This application is based on and claims the benefit of priority from Japanese Patent Application No. 2022-140198, filed on 2 Sep. 2022, the content of which is incorporated herein by reference.
The present invention relates to a laminate type solid-state battery.
In recent years, research and development have been conducted on secondary batteries that contribute to energy efficiency, in order to ensure more people have access to reliable, sustainable, and advanced energy at an affordable price. As a secondary battery, a solid battery using a solid electrolyte as an electrolyte has attracted attention.
The solid-state battery has an electrode laminate in which a positive electrode, a solid electrolyte, and a negative electrode are laminated. A technology for covering laminate end surfaces of the electrode laminate with an insulating resin in order to prevent damage and ensure insulation is disclosed (for example, see Patent Document 1).
As a casing body that accommodates the electrode laminate, there is known a laminate casing body produced by welding one or two laminate films.
Conventional technology, including the technology disclosed in Patent Document 1, includes insulating members 31g and 32g each having a square shape in a cross-sectional view arranged at end portions of the electrode laminate, as shown in
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laminate type solid-state battery capable of preferably accommodating an electrode laminate.
(1) A first aspect of the present disclosure relates to a laminate type solid-state battery including: an electrode laminate; and a casing body being formed of a laminate film and accommodating the electrode laminate, the casing body including an insulating member disposed in an interior thereof, the insulating member abutting at least one of laminate end surfaces of the electrode laminate, the insulating member having at least one inclined surface that outwardly inclines from the electrode laminate in a cross-sectional view along a lamination direction, the inclined surface and a laminate surface of the electrode laminate forming an angle greater than 90° and less than 180°.
According to the first aspect, it is possible to provide a laminate type solid-state battery capable of preferably accommodating the electrode laminate.
(2) A second aspect of the present disclosure relates to the laminate type solid-state battery as described in the first aspect, in which the at least one inclined surface includes a plurality of inclined surfaces.
According to the second aspect, it is possible to provide a laminate type solid-state battery capable of more preferably accommodating the electrode laminate.
(3) A third aspect of the present disclosure relates to the laminate type solid-state battery as described in the first or second aspect, in which the inclined surface has a curved surface.
According to the third aspect, it is possible to provide a laminate type solid-state battery capable of more preferably accommodating the electrode laminate.
(4) A fourth aspect of the laminate type solid-state battery as described in the first or second aspect, in which the casing body has a welding portion, and in the interior of the casing body, a H2S absorbent material and/or H2O absorbent material is disposed between the insulating member and the welding portion.
According to the fourth aspect, it is possible to prevent water from intruding into the interior of the casing body to generate hydrogen sulfide, whereby the casing body is prevented from expanding and damaging the welding portion of the casing body.
(5) A fifth aspect of the present disclosure relates to the laminate type solid-state battery as described in the first or second aspect, in which the casing body is formed of a sheet of laminate film, and the insulating member abutting one of laminate end surfaces of the electrode laminate has a planar portion along the laminating direction of the electrode laminate, the one of laminate end surfaces of the electrode laminate being in a side in which the welding portion of the casing body is not formed.
According to the fifth aspect of the present disclosure, a plurality of laminate type solid-state batteries can be easily modularized.
As shown in
[Electrode Laminate]
(Negative Electrode Layer)
The negative electrode current collector 211 is not particularly limited as long as it has function of collecting electric current of the negative electrode layer, and examples of materials of the negative electrode current collector include nickel, copper, and stainless steel. Examples of the shape of the negative electrode current collector include a foil shape, a plate shape, etc. The negative electrode current collector 211 is electrically connected to a negative electrode terminal 21 in
A negative electrode active material layer 212 is a layer containing a negative electrode active material as an essential component. The negative electrode active material is not particularly limited as long as it can occlude and release a charge transfer medium and examples thereof include lithium transition metal oxides such as lithium titanate (Li4Ti5O12), transition metal oxides such as TiO2, Nb2O3 and WO3, metal sulfides, metal nitrides, carbon materials such as graphite, soft carbon and hard carbon, metallic lithium, metallic indium, and lithium alloys. The negative electrode active material may be in the form of a powder or a thin film. The negative electrode active material layer 212 may contain a conductive aid for improving conductivity and a binder in addition to the negative electrode active material. As the conductive aid and the binder, materials generally used in solid-state batteries can be used.
(Intermediate Layer)
The intermediate layer 213 is a layer laminated between the negative electrode active material layer 212 and the solid electrolyte layer 23. By providing the intermediate layer 213, non-uniform metal deposition between the negative electrode active material layer 212 and the solid electrolyte layer 23 can be suppressed. The intermediate layer 213 is not particularly limited as long as it is a layer having electron conductivity and ion conductivity, and materials generally used for solid-state batteries can be used.
(Solid Electrolyte Layer)
The solid electrolyte layer 23 is a layer containing at least a solid electrolyte material. The charge transfer medium conduction between the positive electrode active material and the negative electrode active material can be performed through the solid electrolyte material included in the solid electrolyte layer.
The solid electrolyte material is not particularly limited as long as it has charge transfer medium conductivity, i.e., ion conductivity, and examples thereof include a sulfide solid electrolyte material, an oxide solid electrolyte material, a nitride solid electrolyte material, and a halide solid electrolyte material.
Examples of the sulfide solid electrolyte material include Li2S—P2S5, Li2S—P2S5—LiI, etc. in the case of lithium ion batteries. The recitation “Li2S—P2S5” means a sulfide solid electrolyte material using a raw material composition containing Li2S and P2S5.
As examples of the oxide solid electrolyte material, an NASICON type oxide, a garnet type oxide, and a perovskite type oxide can be mentioned in the case of lithium ion batteries.
As examples of the NASICON type oxide, oxides containing Li, Al, Ti, P and O (for example, Li1.5Al0.5Ti1.5(PO4)3) can be mentioned. As examples of the garnet type oxide, oxides containing Li, La, Zr and O (for example, Li7La3Zr2O12) can be mentioned. As examples of the perovskite type oxide, oxides containing Li, La, Ti and O (for example, LiLaTiO3) may be mentioned.
(Positive Electrode Layer)
The positive electrode current collector 221 is not particularly limited as long as it has function of collecting current of the positive electrode layer, and examples thereof include aluminum, aluminum alloy, stainless steel, nickel, iron, and titanium, among which aluminum, aluminum alloy, and stainless steel are preferable. Examples of the shape of the positive electrode current collector include a foil shape and a plate shape. The positive electrode current collector 221 is electrically connected to a positive electrode terminal 22 in
A positive electrode active material layer 222 is a layer containing at least a positive electrode active material. The positive electrode active material contained in the positive electrode active material layer 222 can be the same as that used for a positive electrode layer of a general solid-state battery and is not particularly limited. In the case of lithium ion batteries, examples include a layered active material containing lithium, a spinel type active material, and an olivine type active material. Specific examples of the positive electrode active material include lithium cobaltate (LiCoO2), lithium nickelate (LiNiO2), LiNipMnqCorO2 (p+q+r=1), LiNipAlqCorO2 (p+q+r=1), lithium manganate (LiMn2O4), a hetero atom-substituted Li—Mn spinel represented by Li1+xMn2−x−yMyO4 (x+y=2, M=at least one selected from Al, Mg, Co, Fe, Ni, or Zn), lithium titanate (an oxide containing Li and Ti), and metallic lithium phosphate (LiMPO4, M=at least one selected from Fe, Mn, Co, or Ni).
The positive electrode active material layer 222 may optionally contain a solid electrolyte from the viewpoint of improving charge transfer medium conductivity. Further, a binder, a conductive aid, and the like may be contained. As these matters, those generally used in solid-state batteries can be used.
[Casing Body]
The casing bodies 41 and 42 are formed of laminate film, and accommodate the electrode laminate 2. The laminate film has a multilayer structure in which a thermally fusible resin layer made of polyolefin or the like is laminated on the surface of a metal layer made of aluminum, stainless steel (SUS), or the like. In addition to the above, a laminate cell may have a layer made of a polyamide such as nylon, a polyester such as polyethylene terephthalate, or the like, an adhesive layer made of any laminate adhesive, or the like.
In the present embodiment, the casing body includes two casing bodies 41 and 42, which are laminate film, the electrode laminate 2 is disposed between the two casing bodies 41 and 42, and the electrode laminate 2 and the insulating members 31 and 32 are sealed by welding portions j1 and j2 formed by welding the casing bodies 41 and 42.
[Insulating Members]
As shown in
Material of the insulating members 31 and 32 is not particularly limited as long as it has insulating property, but from the viewpoint of ease of processing and disposition, it is preferable to use an insulating resin as the material. Examples of the insulating resin include fluorine-based rubber, silicon-based rubber, styrene-butadiene rubber, and an acrylic resin.
The insulating members 31 and 32 are arranged to abut at least one of the laminate end surfaces of the electrode laminate 2.
In addition to the surfaces abutting the laminate end surfaces of the electrode laminate 2, the insulating members 31 and 32 each have an inclined surface, in a cross-sectional view along the laminate direction L, that inclines from the electrode laminate 2 toward the welding portion j1 or j2, which is in the outside. The inclined surfaces incline from one end side and the other end side of surfaces that abut the laminate end surfaces of the electrode laminate 2 in
Here, a structure of a laminate type solid-state battery 1g according to the prior art will be described with reference to
By the insulating members 31 and 32 according to the present embodiment, it is possible to reduce the stress applied to the corner portions formed on the laminate end surfaces during sealing of the laminate film. Therefore, occurrence of wrinkles and cracks in the casing bodies 41 and 42 during manufacturing of the laminate type solid-state battery 1 is suppressed. Further, since the stress applied to the welding portion j1 or j2 during sealing can also be reduced, the welding failure of the welding portion j1 or j2 can be reduced.
In
In the present embodiment, the insulating members 31 and 32 have a triangular shape composed of a side that abuts the electrode laminate 2 in a cross-sectional view along the laminate direction L, and two side other than the above. Accordingly, the insulating members 31 and 32 each have a substantially triangular prism shape as a three-dimensional shape, and corner portions c1 are formed at both ends of the surfaces on which each of the insulating members 31 and 32 abuts the electrode laminate 2.
[Method of Manufacturing Laminate Type Solid-State Battery]
The method of manufacturing the laminate type solid-state battery 1 according to the present embodiment includes: forming the electrode laminate 2; forming the insulating members 31 and 32; and arranging the electrode laminate 2 and the insulating members 31 and 32 between the casing bodies 41 and 42 and welding the casing bodies at the welding portions j1 and j2 to seal the electrode laminate 2 and the insulating members 31 and 32 in the interior of the casing bodies 41 and 42.
A method of manufacturing the electrode laminate 2 may include: forming a laminate unit (lamination units 2a, 2b, and 2c in
The forming of the insulating members 31 and 32 may include, for example, arranging the electrode laminate 2 in the interior of a frame body that has a shape corresponding to shapes of the electrode laminate 2 and the insulating members 31 and 32; filling the gap with a material such as an insulating resin to constitute the insulating members 31 and 32; curing the material; and then removing the frame body.
The arranging of the electrode laminate 2 and the insulating members 31 and 32 between the casing bodies 41 and 42 and welding the casing bodies at the welding portions j1 and j2 and sealing is not particularly limited, but a known heat sealing method or the like can be used.
Next, a laminate type solid-state battery according to another embodiment of the present invention will be described. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof may be omitted.
As shown in
Insulating members 31a and 32a according to the second embodiment have a pentagonal shape in a cross-sectional view along the lamination direction L, including a side abutting the electrode laminate 2 and four sides other than the above. Accordingly, the insulating members 31a and 32a have a substantially pentagonal prism shape as a three-dimensional shape, and corner portions c2 are formed at both ends of the surfaces on which each of the insulating members 31a and 32a abuts the electrode laminate 2. Corner portions c3 are formed between the inclined surfaces of the insulating members 31a and 32a.
As shown in
The insulating members 31b and 32b according to the third embodiment have a substantially pentagonal shape in a cross-sectional view along the lamination direction L, including a side abutting the electrode laminate 2 and four sides other than the above. Accordingly, the insulating members 31b and 32b have a substantially pentagonal prism shape as a three-dimensional shape, and corner portions c4 are formed at both ends of the surfaces on which each of the insulating members 31b and 32b abuts the electrode laminate 2. Corner portions c5 are formed between the inclined surfaces of the insulating members 31b and 32b.
As shown in
Insulating members 31c and 32c according to a fourth embodiment have a substantially semicircular shape in a cross-sectional view along the lamination direction L, including a side abutting the electrode laminate 2 and the curved surface other than the above. Accordingly, the insulating members 31c and 32c have a substantially semi-cylindrical shape as a three-dimensional shape.
As shown in
The laminate type solid-state battery 1d according to the present embodiment includes insulating members 31d and 32d. In the interior of the casing bodies 41 and 42, an absorbent material 5 is disposed between the insulating member 31d or 32d and the welding portion j1 or j2, respectively. The absorbent material 5 is a H2S absorbent and/or a H2O absorbent. In a case a sulfide-based solid electrolyte material is used as the solid electrolyte material, if water penetrates into the inside of the casing body 41 or 42, the sulfide-based solid electrolyte material may react with water to generate hydrogen sulfide, which may cause the casing body 41 or 42 to expand, resulting in rupture. Since the absorbent material 5 can absorb water that has penetrated from the outside or hydrogen sulfide generated, the above-described situation can be prevented.
As shown in
In the sixth embodiment, the insulating member 31e that abuts a laminate end surface in a side in which the welding portion j1 is not formed has a side that abuts the electrode laminate 2, two inclined surfaces that outwardly incline from the electrode laminate 2, and a planar portion formed between the two inclined surfaces. The planar portion is a plane along the lamination direction L. Since the insulating member 31e has a plane along the lamination direction L, the casing body can be formed by a sheet of the casing body 41e. Further, since a plane 41f along the planar portion is also formed in the casing body 41e, the plane 41f can be disposed in contact with a module constituent member 61 as shown in
[Solid Battery Module]
Next, the configuration of a solid-state battery module 10 formed by stacking a plurality of laminate type solid-state batteries if according to the present embodiment will be described with reference to
In the heat transfer material 61 and the lower plate 62, holes 61a and 62a corresponding to the shape of the insulating member 32b of the laminate type solid-state battery if are formed. Since the casing body 41h is not provided with a welding portion in the side in which the insulating member 32b is to be disposed, a plurality of laminate type solid-state batteries if can be easily fixed by inserting an end surface of each laminate type solid-state battery if in the side in which the insulating member 32b is to be disposed, into holes 61a and 62a, which correspond to the shape of the insulating member 32b.
Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.
Number | Date | Country | Kind |
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2022-140198 | Sep 2022 | JP | national |