JP2019160525A - battery - Google Patents

Abstract

To provide an all-solid battery capable of suppressing a sudden temperature rising of a battery without increasing resistance loss of the battery.SOLUTION: An all-solid battery 1000 comprises: a power generation part 100 having at least one element battery; a terminal part 200 having a positive electrode terminal 201 and a negative electrode terminal 202; and at least one first metal foil 301 electrically connecting the power generation part 100 and the positive electrode terminal 201 and at least one second metal foil 302 electrically connecting the power generation part 100 and the negative electrode terminal 202, and further comprises: a collector foil part 300 arranged between the power generation part 100 and the terminal part 200; an endotherm member 303 arranged in the collector foil part 300 while being contacted to the first metal foil 301 and the second metal foil 302; and a battery case 400 housing at least one part of the terminal part 200, the power generation part 100, and the collector foil part 300. The element battery includes a solid electrolyte, and the endotherm member 303 contains one or more kind sugar alcohol.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a battery provided with an endothermic material.

  A battery may suddenly generate heat due to a short circuit or the like. As a technique for preventing battery overheating when the temperature of the battery suddenly rises, Patent Document 1 discloses a laminate having at least one layer in which a positive electrode plate and a negative electrode plate are laminated via a separator, An electrode group formed by laminating a plurality of laminated bodies, a positive battery terminal electrically connected to the positive electrode plate of each laminated body, and an electrically connected to the negative electrode plate of each laminated body A negative electrode battery terminal, a current path between each of the laminates and the positive battery terminal, and a current path between each of the laminates and the negative battery terminal. And a temperature rise prevention element that cuts off the current path by heat transmitted from the laminated body that is in an overheated state, a positive battery terminal, and a negative battery terminal are provided, Electrode group, temperature rise prevention element Nonaqueous secondary battery comprising a battery container housing the beauty nonaqueous electrolyte solution is described.

JP 2013-222594 A JP 2017-084460 A JP, 2006-021280, A JP 2012-169166 A

  According to the technique described in Patent Document 1, when the temperature of the battery suddenly rises, the temperature rise prevention element arranged in the middle of the current path interrupts the current path, so that the battery is overheated. It is said that the progress of the temperature rise can be surely prevented. That is, the temperature rise prevention element functions as a temperature fuse. However, in the technique described in Patent Document 1, it is necessary to insert a thermal fuse in series with the circuit. Therefore, during normal energization, a resistance loss occurs in the thermal fuse, and the input of the battery is caused by the resistance loss. And the output decreases.

  An object of the present invention is to provide an all-solid-state battery capable of suppressing rapid temperature rise of the battery without increasing the resistance loss of the battery.

  In one embodiment of the present invention, a power generation unit including at least one unit cell, a terminal unit including a positive electrode terminal and a negative electrode terminal, and at least one first that electrically connects the power generation unit and the positive electrode terminal. A metal foil, and at least one second metal foil for electrically connecting the power generation unit and the negative electrode terminal, and a foil collecting unit disposed between the power generation unit and the terminal unit, , An endothermic material disposed in contact with the first metal foil and the second metal foil, and at least a part of the terminal portion, the power generation unit, the foil collection unit, and the endothermic material. A solid state battery, wherein the unit cell includes a solid electrolyte, and the endothermic material includes one or more sugar alcohols.

In this specification, the “endothermic material” refers to a substance that absorbs heat generated by an endothermic reaction when abnormal heat generation of the battery occurs due to a short circuit or the like.
It should be noted that the sugar alcohol of the endothermic material exists as a solid having a certain shape at the normal time of the battery (before the battery is abnormally heated due to a short circuit or the like, for example, at room temperature).

  ADVANTAGE OF THE INVENTION According to this invention, the all-solid-state battery which can suppress rapid temperature rising of a battery, without increasing the resistance loss of a battery can be provided.

It is a figure which illustrates typically the all-solid-state battery 1000 which concerns on one Embodiment of this invention. (A) It is a top view of the all-solid-state battery 1000. FIG. (B) It is BB arrow sectional drawing of (A). (C) It is CC sectional view taken on the line of (A). It is a figure which illustrates unit cell 10 typically. FIG. 2A is a plan view of a unit cell 10. FIG. 2B is a bottom view of the unit cell 10. (C) It is a CC arrow side view of (A). It is sectional drawing which illustrates the laminated body 110 typically.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these forms. The drawings do not necessarily reflect accurate dimensions. In the drawing, some symbols may be omitted. Unless otherwise specified in this specification, the notation “A to B” for numerical values A and B means “A or more and B or less”. In this notation, when a unit is attached to only the numerical value B, the unit is also applied to the numerical value A. Further, the terms “or” and “or” mean logical sums unless otherwise specified.

<All-solid battery 1000>
FIG. 1 is a diagram schematically illustrating an all solid state battery 1000 according to an embodiment of the present invention. 1A is a plan view of the all-solid-state battery 1000, FIG. 1B is a cross-sectional view taken along the line BB in FIG. 1A, and FIG. It is CC sectional view taken on the line of C). The all-solid-state battery 1000 includes: a power generation unit 100; a terminal unit 200; a foil collection unit 300 disposed between the power generation unit 100 and the terminal unit 200; a heat absorbing material 303 disposed in the foil collection unit 300; A battery case 400 that houses at least a part of the unit 200, the power generation unit 100, and the foil collecting unit 300. The power generation unit 100 includes unit cells 10, 10,... (Hereinafter, simply referred to as “unit cell 10”). The terminal unit 200 includes a positive terminal 201 and a negative terminal 202. The foil collection unit 300 includes first metal foils 301, 301,... (Hereinafter sometimes simply referred to as “first metal foil 301”) that electrically connect the power generation unit 100 and the positive electrode terminal 201, and , Second metal foils 302, 302,... That electrically connect the power generation unit 100 and the negative electrode terminal (hereinafter simply referred to as “second metal foil 302”). 1B, which is a cross-sectional view taken along the line BB in FIG. 1A, shows a positive electrode terminal 201 and first metal foils 301, 301,. 1A, which is a cross-sectional view taken along the line CC in FIG. 1A, shows the negative electrode terminal 202 and the second metal foils 302, 302,. Furthermore, in the foil collection part 300, the heat absorption material 303 is arrange | positioned in contact with the 1st metal foil 301 and the 2nd metal foil 302 (FIG. 1 (B) and (C)). The endothermic material 303 contains one or more sugar alcohols. The power generation unit 100 includes a stacked body 110 in which the batteries 10, 10,. The unit cell 10 contains a solid electrolyte.

(Unit cell 10)
The unit cell 10 is a battery unit that can be discharged or charged by an electrochemical reaction. The electricity generated in the unit cell 10 is taken out through the current collector and the first and second metal foils. The unit cell 10 includes a solid electrolyte. For example, in the unit cell 10, ions move between the positive electrode and the negative electrode through a solid electrolyte layer containing a sulfide solid electrolyte. The unit cell 10 is an all-solid unit cell and does not contain an electrolytic solution. In the case of an electrolyte battery, there is a possibility that the electrolyte solution and the endothermic material may react. Therefore, in order to prevent contact between the electrolyte solution and the endothermic material, a separate layer or the like is provided between the electrolyte battery and the endothermic material. There is a need. As a result, the volume energy density of the battery as a whole decreases. On the other hand, in the case of an all-solid unit battery, such a need is not necessary, so that the volume energy density of the entire battery can be increased.

  In the following description, a lithium ion all-solid battery will be described as an example of the unit cell 10, but the all-solid battery applicable as the unit cell 10 is not limited to a lithium ion battery. Depending on the application, a sodium ion battery, a copper ion battery, a silver ion battery, and other metal ion batteries may be considered. However, since the energy density is high, a lithium ion all-solid battery is preferable. The unit cell 10 may be a primary battery or a secondary battery. However, abnormal heat generation of the battery is likely to occur when the battery is used for a long time by repeated charging and discharging. That is, it is preferable that the unit cell 10 is a secondary battery rather than a primary battery from the viewpoint that the above effect becomes more remarkable.

  FIG. 2 is a diagram schematically illustrating the unit cell 10. 2A is a plan view of the unit cell 10, FIG. 2B is a bottom view of the unit cell 10, and FIG. 2C is a side view taken along the line CC in FIG. 2A. It is. The unit cell 10 includes a positive electrode 11, a negative electrode 12, and a solid electrolyte layer 13 disposed between the positive electrode 11 and the negative electrode 12. The positive electrode 11 includes a positive electrode mixture layer 11a and a positive electrode current collector 11b, and the negative electrode 12 includes a negative electrode mixture layer 12a and a negative electrode current collector 12b. In FIG. 2, the first metal foil 301 and the second metal foil 302 are shown together with the unit cell 10.

The positive electrode mixture layer 11a and the negative electrode mixture layer 12a include at least an active material, and optionally further include a solid electrolyte, a binder, and a conductive additive. Any active material capable of occluding and releasing ions can be used as the active material. Among the active materials, two materials having different potentials for charging and discharging ions (charge / discharge potential) are selected, a material showing a noble potential is used as a positive electrode active material, and a material showing a base potential is used as a negative electrode active material described later. Can be used respectively. When constituting a lithium battery, for example, as a positive electrode active material, lithium cobaltate, lithium nickelate, Li _{1 + α} Ni _1/3 Mn _1/3 Co- _1/3 O ₂ , lithium manganate, spinel-type lithium composite oxide Lithium-containing composite oxides such as lithium titanate can be used, and carbon materials such as graphite and hard carbon, Si and Si alloys, Li ₄ Ti ₅ O _{12 and the} like can be used as the negative electrode active material. The positive electrode active material may have a coating layer such as lithium niobate on the surface. The solid electrolyte is preferably an inorganic solid electrolyte. This is because the ionic conductivity is higher than that of the organic polymer electrolyte. Moreover, it is because it is excellent in heat resistance compared with an organic polymer electrolyte. Preferred solid electrolytes include oxide solid electrolytes such as Li ₃ PO ₄ , Li ₂ S—P ₂ S ₅ , Li ₂ S—SiS ₂ , LiI—Li ₂ S—SiS ₂ , LiI—Si ₂ S—P _2. it can be exemplified _{S 5, LiI-Li 2 S} -P 2 O 5, LiI-Li 3 PO 4 -P 2 S 5 sulfide solid electrolyte such. Among these, a sulfide solid electrolyte containing Li ₂ S—P ₂ S ₅ is particularly preferable. Any known binder can be used as the binder. Examples thereof include butadiene rubber (BR), styrene butadiene rubber (SBR), acrylate butadiene rubber (ABR), and polyvinylidene fluoride (PVdF). As the conductive assistant, carbon materials such as acetylene black and ketjen black, and metal materials such as nickel, aluminum, and stainless steel can be used. The content of each component in the positive electrode active material layer 11a and the negative electrode active material layer 12a, and the shape and thickness of the positive electrode active material layer 11a and the negative electrode active material layer 12a can be the same as those in the past. In addition, the positive electrode active material layer 11a and the negative electrode active material layer 12a obtained the slurry-like electrode composition by putting the active material, the solid electrolyte arbitrarily contained, a binder, and a conductive support agent in a solvent and kneading. Thereafter, the electrode composition can be prepared by applying the electrode composition to the surface of the current collector and drying it.

  The positive electrode current collector 11b and the negative electrode current collector 12b may be formed of a metal foil, a metal mesh, or the like. Metal foil is particularly preferable. By using a metal foil as the current collector, the positive electrode current collector 11b and the first metal foil 301 can be integrally formed of the same material, and the negative electrode current collector 12b and the second metal foil 302 can be formed. Can be integrally formed of the same material, so that the manufacturing process can be simplified. Examples of the metal that can constitute the positive electrode current collector 11b include stainless steel, Ni, Cr, Au, Pt, Al, Fe, Ti, and Zn. Examples of the metal that can constitute the negative electrode current collector 12b include stainless steel, Cu, Ni, Fe, Ti, Co, and Zn.

The solid electrolyte layer 13 includes a solid electrolyte having conductivity of ions occluded and released by the positive electrode active material contained in the positive electrode mixture layer 11a and the negative electrode active material contained in the negative electrode mixture layer 12a. As such a solid electrolyte, the solid electrolyte described above in relation to the positive electrode mixture layer 11a and the negative electrode mixture layer 12a can be used without particular limitation. However, the solid electrolyte layer 13 preferably contains a sulfide solid electrolyte. Examples of preferred solid electrolytes include oxide solid electrolytes such as Li ₃ PO ₄ , Li ₂ S—P ₂ S ₅ , Li ₂ S—SiS ₂ , LiI—Li ₂ S—SiS ₂ , LiI—Si ₂ S—. can be mentioned _{P 2 S 5, LiI-Li} 2 S-P 2 O 5, LiI-Li 3 PO 4 -P 2 S 5 sulfide solid electrolyte such. Among these, a sulfide solid electrolyte containing Li ₂ S—P ₂ S ₅ is particularly preferable. The solid electrolyte layer 13 may contain two or more kinds of solid electrolytes. The solid electrolyte layer 13 optionally contains a binder. As the binder, the same binder as that used for the positive electrode and the negative electrode can be used. The content of each component in the solid electrolyte layer 13 and the shape and thickness of the solid electrolyte layer 13 can be the same as those in the past. The solid electrolyte layer 13 is obtained by applying a slurry electrolyte composition by kneading a solid electrolyte and an arbitrarily contained binder in a solvent, and then applying the electrolyte composition to the surface of the substrate. It can be produced through a process such as drying.

(Metal foil 301, 302)
In FIG. 2, the first metal foil 301 and the second metal foil 302 are shown together with the unit cell 10. The first metal foil 301 is electrically connected to the positive electrode current collector 11b, and the second metal foil 302 is electrically connected to the negative electrode current collector 12b. Examples of metals that can constitute the first metal foil 301 include the metals described above as the metals that can constitute the positive electrode current collector 11b, in addition to known high-conductivity metals such as Ag, Cu, and Au. Can do. Examples of metals that can constitute the second metal foil 302 include the metals described above as the metals that can constitute the negative electrode current collector 12b, in addition to known high-conductivity metals such as Ag, Cu, and Au. be able to. In the unit cell 10, the first metal foil 301 is integrally formed of the same material as the positive electrode current collector 11b, and the second metal foil 302 is integrally formed of the same material as the negative electrode current collector 12b. ing. According to such a form, it becomes possible to simplify the manufacturing process of the all-solid-state battery 1000.

(Laminated body 110)
The unit cell 10 is configured by laminating and integrating the above layers (the positive electrode current collector 11b, the positive electrode mixture layer 11a, the solid electrolyte layer 13, the negative electrode mixture layer 12a, and the negative electrode current collector 12b). The The number of the unit cells 10 provided in the all-solid-state battery 1000 is not particularly limited, and may be an arbitrary number of 1 or more. In particular, it is preferable that a plurality of unit cells 10 are stacked to form a stacked body (laminated battery). The all solid state battery 1000 includes a laminated body (laminated battery) 110. FIG. 3 is a cross-sectional view schematically illustrating the stacked body 110. The stacked body 110 is formed by integrally stacking a plurality of unit cells 10, 10,... By sharing a current collector (positive electrode current collector 11b or negative electrode current collector 12b). In the laminated body 110, the positive electrode current collector 11b shared by the set of unit cells 10 and 10 adjacent to each other is provided with a positive electrode mixture layer 11a on both surfaces thereof. Further, the negative electrode current collector 12b shared by the set of adjacent unit cells 10 and 10 is provided with a negative electrode mixture layer 12a on both surfaces thereof. The positive electrode current collectors 11b, 11b,... Are electrically connected to the first metal foils 301, 301,..., Respectively, and the negative electrode current collectors 12b, 12b,. , ... are electrically connected. As shown in FIG. 1B, each of the first metal foils 301, 301,... Electrically connected to each of the positive electrode current collectors 11b, 11b,. The part 200 is electrically connected to the positive terminal 201. Further, as shown in FIG. 1C, the second metal foils 302, 302,... Electrically connected to the negative electrode current collectors 12b, 12b,. The terminal portion 200 is electrically connected to the negative terminal 202. In this way, the unit cells 10 are electrically connected in parallel.

(Positive electrode terminal 201, negative electrode terminal 202)
Reference is again made to FIGS. 1B and 1C. The all-solid-state battery 1000 has a terminal portion 200 that includes a positive electrode terminal 201 and a negative electrode terminal 202. The first metal foil 301 drawn out from each positive electrode current collector 11b of the multilayer body 110 is electrically connected to the positive electrode terminal 201, and the second metal foil 301 drawn out from each negative electrode current collector 12b of the multilayer body 110. The metal foil 302 is electrically connected to the negative electrode terminal 202. Various metal materials can be used for the positive electrode terminal 201 and the negative electrode terminal 202 without limitation as usual. Further, as a method of electrically connecting the first metal foil 301 to the positive electrode terminal 201 and a method of electrically connecting the second metal foil 302 to the negative electrode terminal 202, spot welding, laser welding, resistance welding, A known connection method such as electromagnetic pressure welding, seam welding, brazing or the like can be used without particular limitation.

(Endothermic material 303)
Reference is again made to FIGS. 1B and 1C. The all-solid-state battery 1000 includes an endothermic material 303 disposed in the foil collection unit 300 in contact with the first metal foil 301 and the second metal foil 302. The endothermic material 303 includes one or more sugar alcohols as an endothermic material, and may include a binder in addition to the endothermic material. In the all-solid-state battery 1000, an endothermic material 303 is disposed in contact with the first metal foil 301 and the second metal foil 302 in the foil collection unit 300, and between each unit cell 10 and the positive electrode terminal 201. In the conductive path and the conductive path between each unit cell 10 and the negative electrode terminal 202, an element (for example, a thermal fuse, a thermistor, or the like) that provides higher electrical resistance than the first metal foil 301 and the second metal foil 302 is provided. Since it is not inserted in series with the circuit, the all-solid-state battery 1000 can suppress a rapid temperature rise of the battery without increasing the resistance loss of the battery. In all solid state battery 1000, heat absorbing material 303 is arranged in contact with first metal foil 301 and second metal foil 302 in foil collecting section 300, and therefore each heat absorbing material 303 and each unit cell that is a heat generation location. Since the distance to 10 is short, the thermal resistance between each unit cell 10 that is a heat generation point and the heat absorbing material 303 is reduced. Therefore, according to the all-solid-state battery 1000, since the heat-absorbing material 303 can efficiently absorb the heat generated from the battery, it is possible to more effectively suppress the temperature rise of the battery. Note that the endothermic material 303 preferably contains no inorganic hydrate.

  The endothermic material 303 contains one or more sugar alcohols. These sugar alcohols exist as a solid during normal battery operation, and absorb heat by melting when the battery is abnormally heated.

  According to the knowledge of the present inventors, sugar alcohol is (I) a material that absorbs heat by melting, (II) can be plastically deformed and easily layered, and (III) water at the battery operating temperature. Will not be released.

  Examples of sugar alcohols include mannitol, xylitol, erythritol, lactitol, maltitol, sorbitol, galactitol and the like. The endothermic material 303 particularly preferably contains mannitol as a sugar alcohol. Mannitol has a large endotherm compared to other sugar alcohols. Further, mannitol is easily re-solidified by cooling even after it has melted and functions as an endothermic layer. That is, it is considered that mannitol can be used repeatedly as an endothermic material.

  As described above, the sugar alcohol exists as a solid during normal battery operation, and absorbs heat by melting when the battery generates abnormal heat. Sugar alcohol (the mixture when endothermic material 303 contains a mixture of two or more sugar alcohols) is either (a) a melting point of 70 ° C. or higher and 250 ° C. or lower, or (b) 70 ° C. or higher and 250 ° C. or lower. In the DSC curve obtained by the endothermic onset temperature and the endothermic peak temperature or (c) suggested scanning calorimetry (in an argon atmosphere, the heating rate is 10 ° C./min) It is preferred that it be completed. By using a sugar alcohol having such characteristics, heat generated from the battery can be absorbed in a more appropriate temperature range.

  The content of sugar alcohol in the endothermic material 303 (the total content when the endothermic material 303 includes two or more sugar alcohols) is not particularly limited, but is preferably 80% by mass or more. Preferably it is 95 mass% or more. The upper limit is not particularly limited. For example, the endothermic material 303 may include only a sugar alcohol in addition to the optionally contained binder.

  The endothermic material 303 preferably does not contain an inorganic hydrate. The inorganic hydrate releases a small amount of water (hydration water) even at the battery operating temperature (60 ° C.). When the unit cell 10 includes a sulfide solid electrolyte, the sulfide solid electrolyte may deteriorate due to the reaction between the hydrated water released from the inorganic hydrate and the sulfide solid electrolyte.

  The endothermic material 303 may contain a binder in addition to the sugar alcohol. The binder binds the sugar alcohols in the solid state more firmly. As the binder, those that do not cause a chemical reaction with the sugar alcohol can be used without particular limitation, and various binders such as butadiene rubber (BR) and polyvinylidene fluoride (PVdF) can be used. The binder content in the endothermic material 303 (the total content when two or more binders are included) is not particularly limited, but is preferably 20% by mass or less, more preferably 5% by mass or less. is there. The lower limit is not particularly limited, and may be 0% by mass. Sugar alcohol can be plastically deformed as described above, and can be formed into a certain shape by pressurization or the like. In addition, since the sugar alcohol can be dissolved in an organic solvent, for example, after applying a solution of the sugar alcohol to the first metal foil 301 and the second metal foil 302, the solvent is evaporated, so that the sugar alcohol is first dissolved. It is possible to reduce the thermal resistance between the first metal foil 301 and the second metal foil 302 and the heat absorbing material 303 by closely contacting the metal foil 301 and the second metal foil 302. Thus, the endothermic material 303 can be configured without blending a binder.

  The endothermic material 303 may contain components other than the sugar alcohol and the binder as long as the performance of the endothermic material 303 is not impaired. For example, an inorganic material that does not release moisture even when heated may be included. However, it is preferable that the endothermic material 303 does not contain an inorganic material. For example, an inorganic hydroxide may cause a chemical reaction with the sugar alcohol described above. Even if the heat-absorbing material 303 does not contain an inorganic material, the sugar-absorbing material 303 exhibits sufficient heat-absorbing performance only with the sugar alcohol, so that the heat-absorbing material 303 contains only the sugar alcohol except for the binder that is optionally contained. Is preferred.

  The shape of the heat absorbing material 303 can be determined as appropriate according to the shape of the foil collecting portion 300, but the heat absorbing material 303 is in contact with the first metal foil 301 and the second metal foil 302 in the foil collecting portion 300. It is necessary and it is preferable to coat the surfaces of the first metal foil and the second metal foil 302. Even if the surface of the first metal foil 301 and the second metal foil 302 is covered with the endothermic material 303, even if a gap remains in the foil collecting part 300, the endothermic material 303 may be further filled in the gap. Good.

  The density of the endothermic material 303 is preferably 80% or more, more preferably 85% or more. When the density of the endothermic material 303 is equal to or more than the above lower limit, the endothermic amount per unit volume of the endothermic material 303 can be increased, and the first metal foil 301 and the second metal foil 302 can be removed from the battery. Therefore, it is possible to quickly propagate the heat guided through the heat absorbing material 303, so that it is possible to quickly absorb the heat against the abnormal heat generation of the battery. The “dense density” of the endothermic layer is calculated as follows. First, the weight and volume of the endothermic material 303 are measured, and the density (bulk density) is calculated. The density can be calculated by dividing the calculated density (bulk density) by the true density.

  The method for forming and arranging the heat absorbing material 303 is not particularly limited. For example, the endothermic material 303 can be molded and arranged by molding and arranging a mixture of the sugar alcohol and the optional binder in various shapes. Molding may be dry or wet. For example, in the case of dry molding, the heat absorbing material 303 having various shapes can be produced by mixing the above-described components and then press-molding while arbitrarily heating. Further, for example, the sugar alcohol and the optional binder may be melted and then molded. Further, for example, in the case of wet molding, each of the above components is added to a solvent to prepare a solution or slurry, and the solution or slurry is applied to the surface of the first metal foil 301 or the second metal foil 302. In particular, after the press working, the endothermic material 303 covering the surface of the first metal foil 301 or the second metal foil 302 may be obtained by evaporating and removing the solvent. Further, for example, the sheet-like endothermic material 303 may be obtained by applying the above solution or slurry on a substrate, drying it, and optionally performing press processing. As the solvent, for example, heptane, ethanol, N-methylpyrrolidone, butyl acetate, butyl butyrate and the like can be preferably used. Moreover, you may combine said processing method. For example, the surface of the first metal foil 301 integrally formed with the positive electrode current collector 11b and the surface of the second metal foil 302 formed integrally with the negative electrode current collector 12b are previously formed by wet forming. Then, the laminated body 110 is assembled, the first metal foil 301 and the positive electrode terminal 201 are electrically connected, and the second metal foil 302 and the negative electrode terminal 202 are electrically connected, The space remaining in the foil part 300 may be filled with sugar alcohol (or a mixture of sugar alcohol and a binder) by dry molding.

(Battery case 400)
As long as the battery case 400 can accommodate at least a part of the terminal part 200, the power generation part 100, and the foil collecting part 300, the material and shape thereof are not particularly limited. For example, a metal casing, a laminated film having a laminated metal foil and a resin film, or the like can be used as the battery case 400.

  In the above description of the present invention, the first metal foil 301 is integrally formed of the same material as the positive electrode current collector 11b, and the second metal foil 302 is integrally formed of the same material as the negative electrode current collector 12b. However, the present invention is not limited to this form. As long as the first metal foil and the positive electrode current collector are electrically connected, the form of the connection is not particularly limited. For example, the first metal foil and the positive electrode current collector which are separate members are used. It is also possible to make an all-solid battery in a form in which and are electrically connected by known means such as welding or brazing. Similarly, as long as the second metal foil and the negative electrode current collector are electrically connected, the form of the connection is not particularly limited. For example, the second metal foil and the negative electrode which are separate members are used. It is also possible to make an all-solid battery in a form in which the current collector is electrically connected by a known means such as welding or brazing.

  In the above description of the present invention, the all solid state battery 1000 having the stacked body 110 formed by stacking the six unit cells 10 is taken as an example, but the present invention is not limited to this mode. The number of the unit cells 10 included in the stacked body 110 can be an arbitrary number of 2 or more. However, from the viewpoint of facilitating the provision of a laminated battery with less warpage, the number of unit cells 10 to be laminated and integrated is an even number (2, 4, 6,...). Is preferred.

  In the above description related to the present invention, the set of all adjacent unit cells 10 and 10 includes the stacked body 110 integrated by sharing the current collector (the positive electrode current collector 11b or the negative electrode current collector 12b). Although the form of the all-solid-state battery 1000 is given as an example, the present invention is not limited to this form. For example, between a set of one unit cell in which a predetermined number of unit cells 10, 10,... Are integrally stacked and a set of the other unit cell in which a predetermined number of unit cells 10, 10,. Thus, an all-solid-state battery including a stacked body in which the current collector is not shared is also possible.

  In the above description of the present invention, the all solid state battery 1000 in which all the unit cells 10, 10,... Are electrically connected in parallel has been taken as an example, but the present invention is not limited to this form. For example, an all solid state battery having a plurality of unit cells electrically connected in series may be used.

  Hereinafter, the present invention will be described in more detail based on examples and comparative examples. However, the following examples are examples of the present invention, and the present invention is not limited to the following examples.

<Example 1>
1. ~ 6. The lithium ion all-solid battery of the present invention was produced by the procedure described above.
(1. Preparation of positive electrode mixture layer)
100 parts by weight of a ternary active material (particle size 1 to 10 μm) as a positive electrode active material, 33.3 parts by weight of a sulfide solid electrolyte as a solid electrolyte, and 1.5 parts by weight of PVdF as a binder, A positive electrode mixture paste was prepared by mixing in heptane so that the solid content was 50% by weight and dispersing the solid content in heptane using an ultrasonic homogenizer (UH-50 manufactured by SMT). The obtained positive electrode mixture paste is applied to the surface of the positive electrode current collector (aluminum foil) integrally formed of the same material as that of the first metal foil and then dried, so that the surface of the positive electrode current collector is dried. A positive electrode mixture layer was prepared.

(2. Production of negative electrode mixture layer)
100 parts by weight of natural graphite as a negative electrode active material, 72.4 parts by weight of a sulfide solid electrolyte as a solid electrolyte, 1.1 parts by weight of PVdF as a binder, and a solid content of 50% by weight A negative electrode mixture paste was prepared by mixing in heptane and dispersing the solid content in heptane using an ultrasonic homogenizer (UH-50 manufactured by SMT). The obtained negative electrode mixture paste is applied to the surface of the negative electrode current collector (copper foil) integrally formed of the same material as the second metal foil, and then dried, so that the surface of the negative electrode current collector is removed. A negative electrode mixture layer was prepared.

(3. Production of solid electrolyte layer)
95 parts by weight of a sulfide solid electrolyte as a solid electrolyte and 5 parts by weight of PVdF as a binder are mixed in heptane so that the solid content is 50% by weight, and an ultrasonic homogenizer (UH-50 manufactured by SMT) is mixed. The solid content was dispersed in heptane using a slurry to prepare a slurry solid electrolyte composition. The obtained solid electrolyte composition was applied to the surface of the negative electrode layer or the positive electrode layer and then dried to prepare a solid electrolyte layer on the surface of the negative electrode layer or the positive electrode layer.

(4. Endothermic material arrangement (1))
Mannitol is dissolved in a solvent (heptane), applied to the surfaces of the first metal foil and the second metal foil, and then dried to absorb the heat of the surfaces of the first metal foil and the second metal foil. Covered with material (mannitol).

(5. Assembly and wiring of laminate)
A positive electrode current collector (prepared in 1 above) having a positive electrode mixture layer provided on the surface so that the total number of pairs in which the positive electrode and the negative electrode face each other across the solid electrolyte layer is 20, and the negative electrode mixture layer on the surface After laminating a negative electrode current collector (produced in 2 above) provided with a solid electrolyte layer (produced in 3 above), each of the first metal foils was connected to a positive electrode terminal, and the second metal By connecting each of the foils to the negative electrode terminal, a battery assembly (laminated battery) having a capacity of 2 Ah including the laminate, the first and second metal foils, and the positive electrode terminal and the negative electrode terminal was produced.

(6. Endothermic material arrangement (2))
After embossing the aluminum laminate so that the battery assembly (prepared in 5. above) fits, and placing mannitol as an endothermic material in the embossed recess (site to be the foil collecting part), the battery assembly is housed in the aluminum laminate. The aluminum laminate was sealed.

<Comparative Example 1>
Procedure 4 above. And the above procedure 6. A lithium ion all-solid battery outside the scope of the present invention was produced in the same manner as in Example 1 except that mannitol was not disposed in the embossed recess.

<Evaluation: External short circuit test>
Each of the created batteries was adjusted to 100% charge state (SoC). The positive electrode terminal and the negative electrode terminal of the battery were externally short-circuited for 10 minutes via an external resistance of 5 mΩ, and the temperature change of the battery surface during that time was recorded using a thermocouple thermometer.

<Evaluation results>
In the all solid state battery of Example 1, the temperature increase on the battery surface during the external short circuit was reduced by 20% compared to the all solid state battery of Comparative Example 1. From this result, according to the all-solid-state battery of this invention, it was shown that the rapid temperature rise of a battery can be suppressed.

DESCRIPTION OF SYMBOLS 10 Unit cell 11 Positive electrode 11a Positive electrode mixture layer 11b Positive electrode collector 12 Negative electrode 12a Negative electrode mixture layer 12b Negative electrode collector 13 Solid electrolyte layer 100 Power generation part 110 Stack (laminated battery)
200 terminal portion 201 positive electrode terminal 202 negative electrode terminal 300 foil collecting portion 301 first metal foil 302 second metal foil 303 endothermic material 400 battery case 1000 all solid state battery

Claims (1)

A power generation unit comprising at least one unit cell;
A terminal portion comprising a positive terminal and a negative terminal;
At least one first metal foil that electrically connects the power generation unit and the positive electrode terminal; and at least one second metal foil that electrically connects the power generation unit and the negative electrode terminal; A foil collecting part disposed between the power generation part and the terminal part;
An endothermic material disposed in the foil collecting portion in contact with the first metal foil and the second metal foil;
A battery case that houses at least a part of the terminal part, the power generation part, and the foil collecting part;
The unit cell includes a solid electrolyte;
The all-solid battery, wherein the endothermic material contains one or more sugar alcohols.