 is a temperature-adjusted gas, a heating means (a heater or the like) or a cooling means (a heat storage material, a heat exchanger, a cooler) is provided in the gas distribution path Etc.), temperature measuring means (Peltier element etc.) may be provided, and the temperature may be adjusted using these. That is, the temperature of the gas flowing through the concave portion of the corrugated portion 4 is measured by the temperature measuring means, cooled by the cooling means when the temperature is high, and heated by the heating means when the temperature is low. Thereby, quick temperature adjustment becomes possible.

  Thus, in the power storage device according to the present embodiment, in Embodiment 5, the fan 20 is used instead of the heat storage material 18 to cool the concave portion of the corrugated portion 4. Therefore, the same effects as those of the fifth embodiment are obtained.

  Although the first to seventh embodiments have been described without specifying the type of power storage device, the present invention is applicable to any of electric double layer capacitors, lithium secondary batteries, lithium ion capacitors, and the like. it can. In addition to these, the present invention can also be applied to other secondary batteries such as nickel metal hydride batteries.

3 is a top view showing a structure of a power storage cell constituting the power storage device according to Embodiment 1. FIG. It is a front view which shows the structure of the power storage cell which comprises the power storage device which concerns on Embodiment 1. FIG. 2 is a top view showing the structure of the power storage device according to Embodiment 1. FIG. 6 is a top view showing a structure of a power storage device according to Embodiment 2. FIG. FIG. 6 is a top view showing a structure of a power storage cell that constitutes a power storage device according to a third embodiment. It is a front view which shows the structure of the power storage cell which comprises the power storage device which concerns on Embodiment 3. FIG. 6 is a top view showing a structure of a power storage device according to Embodiment 3. FIG. FIG. 6 is a top view showing a structure of a power storage cell that constitutes a power storage device according to a fourth embodiment. It is a front view which shows the structure of the power storage cell which comprises the power storage device which concerns on Embodiment 4. FIG. 6 is a top view showing a structure of a power storage device according to a fourth embodiment. FIG. FIG. 10 is a top view showing a structure of a power storage device according to a fifth embodiment. It is a front view which shows the structure of the power storage cell which comprises the power storage device which concerns on Embodiment 6. FIG. It is a front view which shows the structure of the power storage cell which comprises the power storage device which concerns on Embodiment 7. FIG.

Explanation of symbols

1, 1a to 1d Power storage cell, 2, 3 Storage container, 4, 17 Corrugated part, 4a, 16 Straight part, 5 Positive terminal, 6 Negative terminal, 7 Release valve, 10 Electrode part, 11 Temperature control part, 12, 12a heat conduction plate, 15 corrugated plate, 18 heat storage material, 19 heater, 20 fan.

Claims (9)

A power storage device in which a plurality of power storage cells in which at least one set of a positive electrode member and a negative electrode member facing each other via a separator are stored in a storage container are stacked in a first direction,
A positive electrode terminal connected to the positive electrode member and a negative electrode terminal connected to the negative electrode member extend in a second direction perpendicular to the first direction;
The storage container constitutes a heat dissipation member by extending in a third direction perpendicular to the first direction and the second direction,
The heat dissipation member is a power storage device in which the adjacent power storage cells are in thermal contact with each other. A power storage device in which a plurality of power storage cells in which at least one set of a positive electrode member and a negative electrode member facing each other via a separator are stored in a storage container are stacked in a first direction,
A positive electrode terminal connected to the positive electrode member and a negative electrode terminal connected to the negative electrode member extend in a second direction perpendicular to the first direction;
A heat conducting plate interposed between each of the power storage cells,
The heat conducting plate constitutes a heat dissipation member by extending in a third direction perpendicular to the first direction and the second direction,
The heat dissipation member is a power storage device in which the adjacent power storage cells are in thermal contact with each other. The power storage device according to claim 1 or 2,
The said storage container or the said heat conductive board which comprises the said heat radiating member is an electric power storage device which comprises the corrugated part by being bent in the shape which repeats an unevenness | corrugation. The power storage device of claim 1,
The said storage container which comprises the said heat radiating member is a metal laminate container, Comprising: The electric power storage device whose thickness is 0.1 mm or more. The power storage device of claim 1,
A heat conducting plate interposed between each of the power storage cells,
The heat conducting plate is a power storage device that constitutes a heat dissipation member by extending in the third direction. The power storage device according to any one of claims 1 to 5,
A power storage device in which a heater is provided in the storage container or the heat conducting plate constituting the heat radiating member. The power storage device according to any one of claims 1 to 5,
A power storage device in which a heat storage material is provided in the storage container or the heat conduction plate constituting the heat dissipation member. A method for adjusting the temperature of the power storage device according to claim 3, comprising:
The temperature control method of an electric power storage device provided with the process of flowing gas to the said corrugated part. The temperature control method of the power storage device according to claim 8,
A method for adjusting the temperature of a power storage device, comprising adjusting the temperature of the gas.

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