Battery pack

Abstract

To provide a battery pack which can suppress a rise in concentration of hydrogen sulfide gas in the inside.SOLUTION: A battery pack 1 to be mounted on a vehicle comprises: a battery case 10 for internally housing a battery 3 which is formed of an all-solid battery containing a sulfur-based material in a positive electrode and / or a solid electrolyte; and an adsorbent 115 which is disposed on a bottom face frame 11 in the battery case 10 and adsorbs hydrogen sulfide gas. The adsorbent 115 is disposed on an outer periphery 112a of the bottom face frame 11.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a battery pack mounted on a moving body.

Background Art

[0002] A sodium-sulfur battery system is known in which a module filled with dry sand is placed in a heat-insulating container housing a sodium-sulfur battery, and an adsorbent for adsorbing hydrogen sulfide gas or the like is disposed at an opening or the like of the heat-insulating container (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above sodium-sulfur battery system, there is a problem that hydrogen sulfide gas generated from the sodium-sulfur battery cannot be processed until it reaches the adsorbent by concentration diffusion, and the concentration of hydrogen sulfide gas may partially increase inside the heat-insulating container.

[0005] The problem to be solved by the present invention is to provide a battery pack capable of suppressing an increase in the concentration of hydrogen sulfide gas inside.

Means for Solving the Problems

[0006] The present invention solves the above problems by disposing an adsorbent for adsorbing hydrogen sulfide gas on the outer periphery of the bottom of the battery case.

Effects of the Invention

[0007] According to the present invention, by disposing an adsorbent for adsorbing hydrogen sulfide gas on the outer peripheral portion of the bottom of the battery case, it is possible to suppress an increase in the concentration of hydrogen sulfide gas inside the battery case.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a state in which a battery pack in the present embodiment is attached to the floor of an automobile body. FIG. 2 is a plan view showing the battery pack in the present embodiment. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. In the figure, Fr indicates the front side direction of the automobile 2, UPR indicates the upper side direction of the automobile 2, RH indicates the right side direction of the automobile 2, and LH indicates the left side direction of the automobile 2.

[0010] The battery pack of the present embodiment is mounted on a moving body such as an automobile. As shown in FIG. 1, the battery pack 1 of the present embodiment is attached over substantially the entire surface in the range from the front portion of the front floor panel 23 to the rear floor panel 24 of the floor surface 21 of the automobile body 20 of the automobile 2. Note that reference numeral 22 indicates a dash panel and 25 indicates a sill, respectively.

[0011] As shown in FIGS. 2 and 3, the battery pack 1 of the present embodiment includes a battery case 10 that houses a plurality of batteries 3 therein. The battery 3 (also referred to as a battery module) in the present embodiment includes a plurality of battery modules, and each battery module is housed in a module case. Inside the module case, a plurality of thin-film batteries (also referred to as single cells) are housed in a stacked state.

[0012] The single cell of the present embodiment is an all-solid-state battery (all-solid-state lithium-ion secondary battery). That is, the all-solid-state battery includes a positive electrode including a positive electrode active material layer containing a positive electrode active material capable of occluding and releasing lithium ions, a negative electrode including a negative electrode active material layer containing a negative electrode active material capable of occluding and releasing lithium ions, and a solid electrolyte layer interposed between the positive electrode active material layer and the negative electrode active material layer, and has a power generation element. In addition to the power generation element, the all-solid-state battery has an electrode tab and an exterior member that houses the electrode tab and the power generation element. Further, the all-solid-state battery is a battery that uses at least a sulfur-based material, and contains a sulfur component as a material for the positive electrode and / or a material for the solid electrolyte.

[0013] Here, referring to FIGS. 4(a) and 4(b), the structure of the all-solid-state battery 30 that constitutes the battery 3 will be described. FIG. 4(a) is a plan view of the all-solid-state battery 30 according to the present embodiment, and FIG. 4(b) is a cross-sectional view taken along line IV-IV of FIG. 4(a). Note that the structure of the all-solid-state battery 30 is not limited to the structure shown in FIGS. 4(a) and 4(b), and other structures may also be used.

[0014] The all-solid-state battery 30 includes a power generation element 301 having three positive electrode layers 302, seven electrolyte layers 303, and three negative electrode layers 304, a positive electrode tab 305 connected to each of the three positive electrode layers 302, a negative electrode tab 306 connected to each of the three negative electrode layers 304, and an upper exterior member 307 and a lower exterior member 308 that house and seal the power generation element 301, the positive electrode tab 305, and the negative electrode tab 306.

[0015] Note that the number of the positive electrode layer 302, the electrolyte layer 303, and the negative electrode layer 304 is not particularly limited. The power generation element 301 may be composed of one positive electrode layer 302, three electrolyte layers 303, and one negative electrode layer 304. Alternatively, the number of the positive electrode layer 302, the electrolyte layer 303, and the negative electrode layer 304 may be appropriately selected as needed.

[0016] The positive electrode layer 302 constituting the power generation element 301 has a positive electrode current collector 302a extending to the positive electrode tab 305 and positive electrode active material layers formed on both main surfaces of a part of the positive electrode current collector 302a. As the positive electrode current collector 302a constituting the positive electrode layer 302, for example, it can be composed of an electrochemically stable metal foil such as aluminum foil, aluminum alloy foil, copper titanium foil, or stainless steel foil. As the metal used for the positive electrode current collector 302a, nickel, iron, copper, etc. may be used. In addition to these, a clad material of nickel and aluminum, a clad material of copper and aluminum, etc. may be used.

[0017] Instead of metal, a resin having conductivity may be used for the positive electrode current collector 302a. The resin having conductivity can be composed of a resin in which a conductive filler is added to a non-conductive polymer material as needed. As the non-conductive polymer material, for example, materials having excellent potential resistance such as polyethylene (PE; high-density polyethylene (HDPE), low-density polyethylene (LDPE), etc.), polypropylene (PP), polyethylene terephthalate (PET), etc. are used. The conductive filler can be used without particular limitation as long as it is a substance having conductivity. For example, as materials excellent in conductivity, potential resistance, or lithium ion blocking property, metals and conductive carbon can be mentioned. The metal is not particularly limited, but at least one metal selected from the group consisting of Ni, Ti, Al, Cu, Pt, Fe, Cr, Sn, Zn, In, and Sb, or an alloy or metal oxide containing these metals can be mentioned.

[0018] The cathode active material layer constituting the cathode layer 302 is not particularly limited, and examples thereof include layered rock salt type active materials such as LiCoO2, LiMnO2, LiNiO2, LiVO2, Li(Ni-Mn-Co)O2, spinel type active materials such as LiMn2O4, LiNi 0.5 Mn 1.5 O4, olivine type active materials such as LiFePO4, LiMnPO4, and Si-containing active materials such as Li2FeSiO4, Li2MnSiO4. Examples of oxide active materials other than those described above include, for example, Li4Ti5O 12 . Composite oxides containing lithium and nickel are preferably used, and more preferably Li(Ni-Mn-Co)O2 and those in which a part of these transition metals is substituted by other elements (hereinafter, also simply referred to as "NMC composite oxides") are used. As described above, the NMC composite oxide also includes a composite oxide in which a part of the transition metal element is substituted by other metal elements. Examples of other elements in that case include Ti, Zr, Nb, W, P, and the like.

[0019] A sulfur-based cathode active material may be used in the cathode active material layer. Examples of the sulfur-based cathode active material include particles or thin films of organic sulfur compounds or inorganic sulfur compounds, and any material that can release lithium ions during charging and occlude lithium ions during discharging by utilizing the redox reaction of sulfur may be used. Examples of organic sulfur compounds include disulfide compounds and sulfur-modified polyacrylonitrile. Examples of inorganic sulfur compounds include sulfur (S), S-carbon composite, TiS2, TiS3, TiS4, NiS, NiS2, CuS, FeS2, Li2S, MoS2, MoS3, and the like.

[0020] In addition, a cathode active material other than those described above may be used. Examples of the shape of the cathode active material include particulate (spherical, fibrous), thin film, and the like. The content of the cathode active material in the cathode active material layer is not particularly limited. The cathode active material layer may further contain at least one of a solid electrolyte, a conductive assistant, and a binder, if necessary. Examples of the shape of the cathode active material include particulate (spherical, fibrous), thin film, and the like. The content of the cathode active material in the cathode active material layer is not particularly limited. The cathode active material layer may further contain at least one of a solid electrolyte, a conductive assistant, and a binder, if necessary. Examples of the solid electrolyte include sulfide solid electrolytes and oxide solid electrolytes, and those exemplified as the solid electrolytes capable of forming the electrolyte layer 303 described later can be used.

[0021] The conductive assistant is not particularly limited, but preferably has a particulate or fibrous shape. When the conductive assistant is particulate, the shape of the particles is not particularly limited and may be any shape such as powdery, spherical, rod-shaped, needle-shaped, plate-shaped, columnar, irregular, flaky, spindle-shaped, or the like. The average particle diameter (primary particle diameter) when the conductive assistant is particulate is not particularly limited, but is preferably 0.01 to 10 μm from the viewpoint of the electrical characteristics of the battery.

[0022] Examples of the binder include thermoplastic polymers such as polybutylene terephthalate, polyethylene terephthalate, polyvinylidene fluoride (PVDF) (including compounds in which hydrogen atoms are substituted with other halogen elements), polyethylene, polypropylene, polymethylpentene, polybutene, polyether nitrile, polytetrafluoroethylene, polyacrylonitrile, polyimide, polyamide, ethylene-vinyl acetate copolymer, polyvinyl chloride, styrene-butadiene rubber (SBR), ethylene-propylene-diene copolymer, styrene-butadiene-styrene block copolymer and its hydrogenated product, styrene-isoprene-styrene block copolymer and its hydrogenated product; fluororesins such as tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polyvinyl fluoride (PVF); vinylidene fluoride-based fluororubbers such as vinylidene fluoride-hexafluoropropylene-based fluororubber (VDF-HFP-based fluororubber), vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene-based fluororubber (VDF-HFP-TFE-based fluororubber), vinylidene fluoride-pentafluoropropylene-based fluororubber (VDF-PFP-based fluororubber), vinylidene fluoride-pentafluoropropylene-tetrafluoroethylene-based fluororubber (VDF-PFP-TFE-based fluororubber), vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene-based fluororubber (VDF-PFMVE-TFE-based fluororubber), vinylidene fluoride-chlorotrifluoroethylene-based fluororubber (VDF-CTFE-based fluororubber); epoxy resins; and the like. Among them, polyimide, styrene-butadiene rubber, carboxymethyl cellulose, polypropylene, polytetrafluoroethylene, polyacrylonitrile, and polyamide are more preferable.

[0023] And each positive electrode current collector 302a constituting these three positive electrode layers 302 is joined to a positive electrode tab 305. As the positive electrode tab 305, an aluminum foil, an aluminum alloy foil, a copper foil, a nickel foil, or the like can be used.

[0024] The negative electrode layer 304 constituting the power generation element 301 has a negative electrode current collector 304a extending to a negative electrode tab 306 and negative electrode active material layers formed on both main surfaces of a part of the negative electrode current collector 304a. The negative electrode current collector 304a of the negative electrode layer 304 is, for example, an electrochemically stable metal foil such as a nickel foil, a copper foil, a stainless steel foil, or an iron foil.

[0025] The negative electrode layer 304 is formed of a layer containing a negative electrode active material. The type of the negative electrode active material is not particularly limited, and examples thereof include carbon materials, metal oxides, and metal active materials. Examples of the carbon materials include natural graphite, artificial graphite, mesocarbon microbeads (MCMB), highly oriented pyrolytic graphite (HOPG), hard carbon, soft carbon, and the like. Examples of the metal oxides include Nb2O5, Li4Ti5O 12 , SiO, and the like. Further, examples of the metal active materials include simple metals such as In, Al, Si, and Sn, and alloys such as TiSi and La3Ni2Sn7.

[0026] Further, the negative electrode active material may be a metal containing Li. Such a negative electrode active material is not particularly limited as long as it is an active material containing Li. In addition to Li metal, a lithium alloy containing Li may also be used. Examples of the lithium alloy include an alloy of lithium and at least one metal selected from gold (Au), magnesium (Mg), aluminum (Al), calcium (Ca), zinc (Zn), tin (Sn), and bismuth (Bi). Further, the lithium alloy may be an alloy of lithium and two or more of the above-described metals. Specific examples of the lithium alloy include, for example, lithium-gold alloy (Li-Au), lithium-magnesium alloy (Li-Mg), lithium-aluminum alloy (Li-Al), lithium-calcium alloy (Li-Ca), lithium-zinc alloy (Li-Zn), lithium-tin alloy (Li-Sn), lithium-bismuth alloy (Li-Bi), and the like.

[0027] Note that the negative electrode active material layer may contain a lithium alloy, and its configuration is not particularly limited. For example, when the metal other than lithium constituting the lithium alloy is “Me”, it can be in any of the following modes (1) to (3). (1) A single layer composed only of a lithium alloy (that is, a Li-Me layer). (2) A layer composed of a lithium metal layer and a layer composed of a lithium alloy (that is, a Li layer / Li-Me layer). (3) A layer composed of a lithium metal layer, a layer composed of a lithium alloy, and a layer composed of a metal other than lithium (that is, a Li layer / Li-Me layer / Me layer). In the mode (2) above, it is desirable that the layer composed of a lithium alloy (Li-Me layer) be the layer on the electrolyte layer 303 side (the layer forming the interface with the electrolyte layer 303). In the mode (3) above, it is desirable that the layer composed of a metal other than lithium (Me layer) be the layer on the electrolyte layer 303 side (the layer forming the interface with the electrolyte layer 303). When a lithium metal layer containing a lithium metal and a layer containing a metal different from the lithium metal (intermediate layer) are provided, the intermediate layer is a layer between the lithium metal layer and the solid electrolyte, and it is desirable that at least a part of the lithium metal and at least a part of the metal forming the intermediate layer be alloyed.

[0028] For example, when the negative electrode is configured in the mode (3) above, that is, the mode including a layer made of lithium metal, a layer made of a lithium alloy, and a layer made of a metal other than lithium (i.e., Li layer / Li-Me layer / Me layer), by laminating a lithium metal and a metal other than lithium, the interface portion therebetween can be alloyed, and thereby, a layer made of a lithium alloy can be formed at these interfaces. Note that the method of laminating a lithium metal and a metal other than lithium is not particularly limited. For example, a method of depositing a metal other than lithium by vacuum deposition or the like on the layer made of lithium metal to form a layer made of a metal other than lithium on the layer made of lithium metal while alloying these interfaces can be mentioned. Alternatively, a method of depositing a lithium metal by vacuum deposition or the like on the layer made of a metal other than lithium to form a layer made of lithium metal on the layer made of a metal other than lithium while alloying these interfaces can be mentioned.

[0029] In the all-solid-state battery 30 of the present embodiment, the three negative electrode layers 304 are configured such that each negative electrode current collector 304a constituting the negative electrode layer 304 is joined to a single negative electrode tab 306. That is, in the all-solid-state battery 30 of the present embodiment, each negative electrode layer 304 is configured to be joined to a single common negative electrode tab 306.

[0030] The electrolyte layer 303 of the power generation element 301 prevents a short circuit between the above-described positive electrode layer 302 and negative electrode layer 304, contains a solid electrolyte as a main component, and is a layer interposed between the above-described positive electrode active material layer and negative electrode active material layer. Examples of the solid electrolyte include a sulfide solid electrolyte, an oxide solid electrolyte, a polymer solid electrolyte, etc., and a sulfide solid electrolyte is preferably used.

[0031] Examples of sulfide solid electrolytes include, for example, LiI-Li2S-SiS2, LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li2S-P2S5, LiI-Li3PS4, LiI-LiBr-Li3PS4, Li3PS4, Li6PS5Cl, Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-Li2O, Li2S-P2S5-Li2OLiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-ZmSn (where m and n are positive numbers and Z is any of Ge, Zn, Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li x MO y (where x and y are positive numbers and M is any of P, Si, Ge, B, Al, Ga, In), etc. Note that the description of "Li2S-P2S5" means a sulfide solid electrolyte formed using a raw material composition containing Li2S and P2S5, and the same applies to other descriptions.

[0032] The sulfide solid electrolyte may, for example, have a Li3PS4 skeleton, a Li4P2S7 skeleton, or a Li4P2S6 skeleton. Examples of sulfide solid electrolytes having a Li3PS4 skeleton include LiI-Li3PS4, LiI-LiBr-Li3PS4, and Li3PS4. Also, examples of sulfide solid electrolytes having a Li4P2S7 skeleton include, for example, a Li-P-S-based solid electrolyte called LPS (e.g., Li7P3S 11 ). Also, as the sulfide solid electrolyte, for example, Li (4-x) Ge (1-x) P x S4 (where x satisfies 0 < x < 1), such as LGPS, may be used. Among them, the sulfide solid electrolyte is preferably a sulfide solid electrolyte containing the P element, and more preferably a material mainly composed of Li2S-P2S5. Furthermore, the sulfide solid electrolyte may contain a halogen (F, Cl, Br, I).

[0033] Also, when the sulfide solid electrolyte is of the Li2S-P2S5 system, the ratio of Li2S and P2S5 is preferably in the range of Li2S:P2S5 = 50:50 to 100:0 in terms of molar ratio, and more preferably Li2S:P2S5 = 70:30 to 80:20. Further, the sulfide solid electrolyte may be a sulfide glass, a crystallized sulfide glass, or a crystalline material obtained by a solid-phase method. The sulfide glass can be obtained, for example, by performing mechanical milling (such as a ball mill) on a raw material composition. Also, the crystallized sulfide glass can be obtained, for example, by performing heat treatment on the sulfide glass at a temperature equal to or higher than the crystallization temperature. The ionic conductivity (for example, Li ion conductivity) of the sulfide solid electrolyte at room temperature (25 °C) is preferably, for example, 1×10 -5 S / cm or more, and more preferably 1×10 -4 S / cm or more. The value of the ionic conductivity of the solid electrolyte can be measured by an alternating current impedance method.

[0034] Examples of the oxide solid electrolyte include compounds having a NASICON-type structure. As an example of a compound having a NASICON-type structure, compounds represented by the general formula Li 1+x Al x Ge 2-x (PO4)3 (0 ≤ x ≤ 2) (LAGP), compounds represented by the general formula Li 1+x Al x Ti 2-x (PO4)3 (0 ≤ x ≤ 2) (LATP), etc. are included. Also, as other examples of the oxide solid electrolyte, LiLaTiO (for example, Li 0.34 La 0.5 1TiO3), LiPON (for example, Li 2.9 PO 3.3 N 0.46 ), LiLaZrO (for example, Li7La3Zr2O 12) and the like. In addition to the solid electrolyte described above, the electrolyte layer 303 may further contain a binder. The binder is not particularly limited, and for example, those described above can be used.

[0035] The content of the solid electrolyte is preferably, for example, in the range of 10 to 100% by mass, more preferably in the range of 50 to 100% by mass, and even more preferably in the range of 90 to 100% by mass.

[0036] As described above, the positive electrode layer 302 used in this embodiment contains a sulfur compound as a positive electrode active material, so a sulfur-based material is used. The electrolyte layer 303 contains a sulfide solid electrolyte as a main component, so a sulfur material is used. The sulfur-based material may be used in either one of the positive electrode layer 302 and the electrolyte layer 303.

[0037] Then, as shown in FIG. 4(b), the positive electrode layer 302 and the negative electrode layer 304 are alternately laminated with the electrolyte layer 303 interposed therebetween, and the electrolyte layer 303 is further laminated on the uppermost layer and the lowermost layer thereof, respectively, whereby the power generation element 301 is formed.

[0038] The power generation element 301 configured as described above is housed and sealed in the upper exterior member 307 and the lower exterior member 308. The upper exterior member 307 and the lower exterior member 308 for sealing the power generation element 301 are formed of a flexible material such as a resin film of polyethylene or polypropylene, or a resin-metal thin film laminate material obtained by laminating both sides of a metal foil such as aluminum with a resin such as polyethylene or polypropylene. By thermally fusing these upper exterior member 307 and lower exterior member 308, the power generation element 301 is sealed with the positive electrode tab 305 and the negative electrode tab 306 led to the outside.

[0039] Note that on the positive electrode tab 305 and the negative electrode tab 306, a seal film 309 is provided at the portion in contact with the upper exterior member 307 and the lower exterior member 308 to ensure the adhesion with the upper exterior member 307 and the lower exterior member 308. The seal film 309 is not particularly limited, but for example, it can be composed of a synthetic resin material excellent in electrolyte resistance and heat fusibility such as polyethylene, modified polyethylene, polypropylene, modified polypropylene, or ionomer.

[0040] As shown in FIGS. 2 and 3, the battery case 10 includes a bottom frame 11, a plurality (four in this example) of plate-shaped side frames 12a to 12d fixed to the outer peripheral portion of the bottom frame 11, and a cover member 13 covering the side frames 12a to 12d. When the battery pack 1 is mounted on the automobile 2, the cover member 13 is located between the floor back surface 21 of the automobile body 20 and the battery 3. The bottom frame 11, the side frames 12a to 12d, and the cover member 13 are not particularly limited, but can be formed of extruded aluminum products.

[0041] As shown in FIG. 2, the bottom frame 11 is a plate-shaped member having a rectangular planar shape. As shown in FIG. 3, the bottom frame 11 has a first main surface 11a and a second main surface 11b on the opposite side thereof. In a state where it is assembled to the automobile body 20, the first main surface 11a corresponds to the upper surface, and the second main surface 11b corresponds to the lower surface. The bottom frame 11 has a mounting portion 111 and a step portion 112 provided at a position lower than the mounting portion 111.

[0042] The mounting portion 111 is a portion on which the battery 3 is mounted. In the present embodiment, the mounting portion 111 is provided at the central portion 111a of the bottom frame 11. A step portion 112 is provided outside the mounting portion 111.

[0043] As shown in FIGS. 2 and 3, the stepped portion 112 has a rectangular frame-shaped planar shape and is provided on the outer peripheral portion 112a of the bottom frame 11. As shown in FIG. 3, this stepped portion 112 is provided at a position lower than the placement portion 111. The first main surface 11a of the stepped portion 112 is recessed in a direction away from the cover member 13 with respect to the first main surface 11a of the placement portion 111, so that the height of the stepped portion 112 is lower than the height of the placement portion 111.

[0044] This stepped portion 112 has a plurality (four in this example) of flat portions 113 located at the corners 14 of the battery case 10 and a plurality (four in this example) of inclined portions 114 located between the flat portions 113. The flat portions 113 are arranged at the four corners of the stepped portion 112 and have a flat first main surface 11a. On the other hand, the inclined portions 114 are arranged on the four sides of the stepped portion 112 and have an inclined first main surface 11a. This inclined portion 114 has inclined surfaces 114b and 114c that are inclined such that the height continuously decreases from the top 114a in the first main surface 11a as it approaches the flat portion 113.

[0045] An adsorbent 115 capable of adsorbing hydrogen sulfide gas is arranged on the flat portion 113 of the bottom frame 11. The material constituting this adsorbent 115 is not particularly limited, but a material that chemically or physically adsorbs hydrogen sulfide gas can be used. As a material that chemically adsorbs hydrogen sulfide gas, although not particularly limited, alkaline substances such as NaOH, KOH, Ca(OH)2, or Mg(OH)2 can be used. As a material that chemically adsorbs hydrogen sulfide gas, although not particularly limited, activated carbon or silica gel can be used. Also, although not particularly shown, the adsorbent 115 may be housed inside at least a container capable of introducing outside air from the outside to the inside.

[0046] In this embodiment, the adsorbents 115 are arranged at each of the four corners 14 of the bottom (bottom surface frame 11) of the battery case 10, but the present invention is not limited thereto. For example, the adsorbents 115 may be arranged at one to three corners 14. Alternatively, the adsorbents 115 may be arranged at the outer peripheral portion 112a other than the corners 14.

[0047] Also, in this embodiment, one adsorbent 115 is arranged at each corner 14, but a plurality of adsorbents 115 may be arranged. Alternatively, a plurality of adsorbents 115 may be arranged side by side over the entire outer peripheral portion 112a of the bottom surface frame 11.

[0048] The cover member 13 is provided with a ventilation port 131 for discharging gas from the battery case 10. This ventilation port 131 is a hole that penetrates the cover member 13 along the thickness direction of the cover member 13. Since the ventilation port 131 is formed on the upper surface of the battery case 10, the gas existing in the upper part inside the battery case 10 is mainly discharged from the ventilation port 131.

[0049] Also, the ventilation port 131 of this embodiment is located at the outer peripheral portion of the cover member 13 and faces the stepped portion 112 of the bottom surface frame 11. Note that the ventilation port 131 may be located at the central portion of the cover member 13 and face the placement portion 111 of the bottom surface frame 11.

[0050] For the battery pack 1 as described above, the hydrogen sulfide gas generated from the battery 3 can be efficiently processed for the following reasons. First, the hydrogen sulfide gas has a higher specific gravity than air. Therefore, the hydrogen sulfide gas tends to stay in the lower part of the battery case 10. Also, when the vehicle 2 is turning, the inertial force on the hydrogen sulfide gas is relatively larger than the inertial force on the air. So, when the vehicle 2 turns, the hydrogen sulfide gas is more likely to move compared to the air. Thus, the hydrogen sulfide gas will flow on the outer peripheral portion 112a of the bottom frame 11 at the lower part of the battery case 10. Specifically, for example, when the vehicle 2 turns right forward, the hydrogen sulfide gas flows along the side frames 12a, 12b in the outer peripheral portion 112a toward the left rear direction and moves toward the left rear corner 14 inside the battery case 10. Similarly, when the vehicle 2 turns in a direction other than the right forward direction, the hydrogen sulfide gas moves toward the right front, left front, and right rear corners 14 in the outer peripheral portion 112a.

[0051] In this way, as the vehicle 2 turns, the hydrogen sulfide gas flows along the side frames 12a - 12d in the outer peripheral portion 112a of the battery case 10. Therefore, in the battery pack 1 of this embodiment, by arranging the adsorbent 115 on the outer peripheral portion 112a of the bottom frame 11, the hydrogen sulfide gas can be adsorbed and removed. Thus, an increase in the concentration of the hydrogen sulfide gas inside the battery case 10 can be suppressed.

[0052] Also, in this embodiment, in order to move the hydrogen sulfide gas toward the adsorbent 115 by utilizing the turning of the vehicle 2, even a small amount of hydrogen sulfide gas generated during the normal use of the vehicle 2 can be removed.

[0053] Moreover, by providing the adsorbent 115 on the outer peripheral portion 112a where the hydrogen sulfide gas tends to stay, the cost can be reduced compared to, for example, the method of wrapping the periphery of the battery module with the adsorbent. Also, since there is no need to provide a fan for flowing the hydrogen sulfide gas to a specific position, the cost can be reduced.

[0054] In particular, hydrogen sulfide gas tends to accumulate at the corner 14 of the battery case 10 when the vehicle 2 turns. Therefore, in this embodiment, in particular, by disposing the adsorbent 115 at the corner 14, the hydrogen sulfide gas that has moved to the corner 14 can be efficiently removed.

[0055] Also, in this embodiment, the adsorbent 115 is disposed at the stepped portion 112 located below the placement portion 111 on which the battery 3 is placed. As described above, since hydrogen sulfide gas has a higher specific gravity than air, hydrogen sulfide gas tends to accumulate at the stepped portion. Therefore, by disposing the adsorbent 115 at the stepped portion 112 as in this embodiment, hydrogen sulfide gas can be efficiently removed.

[0056] Also, in this embodiment, inclined surfaces 114b and 114c are formed at the stepped portion 112 such that the height continuously decreases as it approaches the adsorbent 115. For this reason, the hydrogen sulfide gas generated from the battery 3 is easily guided to the adsorbent 115, and the hydrogen sulfide gas can be efficiently removed.

[0057] Also, in this embodiment, a ventilation port 131 is provided in the cover member 13 that constitutes the upper surface of the battery case 10. For this reason, it becomes difficult for the hydrogen sulfide gas having a large specific gravity to be discharged from this ventilation port 131, and it becomes difficult for the hydrogen sulfide gas to leak to the outside of the battery pack 1.

[0058] As described above, the embodiments of the present invention have been described. However, these embodiments are described to facilitate the understanding of the present invention and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

[0059] For example, although the battery case 10 of the above embodiment has a rectangular planar shape, it is not limited thereto, and it may have a planar shape of a polygonal shape other than a quadrilateral. Also in this case, the vicinity of the corners of the polygon becomes the corner portions, and ventilation openings can be provided at the corner portions. Further, in the above embodiment, ventilation openings are provided at all the corner portions, but it is not limited thereto, and ventilation openings may be provided only at some of the plurality of corner portions.

Explanation of Signs

[0060] 1…Battery pack 10…Battery case 11…Bottom frame 11a…First main surface 11b…Second main surface 111…Mounting portion 111a…Central portion 112…Step portion 112a…Outer peripheral portion 113…Flat portion 114…Inclined portion 114a…Top portion 114b, 114c…Inclined surfaces 115…Adsorbent 12a~12d…Side frames 13…Cover member 131…Ventilation opening 14…Corner portion 2…Automobile 20…Automobile body 21…Underfloor surface 22…Dash panel 23…Front floor panel 24…Rear floor panel 25…Sill 3…Battery 30…All-solid-state battery

Claims

1. A battery pack mounted on a moving body, a battery case that houses a all-solid-state battery containing a sulfur-based material in a positive electrode and / or a solid electrolyte therein, an adsorbent disposed at the bottom within the battery case for adsorbing hydrogen sulfide gas, the adsorbent being disposed at the outer peripheral portion of the bottom, the battery case having a bottom surface frame on which the all-solid-state battery is placed, the bottom surface frame, a placement portion on which the all-solid-state battery is placed, and a stepped portion provided at the outer peripheral portion of the bottom surface frame and having a height lower than that of the placement portion. A battery pack having the same.

2. The battery pack according to claim 1, wherein the adsorbent is provided at a corner of the battery case at the outer peripheral portion. A battery pack.

3. The battery pack according to claim 1, wherein the stepped portion has an inclined surface that inclines such that the height decreases as it approaches a corner of the battery case. A battery pack.

4. A battery pack mounted on a moving body, a battery case that houses a all-solid-state battery containing a sulfur-based material in a positive electrode and / or a solid electrolyte therein, an adsorbent disposed at the bottom within the battery case for adsorbing hydrogen sulfide gas, the adsorbent being disposed at the outer peripheral portion of the bottom, and further comprising a ventilation port provided on the upper surface of the battery pack. A battery pack.

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