JP5395765B2 - Batteries provided with coolant, and assembled batteries provided with coolant - Google Patents

Description

  The present invention relates to a battery including a coolant and an assembled battery including the coolant.

  For example, secondary batteries such as lithium ion secondary batteries, lead storage batteries, nickel metal hydride secondary batteries, various batteries such as fuel cells, power sources such as railways, ships, automobiles, industrial power storage facilities, smart grids, etc. Widely used for power system applications. The various batteries described above may be used as a single battery composed of a single battery, but may be used as an assembled battery in which a plurality of single batteries are connected in order to obtain high output and large capacity electric energy.

  In secondary batteries (hereinafter simply referred to as “batteries” where appropriate), it is known that batteries normally generate heat during charging and discharging. Therefore, in an assembled battery connecting a plurality of batteries, for example, packaging is applied to the assembled battery from the viewpoint of ease of operation and safety, and there is a problem that heat is easily accumulated and heat radiation is very difficult to perform. . Furthermore, there is a case where the battery is housed in a box so as not to get wet from the viewpoint of waterproofing measures, and there is a problem that heat radiation is more difficult to be performed.

  Moreover, when improving battery performance, it is inevitable that the calorific value of a battery increases. However, in the various batteries, it is particularly important to keep the battery temperature in a temperature range as narrow as possible regardless of the increase in the amount of heat generated in order to achieve desired performance. The reason is that the battery performance may be significantly deteriorated when a high temperature state deviating from the normal use temperature range of the battery continues. Therefore, particularly in a high-performance battery, it is extremely preferable to provide a cooling mechanism from the viewpoint of increasing the density and capacity of the battery.

  Examples of such a cooling mechanism include a combination of a coolant and a radiator, use of a high-power cooling fan, and the like. For example, Patent Document 1 describes a technique for attaching a heat pipe to a battery. For example, Patent Document 2 describes a technique for operating a battery in a desired temperature range by bringing a material having a large heat balance in phase change into thermal contact. For example, Patent Document 3 describes a technique that uses latent heat at the time of phase change.

JP 2006-210245 A Special Table 2003-533844 JP 2009-140786 A

  However, the technique described in Patent Document 1 often requires equipment and a power source for driving the cooling mechanism, and there is a problem that it is difficult to reduce the size and weight of the assembled battery. In the techniques described in Patent Documents 2 and 3, it is difficult to cool the battery below the phase change point (for example, the melting point) of the phase change material that causes the phase change. There is also a problem that cooling of the battery is still insufficient.

  The present invention has been made to solve the above problems, and an object of the present invention is to cool the battery more appropriately than in the past.

  As a result of intensive studies to solve the above problems, the present inventors can solve the above problems by bringing a specific one side of the two layers into contact with the battery using a coolant comprising at least two layers. The present invention was completed.

  According to the present invention, the battery can be cooled more appropriately than in the past.

It is the figure which showed typically the cross section of the coolant based on 1st embodiment of this invention about a coolant. It is the figure which showed typically the cross section of the coolant based on 2nd embodiment of this invention about a coolant. It is the figure which showed typically the cross section of the coolant based on 3rd embodiment of this invention about a coolant. It is the figure which showed typically the upper side surface of the coolant based on 4th embodiment of this invention about a coolant. It is the figure which showed typically the principal part structure of the assembled battery set provided with multiple laminated batteries based on 1st embodiment of this invention about the assembled battery provided with a coolant. It is the figure which showed typically the principal part structure of the battery set provided with the cylindrical battery based on 1st embodiment of this invention about the battery provided with a coolant. (A) is the figure which showed typically the principal part structure of the assembled battery set provided with two or more cylindrical batteries based on 2nd embodiment of this invention about the assembled battery provided with a coolant, (b) is ( The upper side view of the assembled battery set shown to a), (c) is the upper side view of the modification in which the coolant 1 is arrange | positioned in the transversal direction of the battery storage case 11 in the assembled battery set shown to (a). . It is a graph which shows the temperature change with respect to elapsed time in the case where the coolant manufactured in Example 1 is used, and the case where the coolant manufactured in Comparative Example 1 is used. It is a graph which shows the temperature change with respect to elapsed time in the case where the coolant manufactured in Example 2 is used, and the case where the coolant manufactured in Comparative Example 2 is used.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment” as appropriate) will be described in detail, but the present embodiment is not limited to the following contents and does not depart from the gist thereof. Any change can be made within the range.

[1. Batteries provided with coolant, and assembled batteries provided with coolant]
A battery including a coolant (hereinafter referred to as “battery set according to the present embodiment” as appropriate) according to the present embodiment is a battery including a coolant that includes at least a battery and a coolant. However, it has at least a water retaining layer containing at least one moisture absorbing / releasing material that absorbs and releases water according to temperature, and an endothermic layer containing an endothermic material that absorbs heat when dissolved in water. And the water retention layer side of a coolant and the battery are contacting.
Hereinafter, the present embodiment will be described focusing on the battery set according to the present embodiment. However, the battery set according to the present embodiment includes a plurality of batteries included in the battery set according to the present embodiment, and the components and configurations of the following coolant included in the battery set according to the present embodiment. The same applies to the coolant provided in the battery pack set according to the present embodiment. Therefore, the description about the coolant provided in the assembled battery set according to the present embodiment is omitted.

[1-1. Coolant]
The coolant included in the battery set according to the present embodiment (hereinafter referred to as “the coolant according to the present embodiment” as appropriate) cools the battery in contact with the battery, and water is supplied depending on the temperature. It has at least a water retention layer containing a moisture absorption / release material that absorbs or releases (that is, absorbs / releases) and an endothermic layer containing an endothermic material that absorbs heat when dissolved in water.

[Water retention layer]
The water retention layer absorbs heat when water is released or releases heat when water is absorbed by the moisture absorption / release material contained therein. That is, for example, when a battery in contact with a coolant generates heat, the water retention layer absorbs heat generated by releasing water to suppress excessive and rapid temperature rise of the battery. When the battery is excessively cooled, the water retention layer absorbs water and releases heat, thereby suppressing an excessive temperature drop of the battery.

  The temperature at which the moisture absorbing / releasing material absorbs and releases water is arbitrary as long as the effect of the present invention is not significantly impaired. If the temperature is higher than this temperature, the moisture absorbing / releasing material releases water, while the temperature is below this temperature. Absorbs water. As such a temperature, the temperature of the moisture absorbing / releasing material is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, particularly preferably 40 ° C. or higher, and the upper limit is preferably 110 ° C. or lower, more preferably It is desirable to release water at 90 ° C. or less, particularly preferably 65 ° C. or less. If the temperature at which water is released is in the above range, the water retention layer changes phase while releasing water when the temperature of the battery rises, so the heat released from the battery is absorbed and the battery temperature rises excessively and rapidly. Can be suppressed. When the temperature at which water is released is lower than the above range, for example, when the environmental temperature is high, such as in summer, the water retention layer may release water regardless of the temperature of the battery, and the battery may not be properly cooled. . Also, if the temperature at which water is released is higher than the above range, the water retention layer may not release water properly even if the battery temperature rises excessively, and the battery may not be cooled properly. There is sex.

  The temperature at which the moisture absorption / release material absorbs / releases water can be measured, for example, by the following method. That is, when the moisture absorption / release material was measured using a differential scanning calorimeter (DSC-6200 type, manufactured by Seiko Instruments Inc.) and the conditions were a sample amount of 20 mg ± 1 mg and a heating rate of 2 ° C./min, The intersection point between the extension line of the base line from the low temperature side of the heat capacity curve and the tangent line at the low temperature side peak maximum slope point of the heat capacity curve can be set as the above temperature.

  The moisture absorbing / releasing material is usually a gel formed by mixing water and a gelling agent. Such a gelling agent is arbitrary as long as the effect of the present invention is not significantly impaired, and may be determined in consideration of the water absorption / release temperature (for example, melting point, phase change point, etc.). It can be used suitably. Specific examples of the polysaccharide include, for example, agar, agarose, carrageenan, gellan gum, and the like are preferable among the polysaccharides. That is, in the coolant according to the present embodiment, it is preferable that the moisture absorption / release material absorbs / releases water at 30 ° C. or more and 110 ° C. or less and contains water and polysaccharides. In addition, a polysaccharide may be used individually by 1 type and may use 2 or more types by arbitrary ratios and combinations.

  Further, the amount of the moisture absorbing / releasing material contained in the water retaining layer is arbitrary as long as the effects of the present invention are not significantly impaired. However, the concentration of the gelling agent contained in the water retention layer is preferably 1.5% by weight or more, more preferably 2% by weight or more, and the upper limit is preferably 20% by weight with respect to the entire water retention layer. It is desirable that the moisture absorption / release material is contained so as to be not more than%, more preferably not more than 10% by weight. If the amount of the gelling agent is too small, the gelling agent may not be able to absorb water. If it is too much, it may be difficult to release water that can suppress the temperature rise of the battery that has generated heat. There is sex.

  The moisture absorbing / releasing material preferably releases water at 15 ° C. or higher and 30 ° C. or lower and contains water and collagen and / or gelatin. When the moisture absorbing / releasing material absorbs and releases water at 15 ° C. or more and 30 ° C. or less, for example, when the environmental temperature is near 0 ° C., for example, in the winter season, latent heat is generated when the water retaining layer changes phase from liquid to solid. , And excessive and rapid decrease in battery temperature can be suppressed.

  One type of moisture absorbing / releasing material may be included alone in the water retention layer, or two or more types may be included in any ratio and combination. For example, a water retention layer is formed by combining a moisture absorption / release material that releases water at 15 ° C. to 30 ° C. and a moisture absorption / release material that releases water at 30 ° C. to 110 ° C. into the water retention layer. The temperature at which gas is absorbed and released can be set as desired.

  In addition to the moisture absorption / release material, the water retention layer may contain any material as long as the effects of the present invention are not significantly impaired. Such optional materials include, for example, finely divided silica (fumed silica), precipitated silica (hydrous silicic acid), finely divided alumina, finely powdered hollow ceramics and other inorganic fine particles, and high water retention such as sodium polyacrylate. Examples include molecular compounds and preservatives such as benzoic acid. As for these arbitrary components, 1 type may be contained independently and 2 or more types may be contained by arbitrary ratios and combinations.

  When inorganic fine particles are contained in the water retention layer, the content thereof is arbitrary as long as the effects of the present invention are not significantly impaired, but usually 1% by weight or more with respect to the amount of the moisture absorbing / releasing material contained in the water retention layer. The upper limit is usually 20% by weight or less, preferably 10% by weight or less. When there is too much content of inorganic fine particles, there is a possibility that it will be difficult to release water from the water retaining layer to the heat absorbing layer. Further, the number average particle diameter of the inorganic fine particles is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 5 nm or more, preferably 8 nm or more, and the upper limit is usually 50 nm or less, preferably 40 nm or less.

  Moreover, when the water retention layer contains a water retention polymer compound, the content thereof is arbitrary as long as the effect of the present invention is not significantly impaired, but with respect to the amount of the moisture absorbing / releasing material contained in the water retention layer, Usually 1% by weight or more, and the upper limit is usually 20% by weight or less, preferably 10% by weight or less. When there is too much content of a water retention high molecular compound, discharge | release of the water from a water retention layer to a heat absorption layer may become difficult to be performed.

[Endothermic layer]
The coolant according to the present embodiment includes an endothermic layer containing an endothermic material that absorbs heat by dissolving in water released from the water retaining layer, in addition to the water retaining layer. Therefore, the coolant according to the present embodiment has at least such a water retaining layer and an endothermic layer, thereby cooling using the heat of dissolution in addition to cooling using the latent heat (that is, conventional cooling using phase change). The battery whose temperature has risen can be reliably cooled.

  The endothermic material contained in the endothermic layer is arbitrary as long as it absorbs heat when dissolved in water, as long as the effect of the present invention is not significantly impaired. For example, ammonium salts such as ammonium chloride, ammonium nitrate, ammonium sulfate, carbonic acid Examples include sodium salt hydrates such as sodium, sodium sulfate decahydrate, sodium carbonate decahydrate, sodium hydrogensulfate heptahydrate, and sugar alcohols such as monosaccharide alcohols such as urea, xylitol, erythritol, and sorbitol. . Among these, as the endothermic material used in the coolant according to the present embodiment, these endothermic materials are preferable. In addition, an endothermic material may be used individually by 1 type, and may use 2 or more types by arbitrary ratios and combinations.

  The amount of the endothermic material in the endothermic layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 10% by weight or more, more preferably 20% by weight or more, and the upper limit thereof is preferably 90% by weight or less. More preferably, it is 70% by weight or less. When the amount of the endothermic material is too small, there is a possibility that the battery cooling effect due to the endotherm is insufficient.

  Further, the endothermic layer can contain any component in addition to the above endothermic material as long as the effects of the present invention are not significantly impaired. Specific examples of optional components include ammonium dihydrogen phosphate and phosphate esters. The content of an optional component in the endothermic layer is arbitrary as long as the effects of the present invention are not significantly impaired, but is usually 0.1% by weight or more, preferably 0.2% by weight or more, more preferably, with respect to the endothermic layer. Is 0.5% by weight or more, and the upper limit is usually 5% by weight or less, preferably 3% by weight or less, more preferably 2% by weight or less. When there is too much content of arbitrary components, formation of an endothermic layer may become difficult.

[Quantitative relationship between water retaining layer and endothermic layer]
In the battery set according to the present embodiment, when the temperature of the battery rises, water is released from the water retaining layer of the coolant, and the heat absorbing material dissolves in the water to absorb the heat, thereby cooling the battery. ing. Therefore, as long as such effects are not significantly impaired, the amount of the water-retaining layer and the amount of the heat-absorbing layer are arbitrary, but the volume of the heat-absorbing layer is preferably 20% or more, more preferably, the volume of the water-retaining layer. 25% or more, and the upper limit is preferably 100% or less, more preferably 75% or less. When the volume of the endothermic layer is too small, sufficient endotherm cannot be performed, and there is a possibility that high cooling efficiency cannot be achieved as compared with the conventional cooling method using only the phase change. In addition, if the volume of the endothermic layer is too large, the amount of the endothermic material contained in the endothermic layer is excessive with respect to the water released from the water retaining layer, so that the coolant becomes excessive weight and volume, making it compact and lightweight. It may not be possible to provide a complete battery set.

[Other layers]
The coolant according to the present embodiment can have one or more arbitrary layers in addition to the water retention layer and the heat absorption layer as long as the effects of the present invention are not significantly impaired. As such an arbitrary layer, for example, a partition layer can be provided between the water retention layer and the heat absorption layer. By providing the partition layer, there is an advantage that the heat-absorbing material, which is usually a powder, can be easily handled during production.

  The physical properties such as the material and thickness of the partition layer are arbitrary as long as the effects of the present invention are not significantly impaired, but supply of the water released from the water retaining layer to the endothermic layer is not hindered. For example, as a material of the partition layer, for example, a nonwoven fabric, paper, or the like can be used. Further, the thickness is preferably 0.1 mm or more, and the upper limit is preferably 1.5 mm or less.

[Thickness of all layers]
The total thickness of all the layers including the water-retaining layer, the heat-absorbing layer, and a partition layer provided as necessary is arbitrary as long as the effects of the present invention are not significantly impaired. However, this thickness is preferably 1 mm or more, and its upper limit is preferably 30 mm or less. When the thickness is in the above range, a sufficient cooling effect can be obtained, and a small and lightweight battery set can be provided.

[Cooling material exterior]
What stored arbitrary layers (henceforth these layers are collectively called "component layer" suitably), such as the above-mentioned water retention layer and heat absorption layer, and a partition layer provided as needed, in a covering material It is preferable to use it as a coolant. For example, when a bag is used as the covering material, the thickness and material of the bag are arbitrary as long as the effects of the present invention are not significantly impaired, but heat exchange between the battery and the coolant is not hindered. Examples of the material constituting such a covering material include a laminate sheet obtained by bonding nylon and polyethylene, a sheet made of an ethylene vinyl acetate copolymer, a sheet made of an ethylene methyl methacrylate copolymer, and the like.

  In addition, the two layers made of the above materials are used to arrange the constituent layer on one sheet, and then the other layer covers the constituent layer from the top to overlap the two sheets. May be sealed. Alternatively, a single sheet may be used to wrap the component layer with the single sheet and then be folded to seal the overlapping portion of the single sheet.

[1-2. Cooling method]
In the battery set according to the present embodiment, the battery is cooled by contacting the water retention layer side of the coolant and the battery. Here, “contact” in the present embodiment means that the contact surfaces are in close contact with each other as long as heat from the battery can be sufficiently absorbed and the battery can be cooled in heat exchange performed between the water retention layer and the battery. It means "contact" in the broadest sense, whether or not That is, for example, when the battery is a stacked battery or a square battery, the contact surface is usually rectangular, but the size of the rectangle is not particularly limited as long as the effect of the present invention is not significantly impaired. The degree of contact does not necessarily need to be in close contact, and the contact pressure at the time of contact is arbitrary as long as the effect of the present invention is not significantly impaired.

When the battery is a cylindrical battery, the contact surface when the water retaining layer side of the coolant contacts the battery is usually curved. The contact area and contact pressure at this time are also arbitrary as long as the effects of the present invention are not significantly impaired.
Further, the contact between the water retention layer and the battery is usually made through an outer cover material in which at least the water retention layer and the heat absorption layer are accommodated.

[1-3. Cooling mechanism in battery set according to this embodiment]
The conventional coolant is not divided into two layers, and the battery is cooled using only the phase change. However, in the battery set according to the present embodiment, the coolant is divided into at least two layers of a normal gel water retention layer and a normal powder heat absorption layer, and the coolant water retention layer side and the battery are further divided. The battery is cooled by contact.

  That is, in the coolant according to the present embodiment, when the battery temperature rises and heat is released from the battery, the water retention layer receives the released heat and suppresses excessive and rapid temperature rise of the battery. doing. In addition, the water retention layer that has received the released heat maintains the thermal energy balance of the water retention layer by releasing the water it has. The water released from the water retaining layer dissolves the endothermic material of the endothermic layer. Since this dissolution is an endothermic reaction, it takes away the heat of the battery. Thus, in this embodiment, in addition to the suppression of the excessive and rapid temperature rise of the battery by the water retaining layer, the battery also has an efficient battery cooling effect over a wide range of temperatures by the endothermic layer. Moreover, since the structure of the coolant used in this embodiment is simple, there is an advantage that a small and light battery set can be provided according to this embodiment.

  What temperature the battery retains when the water retaining layer releases water and the endothermic layer cools the battery [1-1. It can be arbitrarily set as described in “Moisture absorption / release material” of “Coolant”. Therefore, it is possible to manufacture an appropriate coolant according to the type of battery, and it is possible to cool the battery more automatically and more reliably than before. Further, even when the temperature of the battery further rises after the battery is once cooled by the heat absorbing layer, the water retaining layer absorbs the heat released from the battery by further releasing water, so that the battery Excessive and rapid temperature rise can be suppressed.

  Further, when the temperature of the battery is lowered after the endothermic component contained in the endothermic layer is dissolved, the endothermic component is deposited, and the water retaining layer absorbs water and releases latent heat. Therefore, the released latent heat is used for suppressing the temperature drop of the battery, and thus, excessive and rapid temperature drop of the battery can be suppressed. In the battery set according to the present embodiment, the endothermic material contained in the endothermic layer is precipitated (or recrystallized) when the environmental temperature is lowered or the water retaining layer absorbs water. Even when the temperature of the battery rises again due to the endothermic material thus deposited, the battery can be automatically and reversibly cooled. This reversible process is also performed in a state where the endothermic layer and the water retaining layer are mixed (that is, when the endothermic layer and the water retaining layer are not separated into two distinct layers). In addition, even when only the water retention layer is precipitated (or recrystallized), the coolant can absorb the heat released from the battery by the function of the water retention layer, and the excessive and rapid temperature rise of the battery can be suppressed. . Therefore, it is possible to provide a function similar to cooling using latent heat at the time of phase change in a quasi-reversible manner.

  Further, in the battery set according to the present embodiment, the water retention layer side of the coolant and the battery are in contact with each other. The reason why the battery is brought into contact with the water retaining layer side instead of the endothermic layer is that the endothermic material contained in the endothermic layer is usually in powder form. Such a powdery endothermic material has voids, and air is usually present in the voids. The air layer usually has a lower thermal conductivity than liquids and solids, for example, a water retaining layer (usually gel-like and almost free of voids) and endothermic layer (usually powdery) of the same thickness. And having a large number of voids), the water retaining layer is superior in thermal conductivity. Therefore, in the battery set according to the present embodiment, by contacting the battery with the water retention layer side instead of the heat absorbing layer of the coolant, the coolant quickly absorbs the heat released by the battery, and the battery temperature rises. Has the advantage of more sensitive response.

  Regarding the possibility of water leakage from the coolant, when the battery temperature rises, the water retention layer releases water, but the released water is absorbed by the endothermic layer. On the other hand, when the battery temperature is lowered, the water retention layer again absorbs the water released by the water retention layer and contained in the heat absorption layer. Thus, the water exchanged between the water retention layer and the endothermic layer was originally contained in the water retention layer. Therefore, the battery set according to the present embodiment essentially suppresses the possibility of water leakage from the coolant.

[1-4. Coolant structure]
As long as the coolant according to the present embodiment has at least a water retention layer and an endothermic layer and has a structure in which the water retention layer side of the coolant can contact the battery, the structure of other portions is arbitrary.

FIG. 1 is a diagram schematically showing a cross section of a coolant 1A according to the first embodiment of the present invention for the coolant. The coolant 1 </ b> A according to the first embodiment includes a water retention layer 2, an endothermic layer 3, a partition wall layer 4, and a bag 5. The water retention layer 2, the heat absorption layer 3, the partition wall layer 4 and the bag 5 all represent the same as the water retention layer, the heat absorption layer, the partition wall layer and the bag. And the partition layer 4 is provided between the water retention layer 2 and the heat absorption layer 3, and the water retention layer 2 and the heat absorption layer 3 are isolate | separated. Moreover, the partition wall layer 4 and the two sheets are sealed at the left and right ends of the coolant 1 </ b> A to form a bag 5. As the sheet, for example, a laminate sheet having an outer surface made of a nylon polyamide copolymer and an inner surface made of polyvinyl chloride can be used. Sealing may be performed by, for example, heat welding. And a water retention layer 2 side of coolant 1A and a battery can be made to contact by arranging a water retention layer in one side of coolant 1A in this way.
Further, the structure of the coolant is not limited as long as it has a structure in which the water retention layer side of the coolant and the battery can come into contact as described above. For example, the shape of the coolant 1A shown in FIG. By making it into a sheet form, it becomes easy to fit along the container of the cylindrical battery, or to be disposed in the gap between the square batteries or in the gap between the battery storage case used in the battery module and the battery.

  FIG. 2 is a view schematically showing a cross section of the coolant 1B according to the second embodiment of the present invention for the coolant. In the following description, members denoted by the same reference numerals as those in the first embodiment are the same as those in the first embodiment. The coolant 1 </ b> B according to the second embodiment includes a water retention layer 2, an endothermic layer 3, a partition wall layer 4, and a bag 5. In the coolant 1 </ b> B, the heat-absorbing layer 3 is formed so that the water-retaining layer 2 surrounds the partition layer 4. In addition, at the left and right ends of the coolant 1B, two sheets are sealed to form a bag 5. Since the coolant 1B has such a configuration, it can be brought into contact with the battery in any direction in the vertical direction of the coolant 1B (that is, the upward direction and the downward direction in the drawing).

  FIG. 3 is a view schematically showing a cross section of the coolant 1C according to the third embodiment of the present invention for the coolant. The coolant 1 </ b> C according to the third embodiment includes two water retention layers 2, an endothermic layer 3, two partition walls 4, and a bag 5. In the coolant 1 </ b> C, the endothermic layer 3 is sandwiched between the two water retention layers 2 via the partition wall layer 4. Moreover, the two partition walls 4 and the two sheets are heat-sealed at the left and right end portions of the coolant 1C to form a bag 5. Therefore, since the coolant 1C has such a configuration, as in the case of the coolant 1B, the coolant 1C is brought into contact with the battery in any direction of the coolant 1C in the vertical direction (that is, upward and downward on the page). be able to. Further, the coolant 1C shown in FIG. 3 has an advantage that the manufacturing method is easy (a specific manufacturing method will be described later).

  FIG. 4 is a view schematically showing the upper side surface of the coolant 1D according to the fourth embodiment of the present invention for the coolant. The coolant 1D according to the fourth embodiment includes a sealing portion 6 and an enclosure portion 7 having at least a water retention layer and an endothermic layer. The enclosure part 7 has the same structure as the coolants 1A to 1C, for example, and is shown in FIG. 4 as three, but the number of enclosure parts 7 is not limited to three. Moreover, the sealing part 6 delimits the enclosure part 7, and is formed, for example, by heating. Since the coolant 1D has the configuration shown in FIG. 4, the water retention layer and the heat absorption layer in the coolant are not biased, and the heat exchange with the battery is not uneven, so that the battery can be cooled uniformly. . Moreover, since the shape of the sealing part 6 is easy to change as compared with the enclosing part 7, it is easy to bend the coolant 1D at the position of the sealing part 6. Therefore, when the coolant 1D having such a shape is used along the inner wall of a battery storage case in which, for example, a cylindrical battery or a square battery is stored, the battery and the coolant 1D are easily brought into close contact with each other. Further, even if the inner wall of the container is curved, the enclosing portion 7 can be brought into contact with the battery. Furthermore, the coolant 1D described in FIG. 4 has a shape in which a plurality of coolants (that is, the enclosing portion 7 in FIG. 4) are integrally formed as another coolant. Therefore, it is not necessary to arrange another coolant so as to correspond to each of the plurality of batteries, and the coolant can be easily arranged. In addition, it is possible to save time and labor when manufacturing the battery set and the assembled battery set, compared to the case of using a plurality of coolants such as transporting the coolant and inserting it into the assembled battery.

  FIG. 5 is a diagram schematically showing a main configuration of the assembled battery set according to the first embodiment of the present invention for the assembled battery set. In FIG. 5, the coolant 1 </ b> D is used as the coolant 1, and a stacked battery is used as the battery 8. The two coolants 1D are provided between the two batteries 8 so that the water retention layer side of the coolant 1D and the battery 8 are in contact with each other. In other words, the endothermic coolant 1D in FIG. 5 has an endothermic layer disposed on the near side, and the near side coolant in FIG. 5 has a water retention layer disposed on the near side. A grease application part 10 is provided on the contact surface between the coolant 1D and the battery 8. The grease application unit 10 is applied with grease having excellent thermal conductivity, whereby heat exchange between the battery and the coolant can be performed without waste.

  FIG. 6 is a diagram schematically illustrating a main configuration of a battery set including a cylindrical battery according to the first embodiment of the present invention for the battery set. In FIG. 6, the coolant 1D is used as the coolant 1, and a cylindrical battery is used as the battery 8 '. However, the shape of the battery 8 ′ is a cylindrical shape, but may be a prismatic shape. Then, the coolant 1 is wound around the battery 8 ′ having such a shape. At this time, the water retentive layer side of the coolant 1D and the battery 8 'are wound so as to contact each other. Further, as described above, since the sealing portion 6 provided in the coolant 1D can be easily bent, the coolant 1D is provided by being bent at the sealing portion 6 in FIG.

  FIG. 7 is a diagram schematically showing the main configuration of the assembled battery set according to the second embodiment of the present invention for the assembled battery set. In FIG. 7, six batteries 8 ′ are stored in the battery storage case 11, and these batteries 8 ′ are cooled by the coolant 1. However, the number of batteries 8 ′ is not limited to six, and the present embodiment can be similarly applied even when the number of batteries 8 ′ is other than six. For example, when the number of batteries 8 ′ is four in the longitudinal direction of the battery storage case 11 in FIG. 7B, the number of the enclosing parts 7 in the coolant 1D is also four, and the coolant 1 is arranged. It is preferable to adjust the width and size of the sealing portion 6 and the enclosing portion 7 of the coolant 1D so that the position of the battery 8 ′ and the position of the enclosing portion 7 coincide.

  7A and 7B, the coolant 1 is provided between the three batteries 8 ′ arranged in the longitudinal direction of the battery storage case 11 and the inner wall portion of the battery storage case 11. At this time, the direction of the coolant 1 is such that the water retention layer side of the coolant 1 and the secondary battery 8 ′ are in contact with each other. Further, the water storage layer side of the coolant 1 and the secondary battery 8 ′ are in contact with each other between the two sets of secondary battery groups including the three batteries 8 ′ at the center in the vertical direction of the battery storage case 11. As shown, two coolants 1 are provided. In the embodiment shown in FIGS. 7A and 7B, four coolants 1 are provided in the longitudinal direction of the battery storage case 11, and three batteries 8 ′ are in contact with the coolant 1. As shown in FIG. 7C, six coolants 1 may be provided in the short direction of the battery storage case 11 so that the two batteries 8 ′ are in contact with the coolant 1. Thus, when the coolant 1 is arranged in the longitudinal direction of the gap between the batteries, the three batteries 8 ′ can be cooled by the single coolant 1, so that the number of coolants 1 necessary for the configuration can be reduced. On the other hand, when arranged in the short direction, the number of batteries 8 'cooled by one coolant 1 can be reduced, and the battery 8' can be reliably cooled even if the amount of heat generated from one battery 8 'increases. be able to.

[1-5. Manufacturing method of coolant]
The coolant according to the present embodiment can be manufactured by any method as long as the effects of the present invention are not significantly impaired. Hereinafter, although an example of the manufacturing method of the coolant which concerns on this embodiment is demonstrated, the manufacturing method of the coolant which concerns on this embodiment is not limited to the following.

  For example, the water retention layer can be produced by mixing and heating water and the gelling agent, and further mixing and cooling an optional component. At this time, the amounts of water, gelling agent and optional components to be mixed are as described in [1-1. What is necessary is just to adjust each so that it may become the gelatinizer density | concentration demonstrated in the coolant. Moreover, what is necessary is just to set a heating temperature and a cooling temperature suitably according to the kind of gelatinizer.

  And, for example, when the structure of the target coolant is the structure shown in FIG. 1, for example, an endothermic layer made of a premixed endothermic material and other components is disposed on a sheet such as a resin or a laminate sheet, The top is covered with, for example, a nonwoven fabric or paper. Further, a coolant can be manufactured by disposing the water retaining layer prepared by the above method on the top and covering the left and right ends by covering with a sheet.

  Further, when the structure of the coolant is, for example, the structure shown in FIG. 2, for example, a water retention layer is disposed on a laminate sheet or the like, and an endothermic layer wrapped with, for example, a nonwoven fabric is placed thereon, and further the water retention layer and the laminate sheet Are provided in this order, and the end portion is sealed to manufacture the coolant.

  Further, for example, when the structure of the coolant is the structure shown in FIG. A coolant capable of bringing a battery into contact with both sides can be easily manufactured.

  The battery set and the assembled battery set according to the present embodiment can be implemented using the coolant manufactured as described above.

[2. Application range of battery set and assembled battery set according to this embodiment]
The battery set and the assembled battery set according to the present embodiment can be applied to any application as batteries such as a primary battery and a secondary battery. For example, the present invention is particularly applicable to cooling of in-vehicle secondary batteries mounted on automobiles such as assembled battery modules, electric cars such as hybrid cars, and fuel cell cars, where battery heat generation is a major issue. It is.

  Hereinafter, the present embodiment will be described in more detail with reference to examples. However, the present embodiment is not limited to the following examples, and may be arbitrarily modified without departing from the scope of the present invention. Can do.

Example 1
Mix 95.0 g of water and 5.0 g of powdered agar as a gelling agent (manufactured by Ina Food Industry Co., Ltd .; concentration of gelling agent with respect to water is 5% by weight). A liquid was obtained. This suspension was stored in a polyethylene bag (manufactured by Nippon Unipack Co., Ltd.), placed in a cool box kept at a temperature of 5 ° C. or lower, and cooled for a whole day and night to obtain a water retaining layer. The obtained water-retaining layer was once taken out from the bag, the moisture that had oozed out on the surface of the water-retaining layer was wiped off, and again filled in another bag made of polyethylene. The volume of the water retention layer obtained at this time was 20.0 mL. Then, 10.0 mL of ammonium nitrate powder (manufactured by Wako Pure Chemical Industries, Ltd.) (50% by volume with respect to the water-retaining layer) is filled in a polyethylene bag filled with the water-retaining layer, and the bag is kept static until the temperature reaches room temperature (20 ° C.). To produce a coolant.

(Example 2)
95.0 g of water and 5.0 g of powdered gelatin as a gelling agent (manufactured by House Foods Co., Ltd .; 5% by weight of gelling agent concentration with respect to water) are mixed, heated to 80 ° C. with stirring, and suspended. Got. This suspension was stored in a polyethylene bag (manufactured by Nippon Unipack Co., Ltd.), placed in a cool box kept at a temperature of 5 ° C. or lower, and cooled for a whole day and night to obtain a water retaining layer. The obtained water-retaining layer was once taken out from the bag, the moisture that had oozed out on the surface of the water-retaining layer was wiped off, and again filled in another bag made of polyethylene. The volume of the water retention layer obtained at this time was 15.0 mL. Then, 7.5 mL of ammonium nitrate powder (manufactured by Wako Pure Chemical Industries, Ltd.) (50% by volume with respect to the water-retaining layer) is filled in a polyethylene bag filled with the water-retaining layer, and the bag is kept static until the temperature reaches room temperature (20 ° C.). To produce a coolant.

(Comparative Example 1)
30.0 mL of water was packed in a polyethylene bag (manufactured by Nippon Unipack Co., Ltd.) to produce a coolant.

(Comparative Example 2)
95.0 g of water and 5.0 g of powdered gelatin as a gelling agent (manufactured by House Foods Co., Ltd .; 5% by weight of gelling agent concentration with respect to water) are mixed, heated to 80 ° C. with stirring, and suspended. Got. This suspension was stored in a polyethylene bag (manufactured by Nippon Unipack Co., Ltd.), placed in a cool box kept at a temperature of 5 ° C. or lower, and cooled for a whole day and night to obtain a water retaining layer. Remove the water-retaining layer obtained from the bag, wipe off the water that has oozed out on the surface of the water-retaining layer, fill it again into another polyethylene bag, and leave it until the temperature reaches room temperature (20 ° C). Manufactured.

(Evaluation method 1)
Using a hot plate (manufactured by ASONE Co., Ltd.) that simulates a battery as a heating element in order to facilitate temperature control, the cooling effect of the cooling material can be increased depending on whether the cooling material according to this embodiment is used or not. evaluated. First, the coolant manufactured in Example 1 and Comparative Example 1 is placed on each of the two hot plates, and a thermocouple (manufactured by Sukegawa Electric Industry Co., Ltd.) is placed on the surface of the hot plate where the coolant and the hot plate come into contact. Was installed. And the heating target temperature of a hot plate was set to 120 degreeC, the heating was started, and the temperature change with respect to time until the temperature of the contact surface measured with the said thermocouple reached | attained 100 degreeC was measured. The result is shown in FIG.

  As shown in FIG. 8, the time to reach 100 ° C. is 449 seconds when the coolant manufactured in Example 1 is used, and when the coolant manufactured in Comparative Example 1 is used. It was 152 seconds. That is, when the coolant according to the present embodiment is used, it is possible to extend the time required for the heating element to reach a specific temperature, and to prevent reaching a high temperature state in a short time. Therefore, by using the coolant according to the present embodiment, even when the battery temperature rises, the battery can be appropriately cooled, and various batteries such as a single battery and an assembled battery in which a plurality of single batteries are connected. Can be cooled efficiently.

(Comparative evaluation 2)
In order to facilitate temperature control, a hot plate (manufactured by ASONE Co., Ltd.) that simulates a battery as a heating element is used, and when a coolant according to this embodiment is used, a coolant that uses only a conventional phase change is used. The cooling effect of the coolant was evaluated when used. First, the coolant manufactured in Example 2 and Comparative Example 2 is placed on each of the two hot plates, and a thermocouple (manufactured by Sukegawa Electric Industry Co., Ltd.) is placed on the surface of the hot plate where the coolant and the hot plate come into contact. Was installed. And the heating target temperature of a hot plate was set to 80 degreeC, and heating was started, and the temperature change of the contact surface for 120 second from the heating start was measured with the said thermocouple. The result is shown in FIG.

  As shown in FIG. 9, the temperature was 69.3 ° C. when the coolant of Example 2 was used, and 81.1 ° C. when the coolant of Comparative Example 2 was used. Therefore, by using the coolant according to the present embodiment, the temperature rise of the heating element can be suppressed more than in the past, and the battery can be appropriately cooled compared to the conventional cooling method using only the phase change. .

DESCRIPTION OF SYMBOLS 1 Coolant 1A Coolant 1B Coolant 1C Coolant 1D Coolant 2 Water retention layer 3 Endothermic layer 4 Partition layer 5 Bag 6 Sealing part 7 Enclosing part 8 Battery 8 'Battery 9 Coolant 10 Grease application part 11 Battery storage case

Claims (13)

A battery comprising a coolant, comprising at least a battery and a coolant,
A water retaining layer containing at least one moisture absorbing / releasing material that absorbs and releases water according to temperature; and an endothermic layer containing at least one endothermic material that absorbs heat by dissolving in the water. Having at least
A battery comprising a coolant, wherein the water retention layer side of the coolant is in contact with the battery. The moisture absorption / release material releases water at 30 ° C. or higher and 110 ° C. or lower,
The battery comprising the coolant according to claim 1, comprising water and a polysaccharide.   The battery comprising the coolant according to claim 2, wherein the polysaccharide is one or more polymer materials selected from the group consisting of agar, agarose, carrageenan, and gellan gum. The moisture absorption / release material releases water at 15 ° C. or higher and 30 ° C. or lower,
A battery comprising the coolant according to any one of claims 1 to 3, wherein the battery contains water and collagen and / or gelatin.   The endothermic material contains one or more materials selected from the group consisting of sodium salt hydrates, ammonium salts, urea and sugar alcohols, according to any one of claims 1 to 4. A battery comprising the described coolant.   The sodium salt hydrate is one or more compounds selected from the group consisting of sodium carbonate, sodium sulfate decahydrate, sodium carbonate decahydrate and sodium hydrogen sulfate heptahydrate, A battery comprising the coolant according to claim 5.   The battery comprising the coolant according to claim 5 or 6, wherein the ammonium salt is one or more compounds selected from the group consisting of ammonium chloride, ammonium nitrate, and ammonium sulfate. A battery pack comprising at least a plurality of batteries and a coolant, comprising a coolant,
A water retaining layer containing at least one moisture absorbing / releasing material that absorbs and releases water according to temperature; and an endothermic layer containing at least one endothermic material that absorbs heat by dissolving in the water. Having at least
An assembled battery comprising a coolant, wherein the water retention layer side of the coolant is in contact with at least one of the plurality of batteries. The coolant includes a partition layer that separates the water retention layer and the endothermic layer,
The assembled battery comprising the coolant according to claim 8, wherein the water retention layer, the heat absorption layer, and the partition layer are housed in a jacket material.   The coolant according to claim 8, wherein the coolant includes a plurality of sealed portions having the water retaining layer and the heat absorbing layer, and a sealed portion is provided between the adjacent sealed portions. A battery pack comprising:   The assembled battery comprising the coolant according to claim 10, wherein the coolant is bent at the sealing portion.   The assembled battery comprising the coolant according to claim 8 or 9, wherein the coolant has a flat shape.   The coolant according to any one of claims 8 to 12, wherein at least two of the coolants are provided between two adjacent cells of the plurality of cells. Assembled battery.

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