Battery material, and bipolar battery

Abstract

To provide a battery material capable of preventing peeling.SOLUTION: A battery material includes a first member, an adhesive layer, and a second member. The adhesive layer contains an adhesive, a conductive additive, and porous particles. The adhesive contains a base agent and a hardener, in which, for 100 parts by mass of the base agent, 5.0 parts by mass or more and 10 parts by mass or less of the curing agent, 0.1 parts by mass or more and 1.0 part by mass or less of the conductive additive, and 90 parts by mass or more and 200 parts by mass or less of the porous particles are contained.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a battery component, a bipolar battery, and a method for manufacturing the battery component. [Background technology]

[0002] Patent Document 1 (JP 2019-034466 A) discloses a gas barrier film laminate in which films are laminated via an adhesive to prevent foaming when the adhesive is cured. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-034466 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to provide superior secondary batteries, research has been conducted on the components (battery components) of secondary batteries. In this research, a technology for bonding different battery components via an adhesive layer has been developed.

[0005] However, air bubbles may be generated in the adhesive layer during bonding, which may result in a decrease in adhesive strength, etc. As a result, there is a risk of the battery components peeling off.

[0006] An object of the present disclosure is to suppress peeling of battery components. [Means for solving the problem]

[0007] [1] A first member, an adhesive layer, and a second member in this order; the adhesive layer includes an adhesive, a conductive additive, and porous particles; The adhesive includes a base agent and a curing agent.

[0008] The bubbles that form in the adhesive layer are caused by gases such as carbon dioxide and moisture. Therefore, by having the porous particles adsorb these gases and moisture, the formation of bubbles can be suppressed, and as a result, peeling of the battery components can be suppressed.

[0009] [2] The base material is a resin having a carboxyl group, The battery member according to [1], wherein the curing agent is a resin having an isocyanate group or an amino group.

[0010] [3] The battery member according to [1] or [2], containing 5.0 parts by mass or more and 10 parts by mass or less of the curing agent, 0.1 parts by mass or more and 1.0 parts by mass or less of the conductive additive, and 90 parts by mass or more and 200 parts by mass or less of the porous particles relative to 100 parts by mass of the main agent.

[0011] [4] The battery member according to any one of [1] to [3], wherein the first member and the second member are current collectors.

[0012] [5] A bipolar battery comprising the battery component according to [4]. [6] A step of preparing a slurry by mixing a base agent, a curing agent, a conductive additive, porous particles, and a solvent; applying the slurry to a first member; drying the slurry applied to the first member to form an adhesive layer; and placing a second member on the adhesive layer; The method for manufacturing a battery component, wherein the first member and the second member are laminated via the adhesive layer. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a battery member according to the present embodiment. [Figure 2] FIG. 2 is a flowchart showing an outline of the method for manufacturing a battery component in this embodiment. [Figure 3] FIG. 3 is a conceptual diagram showing an example of a manufacturing apparatus used to manufacture the battery component in this embodiment. [Figure 4] FIG. 4 is a conceptual diagram showing an example of a lithium ion secondary battery according to this embodiment. [Figure 5] FIG. 5 is a table showing the first battery configuration. [Figure 6] FIG. 6 is a table showing the second battery configuration. [Figure 7] FIG. 7 is a table showing the third battery configuration. [Figure 8] FIG. 8 is a conceptual diagram showing an example of a bipolar battery according to this embodiment. [Figure 9] FIG. 9 is a photograph showing the appearance of the battery components in Example 1 after heating. [Figure 10] FIG. 10 is a photograph of the appearance of the battery components in Comparative Example 1 after heating. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present disclosure (hereinafter may be abbreviated as "the present embodiment") and an example of the present disclosure (hereinafter may be abbreviated as "the present example") will be described. However, the present embodiment and the example do not limit the technical scope of the present disclosure.

[0015] The stoichiometric composition formula indicates a representative example of a compound. The compound may have a non-stoichiometric composition. For example, "Al2O3" is not limited to a compound having a substance ratio (molar ratio) of "Al / O = 2 / 3." Unless otherwise specified, "Al2O3" indicates a compound containing Al and O in any composition ratio. Furthermore, for example, the compound may be doped with a trace element, or a portion of Al and O may be substituted with another element.

[0016] The term "derivative" refers to a compound in which a part of a parent compound has been modified by at least one method selected from the group consisting of the introduction of a functional group, atomic substitution, oxidation, reduction, and other chemical reactions. The modification may be at one or more locations. The "substituent" may include at least one selected from the group consisting of, for example, alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, unsaturated cycloalkyl groups, aromatic groups, heterocyclic groups, halogen atoms (such as F, Cl, Br, and I), OH groups, SH groups, CN groups, SCN groups, OCN groups, nitro groups, alkoxy groups, unsaturated alkoxy groups, amino groups, alkylamino groups, dialkylamino groups, aryloxy groups, acyl groups, alkoxycarbonyl groups, acyloxy groups, aryloxycarbonyl groups, acylamino groups, alkoxycarbonylamino groups, aryloxycarbonylamino groups, sulfonylamino groups, sulfamoyl groups, carbamoyl groups, alkylthio groups, arylthio groups, sulfonyl groups, sulfinyl groups, ureido groups, phosphoric acid amide groups, sulfo groups, carboxy groups, hydroxamic acid groups, sulfino groups, hydrazino groups, imino groups, and silyl groups. These substituents may be further substituted. When there are two or more substituents, the substituents may be the same or different, and multiple substituents may be bonded to each other to form a ring.

[0017] The "copolymer" includes at least one selected from the group consisting of unspecified type, statistical type, random type, alternating type, periodic type, block type, and graft type.

[0018] <<Battery components>> Fig. 1 is a cross-sectional view showing an example of a battery member according to the present embodiment. As shown in Fig. 1, a battery member 10 includes a first member 1, an adhesive layer 3, and a second member 2 in this order.

[0019] The adhesive layer 3 may be disposed on the entire surface in contact with the first member 1 and the entire surface in contact with the second member 2, or may be disposed on at least a part of the surface in contact with the first member 1 and the entire surface in contact with the second member 2. From the viewpoint of the peel strength of the battery member 10, it is preferable that the adhesive layer 3 be disposed on the entire surface in contact with the first member 1 and the entire surface in contact with the second member 2.

[0020] The battery component 10 may include a plurality of adhesive layers 3. For example, the battery component 10 may include, in this order, an adhesive layer 3, a first component 1, an adhesive layer 3, and a second component 2; or may include, in this order, a first component 1, an adhesive layer 3, a second component 2, and an adhesive layer 3; or may include, in this order, an adhesive layer 3, a first component 1, an adhesive layer 3, a second component 2, and an adhesive layer 3.

[0021] <Adhesive layer> The adhesive layer 3 includes an adhesive 4, a conductive material 5, and porous particles 6. The adhesive 4 includes a base agent and a curing agent.

[0022] Main ingredient From the viewpoint of good moldability, a thermoplastic resin is preferably used as the base material. Furthermore, from the viewpoint of resistance to the electrolytic solution, the base material is preferably a resin having a carboxyl group. Examples of resins having a carboxyl group include polyester resins having a carboxyl group, polyamide resins having a carboxyl group, polyurethane resins having a carboxyl group, acrylic resins having a carboxyl group, and polyolefin resins having a carboxyl group. These aqueous resins having a carboxyl group may be used alone or in combination of two or more. Among these, polyolefin resins having a carboxyl group are more preferred from the viewpoint of resistance to the electrolytic solution.

[0023] Hardener The curing agent is a material that hardens the base agent when mixed with it. From the viewpoint of resistance to the electrolyte, the curing agent is preferably a resin having an isocyanate group or an amino group. Examples of resins having an isocyanate group (hereinafter also referred to as "isocyanate-based resins") include aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, and araliphatic polyisocyanates, each having two or more isocyanate groups. Examples of resins having an amino group (hereinafter also referred to as "amine-based resins") include aliphatic amines, alicyclic amines, modified aliphatic polyamines, modified alicyclic amines, and polyamidoamines. Among these, aliphatic polyisocyanates are more preferred from the viewpoint of resistance to the electrolyte and ease of controlling the curing reaction.

[0024] The content of the curing agent is preferably 5.0 to 10 parts by mass, and more preferably 7.0 to 10 parts by mass, relative to 100 parts by mass of the base resin. When the content of the curing agent is 5.0 to 10 parts by mass, curing of the resin in the crosslinking reaction is promoted.

[0025] Conductive additives The conductive additive 5 can form an electron conduction path between the first member 1 and the second member 2. The conductive additive 5 can contain any component. For example, the conductive additive 5 may contain at least one selected from the group consisting of Ni-plated particles, acetylene black (AB), Ketjen Black (registered trademark), vapor-grown carbon fiber (VGCF), carbon nanotubes (CNT), and graphene flakes (GF). Among these, Ni-plated particles are preferred from the viewpoint of achieving both electrical conductivity and peel strength.

[0026] The content of the conductive additive 5 is preferably 0.1 to 1.0 part by mass, and more preferably 0.2 to 0.7 part by mass, relative to 100 parts by mass of the base material. By having the content of the conductive additive 5 be 0.1 to 1.0 part by mass, it is possible to achieve both electrical conductivity and peel strength.

[0027] 《Porous particles》 The porous particles 6 adsorb bubbles caused by gases such as carbon dioxide and moisture that are generated within the adhesive layer 3. Therefore, when the adhesive layer 3 contains the porous particles 6, the generation of bubbles can be suppressed, and peeling between the first member 1 and the second member 2 can be suppressed.

[0028] There are no particular limitations on the porous particles 6 as long as they can adsorb gas bubbles, and examples thereof include zeolite, silica, talc, kaolinite, feldspar, etc. Among these, zeolite is preferred from the viewpoint of gas adsorption capacity.

[0029] The content of the porous particles 6 is preferably 90 to 200 parts by mass, and more preferably 90 to 120 parts by mass, per 100 parts by mass of the base material. When the content of the porous particles 6 is 90 to 200 parts by mass, it is possible to prevent expansion due to gas adsorption and suppress a decrease in peel strength due to the specific surface area associated with gas adsorption.

[0030] <First member, second member> In this embodiment, examples of the first member 1 and the second member 2 include a positive electrode current collector, a positive electrode active material layer, a negative electrode current collector, and a negative electrode active material layer. The first member 1 and the second member 2 are different members. That is, when the first member 1 is a positive electrode current collector, the second member 2 is a positive electrode active material layer or a negative electrode current collector. When the first member 1 is a positive electrode active material layer, the second member 2 is a positive electrode current collector. When the first member 1 is a negative electrode current collector, the second member 2 is a positive electrode current collector or a negative electrode active material layer. When the first member 1 is a negative electrode active material layer, the second member 2 is a negative electrode current collector. When at least one of the first member 1 and the second member 2 is a positive electrode current collector and the other is a positive electrode active material layer, the battery member 10 is a positive electrode. When at least one of the first member 1 and the second member 2 is a negative electrode current collector and the other is a negative electrode active material layer, the battery member 10 is a negative electrode. When at least one of the first member 1 and the second member 2 is a positive electrode current collector and the other is a negative electrode current collector, the battery member 10 can constitute a bipolar electrode. Note that the examples given above are merely examples and are not intended to be limiting.

[0031] 《Positive electrode current collector》 The positive electrode current collector is conductive. The positive electrode current collector may have a thickness of, for example, 5 to 50 μm. The positive electrode current collector may include, for example, a metal foil. The positive electrode current collector may include, for example, at least one selected from the group consisting of Al, Mn, Ti, Fe, and Cr. The positive electrode current collector may include, for example, Al foil, Al alloy foil, Ti foil, stainless steel (SUS) foil, etc.

[0032] 《Cathode active material layer》 The positive electrode active material layer may have a thickness of, for example, 10 to 1000 μm, 50 to 500 μm, or 100 to 300 μm. The positive electrode active material layer contains a positive electrode active material. The positive electrode active material layer may further contain, for example, a conductive material, a binder, etc.

[0033] <Conductive material> The conductive material can form an electron conduction path in the positive electrode active material layer. The content of the conductive material can be, for example, 0.1 to 10 parts by mass relative to 100 parts by mass of the positive electrode active material. The conductive material can contain any component. For example, the conductive material can contain at least one selected from the group consisting of graphite, AB, Ketjen black, VGCF, CNT, and GF.

[0034] <Binder> The content of the binder may be, for example, 0.1 to 10 parts by mass per 100 parts by mass of the positive electrode active material. The binder may contain any component. For example, the binder may contain at least one selected from the group consisting of PVdF, vinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP), PTFE, CMC, PAA, PVA, PVP, polyoxyethylene alkyl ether, and derivatives thereof.

[0035] <Other ingredients> The positive electrode active material layer may further contain, for example, an inorganic filler, an organic filler, a solid electrolyte, a surface modifier, a dispersant, a lubricant, a flame retardant, a protective agent, a flux, a coupling agent, an adsorbent, etc. The positive electrode active material layer may also contain, for example, polyoxyethylene allyl phenyl ether phosphate, zeolite, a silane coupling agent, MoS2, WO3, etc.

[0036] <Cathode active material> The positive electrode active material may be, for example, in a particulate form. The positive electrode active material may have a D50 of, for example, 1 to 30 μm, 10 to 20 μm, or 1 to 10 μm. "D50" refers to the particle size at which the cumulative frequency from the smallest particle size reaches 50% in a volume-based particle size distribution. D50 can be measured by a laser diffraction method. The measurement sample is a powder.

[0037] The positive electrode active material may contain any component. The positive electrode active material may contain, for example, a transition metal oxide, a polyanion compound, etc. The composition within one particle (positive electrode active material) may be uniform or non-uniform. For example, the composition may be graded from the surface to the center of the particle. The composition may change continuously or discontinuously (in steps).

[0038] <Transition metal oxides: space group R-3m> The transition metal oxide may have any crystal structure. The transition metal oxide may include, for example, a crystal structure belonging to the space group R-3m. For example, a compound represented by the general formula "LiMO2" may have a crystal structure belonging to the space group R-3m. The transition metal oxide may be represented by, for example, the following formula (A-1):

[0039] Li 1-a Ni x M 1-x O2…(A-1) In the formula, the relationships of -0.5≦a≦0.5 and 0≦x≦1 are satisfied.

[0040] M may contain at least one selected from the group consisting of, for example, Co, Mn, and Al.

[0041] In the above formula (A-1), x may satisfy, for example, the relationship of 0 < x ≤ 0.1, 0.1 ≤ x ≤ 0.2, 0.2 ≤ x ≤ 0.3, 0.3 ≤ x ≤ 0.4, 0.4 ≤ x ≤ 0.5, 0.5 ≤ x ≤ 0.6, 0.6 ≤ x ≤ 0.7, 0.7 ≤ x ≤ 0.8, 0.8 ≤ x ≤ 0.9, or 0.9 ≤ x ≤ 1. a may satisfy, for example, the relationship of -0.4 ≤ a ≤ 0.4, -0.3 ≤ a ≤ 0.3, -0.2 ≤ a ≤ 0.2, or -0.1 ≤ a ≤ 0.1.

[0042] The transition metal oxide may contain, for example, at least one selected from the group consisting of LiCoO2, LiMnO2, LiNi 0.9 Co 0.1 O2, LiNi 0.9 Mn 0.1 O2, and LiNiO2.

[0043] 〈NCM〉 The transition metal oxide may be represented by, for example, the following formula (A-2). The compound represented by the following formula (A-2) may also be referred to as "NCM".

[0044] Li 1-a Ni x Co y Mn z O2…(A-2) In the formula, the relationships of -0.5 ≤ a ≤ 0.5, 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1 are satisfied.

[0045] In the above formula (A-2), x may satisfy, for example, the relationship of 0 < x ≤ 0.1, 0.1 ≤ x ≤ 0.2, 0.2 ≤ x ≤ 0.3, 0.3 ≤ x ≤ 0.4, 0.4 ≤ x ≤ 0.5, 0.5 ≤ x ≤ 0.6, 0.6 ≤ x ≤ 0.7, 0.7 ≤ x ≤ 0.8, 0.8 ≤ x ≤ 0.9, or 0.9 ≤ x < 1.

[0046] In the above formula (A-2), y may satisfy, for example, the relationship of 0 < y ≤ 0.1, 0.1 ≤ y ≤ 0.2, 0.2 ≤ y ≤ 0.3, 0.3 ≤ y ≤ 0.4, 0.4 ≤ y ≤ 0.5, 0.5 ≤ y ≤ 0.6, 0.6 ≤ y ≤ 0.7, 0.7 ≤ y ≤ 0.8, 0.8 ≤ y ≤ 0.9, or 0.9 ≤ y < 1.

[0047] In the above formula (A-2), z may satisfy, for example, the relationship of 0 < z ≤ 0.1, 0.1 ≤ z ≤ 0.2, 0.2 ≤ z ≤ 0.3, 0.3 ≤ z ≤ 0.4, 0.4 ≤ z ≤ 0.5, 0.5 ≤ z ≤ 0.6, 0.6 ≤ z ≤ 0.7, 0.7 ≤ z ≤ 0.8, 0.8 ≤ z ≤ 0.9, or 0.9 ≤ z < 1.

[0048] NCM is, for example, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, LiNi 0.4 Co 0.3 Mn 0.3 O2, LiNi 0.3 Co 0.4 Mn 0.3 O2, LiNi 0.3 Co 0.3 Mn 0.4 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.5 Co 0.3 Mn 0.2 O2, LiNi 0.5 Co 0.4 Mn 0.1 O2, LiNi 0.5 Co 0.1 Mn 0.4 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.6 Co 0.3 Mn 0.1 O2, LiNi 0.6 Co 0.1 Mn 0.3 O2, LiNi 0.7 Co 0.1 Mn 0.2 O2, LiNi 0.7 Co 0.2 Mn 0.1 O2, LiNi0.8 Co 0.1 Mn 0.1 O2, and LiNi 0.9 Co 0.05 Mn 0.05 It may contain at least one selected from the group consisting of O2.

[0049] 〈NCA〉 The transition metal oxide may be represented, for example, by the following formula (A-3). The compound represented by the following formula (A-3) may also be referred to as "NCA".

[0050] Li 1-a Ni x Co y Al z O2…(A-3) In the formula, the relationships of -0.5 ≦ a ≦ 0.5, 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1 are satisfied.

[0051] In the above formula (A-3), x may satisfy, for example, the relationship of 0 < x ≦ 0.1, 0.1 ≦ x ≦ 0.2, 0.2 ≦ x ≦ 0.3, 0.3 ≦ x ≦ 0.4, 0.4 ≦ x ≦ 0.5, 0.5 ≦ x ≦ 0.6, 0.6 ≦ x ≦ 0.7, 0.7 ≦ x ≦ 0.8, 0.8 ≦ x ≦ 0.9, or 0.9 ≦ x < 1.

[0052] In the above formula (A-3), y may satisfy, for example, the relationship of 0 < y ≦ 0.1, 0.1 ≦ y ≦ 0.2, 0.2 ≦ y ≦ 0.3, 0.3 ≦ y ≦ 0.4, 0.4 ≦ y ≦ 0.5, 0.5 ≦ y ≦ 0.6, 0.6 ≦ y ≦ 0.7, 0.7 ≦ y ≦ 0.8, 0.8 ≦ y ≦ 0.9, or 0.9 ≦ y < 1.

[0053] In the above formula (A-3), z may satisfy, for example, the relationship of 0 < z ≦ 0.1, 0.1 ≦ z ≦ 0.2, 0.2 ≦ z ≦ 0.3, 0.3 ≦ z ≦ 0.4, 0.4 ≦ z ≦ 0.5, 0.5 ≦ z ≦ 0.6, 0.6 ≦ z ≦ 0.7, 0.7 ≦ z ≦ 0.8, 0.8 ≦ z ≦ 0.9, or 0.9 ≦ z < 1.

[0054] NCA is, for example, LiNi 0.7 Co 0.1Al 0.2 O2, LiNi 0.7 Co 0.2 Al 0.1 O2, LiNi 0.8 Co 0.1 Al 0.1 O2, LiNi 0.8 Co 0.17 Al 0.03 O2, LiNi 0.8 Co 0.15 Al 0.05 O2 and LiNi 0.9 Co 0.05 Al 0.05 O2.

[0055] <Multi-component system> The positive electrode active material may contain, for example, two or more types of NCM. The positive electrode active material may contain, for example, NCM (0.6≦x) and NCM (x<0.6). "NCM (0.6≦x)" refers to a compound in which x (Ni ratio) in the above formula (A-2) is 0.6 or more. NCM (0.6≦x) may also be referred to as, for example, a "high nickel material." NCM (0.6≦x) is, for example, LiNi 0.8 Co 0.1 Mn 0.1 O2, etc. "NCM (x<0.6)" refers to a compound in which x (Ni ratio) is less than 0.6 in the above formula (A-2). NCM (x<0.6) is, for example, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, etc. The mixing ratio (mass ratio) of NCM(0.6≦x) and NCM(x<0.6) may be, for example, "NCM(0.6≦x) / NCM(x<0.6)=9 / 1 to 1 / 9," "NCM(0.6≦x) / NCM(x<0.6)=9 / 1 to 4 / 6," or "NCM(0.6≦x) / NCM(x<0.6)=9 / 1 to 3 / 7."

[0056] The positive electrode active material may contain, for example, NCA and NCM. The mixing ratio (mass ratio) of NCA and NCM may be, for example, "NCA / NCM = 9 / 1 to 1 / 9," "NCA / NCM = 9 / 1 to 4 / 6," or "NCA / NCM = 9 / 1 to 3 / 7." The Ni ratios of NCA and NCM may be the same or different. The Ni ratio of NCA may be higher than the Ni ratio of NCM. The Ni ratio of NCA may be lower than the Ni ratio of NCM.

[0057] <Transition metal oxides: space group C2 / m> The transition metal oxide may have, for example, a crystal structure belonging to the space group C2 / m. The transition metal oxide may be represented by, for example, the following formula (A-4).

[0058] Li2MO3…(A-4) In the formula, M may include, for example, at least one selected from the group consisting of Ni, Co, Mn, and Fe.

[0059] The positive electrode active material may include, for example, a mixture of LiMO2 (space group R-3m) and Li2MO3 (space group C2 / m), or a solid solution of LiMO2 and Li2MO3 (Li2MO3-LiMO2).

[0060] <Transition metal oxides: space group Fd-3m> The transition metal oxide may have, for example, a crystal structure belonging to the space group Fd-3m. The transition metal oxide may be represented by, for example, the following formula (A-5).

[0061] LiMn 2-x M x O4…(A-5) In the formula, the relationship 0≦x≦2 is satisfied.

[0062] M may include, for example, at least one selected from the group consisting of Ni, Fe, and Zn.

[0063] LiM2O4 (space group Fd-3m) is, for example, LiMn2O4 and LiMn 1.5 Ni 0.5 The positive electrode active material may contain at least one selected from the group consisting of LiMO2 (space group R-3m) and LiM2O4 (space group Fd-3m). The positive electrode active material may contain, for example, a mixture of LiMO2 (space group R-3m) and LiM2O4 (space group Fd-3m). The mixing ratio (mass ratio) of LiMO2 (space group R-3m) and LiM2O4 (space group Fd-3m) may be, for example, "LiMO2 / LiM2O4 = 9 / 1 to 9 / 1," "LiMO2 / LiM2O4 = 9 / 1 to 5 / 5," or "LiMO2 / LiM2O4 = 9 / 1 to 7 / 3."

[0064] <Polyanion Compounds> The polyanion compound may include, for example, a phosphate (such as LiFePO4), a silicate, a borate, etc. The polyanion compound may be represented, for example, by any of the following formulas (A-6) to (A-9).

[0065] LiMPO4…(A-6) Li 2-x MPO4F...(A-7) Li2MSiO4…(A-8) LiMBO3…(A-9) In the above formulas (A-6) to (A-9), M may include, for example, at least one selected from the group consisting of Fe, Mn, and Co. In the above formula (A-7), for example, the relationship 0≦x≦2 may be satisfied.

[0066] The positive electrode active material may contain, for example, a mixture of LiMO2 (space group R-3m) and a polyanionic compound. The mixing ratio (mass ratio) of LiMO2 (space group R-3m) and the polyanionic compound may be, for example, "LiMO2 / polyanionic compound = 9 / 1 to 9 / 1," "LiMO2 / polyanionic compound = 9 / 1 to 5 / 5," or "LiMO2 / polyanionic compound = 9 / 1 to 7 / 3."

[0067] Dopant A dopant may be added to the positive electrode active material. The dopant may be diffused throughout the particle or distributed locally. For example, the dopant may be unevenly distributed on the particle surface. The dopant may be a substitutional solid solution atom or an interstitial solid solution atom. The amount of dopant added (molar fraction relative to the entire positive electrode active material) may be, for example, 0.01 to 5%, 0.1 to 3%, or 0.1 to 1%. One type of dopant may be added, or two or more types of dopants may be added. Two or more types of dopants may form a composite.

[0068] The dopant may include at least one selected from the group consisting of, for example, B, C, N, halogen, Si, Na, Mg, Al, Mn, Co, Cr, Sc, Ti, V, Cu, Zn, Ga, Ge, Se, Sr, Y, Zr, Nb, Mo, In, Pb, Bi, Sb, Sn, W, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and actinides.

[0069] For example, the set "Zr, Mg, W, Sm", the set "Ti, Mn, Nb, Si, Mo", or the set "Er, Mg" may be added to the NCA.

[0070] For example, Ti may be added to the NCM. For example, a combination of "Zr, W", a combination of "Si, W", or a combination of "Zr, W, Al, Ti, Co" may be added to the NCM.

[0071] 《Negative electrode current collector》 The negative electrode current collector is conductive. The negative electrode current collector may have a thickness of, for example, 5 to 50 μm. The negative electrode current collector may include, for example, a metal foil. The negative electrode current collector may include, for example, at least one selected from the group consisting of Cu, Ni, Fe, Zn, Pb, Ag, and Au. The negative electrode current collector may include, for example, a Cu foil or a Cu alloy foil.

[0072] 《Negative electrode active material layer》 The negative electrode active material layer may have a thickness of, for example, 10 to 1000 μm, 50 to 500 μm, or 100 to 300 μm. The negative electrode active material layer contains a negative electrode active material. The negative electrode active material layer may further contain, for example, a conductive material, a binder, etc.

[0073] <Conductive material> The conductive material can form an electron conduction path in the negative electrode active material layer. The content of the conductive material may be, for example, 0.1 to 10 parts by mass relative to 100 parts by mass of the negative electrode active material. The conductive material may contain any component. The conductive material may include, for example, at least one selected from the group consisting of graphite, AB, Ketjen black, VGCF, CNT, and GF. The CNT may include at least one selected from the group consisting of single-walled CNT (SWCNT) and multi-walled CNT (MWCNT).

[0074] <Binder> The content of the binder may be, for example, 0.1 to 10 parts by mass per 100 parts by mass of the negative electrode active material. The binder may contain any component. For example, the binder may contain at least one selected from the group consisting of styrene butadiene rubber (SBR), acrylate butadiene rubber (ABR), sodium alginate, carboxymethyl cellulose (CMC-H, CMC-Na, CMC-Li, CMC-NH4, etc.), polyacrylic acid (PAA-H, PAA-Na, PAA-Li, etc.), polyacrylonitrile (PAN), polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), acrylic resin (acrylic acid ester copolymer), methacrylic resin (methacrylic acid ester copolymer), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), and derivatives thereof. For example, "CMC-Na" refers to the Na salt of CMC. For example, "CMC-H" refers to acid-type CMC. The same is true for "PAA-Na" etc.

[0075] <Other ingredients> The negative electrode active material layer may further contain, for example, an inorganic filler, an organic filler, a solid electrolyte, a surface modifier, a dispersant, a lubricant, a flame retardant, a protective agent, a flux, a coupling agent, an adsorbent, etc. The negative electrode active material layer may also contain, for example, a layered silicate (smectite, montmorillonite, bentonite, hectorite, etc.), an inorganic filler (solid alumina, hollow silica, boehmite, etc.), a polysiloxane compound, etc.

[0076] <Negative electrode active material> Examples of the negative electrode active material include natural graphite, artificial graphite, soft carbon, hard carbon, silicon (Si), SiO, Li silicate, Si-based alloy, tin (Sn), SnO, Sn-based alloy, and Li4Ti5O 12 It may contain at least one selected from the group consisting of:

[0077] <Carbon-based active material> "Graphite" is a general term for natural graphite and artificial graphite. Graphite may be a mixture of natural graphite and artificial graphite. The mixing ratio (mass ratio) may be, for example, "natural graphite / artificial graphite = 1 / 9 to 9 / 1," "natural graphite / artificial graphite = 2 / 8 to 8 / 2," or "natural graphite / artificial graphite = 3 / 7 to 7 / 3."

[0078] The graphite may contain a dopant. The dopant may include, for example, at least one selected from the group consisting of B, N, P, Li, and Ca. The amount of the dopant added may be, for example, 0.01 to 5%, 0.1 to 3%, or 0.1 to 1%, in mole fraction.

[0079] The surface of graphite may be coated with, for example, amorphous carbon. The surface of graphite may be coated with, for example, a different material. The different material may contain, for example, at least one selected from the group consisting of P, W, Al, and O. The different material may be, for example, Al(OH)3, AlOOH, Al2O3, WO3, Li2CO3, LiHCO 3、 and Li3PO4.

[0080] 〈Alloy-based active material〉 SiO may be represented, for example, by the following formula (B-1).

[0081] SiO x …(B-1) In the formula, the relationship 0 < x < 2 is satisfied.

[0082] In the above formula (B-1), x may satisfy, for example, 0.5 ≤ x ≤ 1.5, or 0.8 ≤ x ≤ 1.2.

[0083] The Li silicate may include, for example, at least one selected from the group consisting of Li4SiO4, Li2SiO3, Li2Si2O5, and Li8SiO6. The second negative electrode active material may include, for example, a mixture of Si and Li silicate. The mixing ratio (mass ratio) may be, for example, "Si / Li silicate = 1 / 9 to 9 / 1", "Si / Li silicate = 2 / 8 to 8 / 2", "Si / Li silicate = 3 / 7 to 7 / 3", or "Si / Li silicate = 4 / 6 to 6 / 4".

[0084] The alloy-based active material (Si, SiO, etc.) may contain an additive. The additive may be, for example, a substitutional solid solution atom or an interstitial solid solution atom. The additive may be an adherent adhering to the surface of the alloy-based active material. The adherent may be, for example, a simple substance, an oxide, a carbide, a nitride, a halide, etc. The addition amount may be, in mole fraction, for example, 0.01 to 5%, 0.1 to 3%, or 0.1 to 1%. The additive may include, for example, at least one selected from the group consisting of Li, Na, K, Rb, Be, Mg, Ca, Sr, Fe, Ba, B, Al, Ga, In, C, Ge, Sn, Pb, N, P, As, Y, Sb, and S. That is, SiO may be doped with Mg and Na. For example, Mg silicate and Na silicate may be formed. For example, boron oxide (e.g., B2O3), yttrium oxide (e.g., Y2O3, etc.) may be added to SiO.

[0085] 〈Si-C composite material〉 The negative electrode active material may include, for example, a composite material of a carbon-based active material (such as graphite) and an alloy-based active material (such as Si). A composite material containing Si and carbon may also be called a "Si-C composite material." For example, Si fine particles may be dispersed in carbon particles. For example, Si fine particles may be dispersed in graphite particles. For example, Li silicate particles may be coated with a carbon material (such as amorphous carbon). A Si-C composite material and graphite may be mixed and used.

[0086] <Multi-component system> The negative electrode active material may contain two or more components. The negative electrode active material may contain a carbon-based active material (such as graphite) and an alloy-based active material (such as Si or SiO). The mixing ratio (mass ratio) of the carbon-based active material to the alloy-based active material may be, for example, "carbon-based active material / alloy-based active material=1 / 9 to 9 / 1," "carbon-based active material / alloy-based active material=2 / 8 to 8 / 2," "carbon-based active material / alloy-based active material=3 / 7 to 7 / 3," or "carbon-based active material / alloy-based active material=4 / 6 to 6 / 4."

[0087] <Method of manufacturing battery components> Fig. 2 is a flowchart showing an outline of a method for manufacturing a battery component according to this embodiment. Fig. 3 is a conceptual diagram showing an example of a manufacturing apparatus used in manufacturing the battery component according to this embodiment. As shown in Fig. 2, the method for manufacturing a battery component according to this embodiment includes at least (a) preparing a slurry, (b) applying the slurry, (c) forming an adhesive layer, and (d) arranging a second component. The first component and the second component are laminated with the adhesive layer interposed therebetween.

[0088] (a) Preparation of Slurry In this step, a slurry containing a base agent, a curing agent, a conductive additive, porous particles, and a solvent is prepared. For example, the slurry is prepared by mixing the base agent, the curing agent, the conductive additive, the porous particles, and the solvent.

[0089] (b) Application of Slurry In this step, the slurry is applied to the first member. The application method is not particularly limited, and examples thereof include dip coating, spray coating, roll coating, doctor blade coating, gravure coating, and screen printing. As an example, in FIG. 3, the slurry is applied to one side of the first member 1 by a gravure roll 11.

[0090] (c) Formation of Adhesive Layer In this step, the slurry applied to the first member is dried to form an adhesive layer. The drying method is not particularly limited, and the slurry may be dried, for example, in a drying oven or the like. As an example, in FIG. 3, the slurry is dried in a hot air drying oven. The drying temperature may be adjusted appropriately. The drying temperature may be, for example, 100 to 200°C.

[0091] (d) Arrangement of the second member In this step, the second member is placed on the adhesive layer. At this time, the second member is placed so that the first member, adhesive layer, and second member are arranged in this order. There are no particular limitations on the placement method, and for example, the second member may be placed on the adhesive layer by roll pressing. Furthermore, heat pressing is preferable because heating improves the adhesion between the adhesive layer and the second member. As an example, in FIG. 3, the second member 2 is placed on the adhesive layer by a pair of heated rolls 13. The pressure and temperature of the press may be adjusted as appropriate. The pressure of the press may be, for example, 0.3 to 1.0 MPa. The temperature of the press may be, for example, 50 to 150°C.

[0092] <<Lithium-ion secondary battery>> 4 is a conceptual diagram showing an example of a lithium ion secondary battery according to this embodiment. The lithium ion secondary battery 100 includes a power generating element 50 and an electrolyte (not shown).

[0093] As shown in Fig. 4, in the lithium-ion secondary battery 100 of this embodiment, an adhesive layer 23 is preferably provided between the positive electrode current collector 21 and the positive electrode active material layer 22. Similarly, an adhesive layer 33 is preferably provided between the negative electrode current collector 31 and the negative electrode active material layer 32. This configuration suppresses peeling between the current collector and the active material layer. Furthermore, it is preferable to provide an adhesive layer between the current collector and the active material layer of at least one of the positive electrode 20 and the negative electrode 30, but it is more preferable to provide an adhesive layer between the current collector and the active material layer in both the positive electrode 20 and the negative electrode 30.

[0094] <Exterior body> The lithium ion secondary battery 100 may include an exterior body (not shown). The exterior body may house the power generating element 50 and the electrolyte. The exterior body may have any shape. For example, the exterior body may be a metal case or a pouch made of a metal foil laminate film. The case may have any shape. For example, the case may be cylindrical, rectangular, flat, coin-shaped, or the like. The exterior body may contain, for example, Al. The exterior body may house, for example, one power generating element 50, or may house multiple power generating elements 50. The multiple power generating elements 50 may form, for example, a series circuit or a parallel circuit. Within the exterior body, the multiple power generating elements 50 may be stacked in the thickness direction of the lithium ion secondary battery 100.

[0095] <Power generation elements> The power generating element 50 may also be referred to as an "electrode group," an "electrode body," or the like. The power generating element 50 includes a positive electrode 20 and a negative electrode 30. The power generating element 50 may further include a separator 40. The separator 40 is disposed between the positive electrode 20 and the negative electrode 30. The power generating element 50 may have any configuration. The power generating element 50 may be, for example, a laminated type. For example, the power generating element 50 may be formed by alternately stacking the positive electrodes 20 and the negative electrodes 30 with the separator 40 sandwiched between them. The power generating element 50 may be, for example, a wound type. For example, a laminate may be formed by stacking a strip-shaped positive electrode 20, a strip-shaped separator 40, and a strip-shaped negative electrode 30. The laminate may be spirally wound to form the power generating element 50. The wound type power generating element 50 may be formed into a flat shape after winding.

[0096] <Positive electrode> The positive electrode 20 may be, for example, in the form of a sheet. The positive electrode 20 may include, for example, a positive electrode current collector 21 and a positive electrode active material layer 22. Details of the positive electrode current collector 21 and the positive electrode active material layer 22 are as described above.

[0097] <Surface coating> The positive electrode 20 may include composite particles. The composite particles include a core particle and a coating layer. The core particle includes a positive electrode active material. The coating layer covers at least a portion of the surface of the core particle. The coating layer may have a thickness of, for example, 1 to 3,000 nm, 5 to 2,000 nm, 10 to 1,000 nm, 10 to 100 nm, or 10 to 50 nm. The thickness of the coating layer can be measured, for example, from an SEM image of the particle cross section. That is, a sample is prepared by embedding the composite particles in a resin material. The sample is cross-sectioned using an ion milling device. For example, an ion milling device manufactured by Hitachi High-Technologies Corporation, product name: ArBlade (registered trademark) 5000 (or equivalent), may be used. The cross section of the sample is observed using an SEM. For example, an SEM device manufactured by Hitachi High-Technologies Corporation, product name: SU8030 (or equivalent), may be used. The thickness of the coating layer is measured in 20 fields for each of 10 composite particles, and the arithmetic mean of the thicknesses of 200 points in total is used.

[0098] The proportion of the surface of the core particle that is covered with the coating layer is also referred to as the "coverage." The coverage may be, for example, 1% or more, 10% or more, 30% or more, 50% or more, or 70% or more. The coverage may be, for example, 100% or less, 90% or less, or 80% or less.

[0099] The coverage can be measured, for example, by XPS (X-ray Photoelectron Spectroscopy). For example, an XPS device manufactured by ULVAC-PHI, Inc., product name: PHI X-tool (or an equivalent product) may be used. A sample powder consisting of composite particles is placed in the XPS. Narrow scan analysis is performed. The measurement data is processed by analysis software. For example, analysis software manufactured by ULVAC-PHI, Inc., product name: MulTiPak (or an equivalent product) may be used. By analyzing the measurement data, multiple elements are detected. The ratio of each detected element is calculated from the area of ​​each peak. The coverage can be calculated using the following formula (C-1).

[0100] θ={I1 / (I0+I1)}×100 …(C-1) θ: Coverage rate [%] I0: Ratio of elements originating from the core particle I1: Ratio of elements derived from the coating layer For example, if the core particle contains NCM, I0 indicates the total element ratio of "Ni, Co, Mn." For example, if the core particle contains NCA, I0 indicates the total element ratio of "Ni, Co, Al." For example, if the coating layer contains P and B, I1 indicates the total element ratio of "P, B."

[0101] The coating layer may contain any component. The coating layer may contain, for example, an element, an organic substance, an inorganic acid salt, an organic acid salt, a hydroxide, an oxide, a carbide, a nitride, a sulfide, a halide, or the like. The coating layer may contain, for example, B, Al, W, Zr, Ti, Co, F, lithium compounds (e.g., Li2CO3, LiHCO3, LiOH, Li2O, etc.), tungsten oxide (e.g., WO3, etc.), titanium oxide (e.g., TiO2, etc.), zirconium oxide (e.g., ZrO2), boron oxide, boron phosphate (e.g., BPO4, etc.), aluminum oxide (e.g., Al2O3, etc.), boehmite, aluminum hydroxide, phosphate (e.g., Li3PO 4、 (NH4)3PO4, AlPO4), borates (e.g., Li2B4O7, LiBO3, etc.), polyacrylates (Li salts, Na salts, NH4 salts, etc.), acetates (e.g., Li salts, etc.), CMC (CMC-Na, CMC-Li, CMC-NH4, etc.), LiNbO 3、 It may contain at least one selected from the group consisting of Li2TiO3 and Li-containing halides (for example, LiAlCl4, LiTiAlF6, LiYBr6, LiYCl6, etc.).

[0102] <Hollow particles / solid particles> "Hollow particles" refer to secondary particles in which, in a cross-sectional image, the area of ​​the cavity in the center is 30% or more of the cross-sectional area of ​​the entire particle. The proportion of the cavity in a hollow particle may be, for example, 40% or more, 50% or more, or 60% or more. "Solid particles" refer to secondary particles in which, in a cross-sectional image of the particle, the area of ​​the cavity in the center is less than 30% of the cross-sectional area of ​​the entire particle. The proportion of the cavity in a solid particle may be, for example, 20% or less, 10% or less, or 5% or less. The positive electrode active material may be either hollow particles or solid particles. A mixture of hollow particles and solid particles may be used. The mixing ratio (mass ratio) of hollow particles to solid particles may be, for example, "hollow particles / solid particles = 1 / 9 to 9 / 1," "hollow particles / solid particles = 2 / 8 to 8 / 2," "hollow particles / solid particles = 3 / 7 to 7 / 3," or "hollow particles / solid particles = 4 / 6 to 6 / 4."

[0103] <Large particles / Small particles> "Electrode active material" is a general term for positive electrode active material and negative electrode active material. The electrode active material may have, for example, a unimodal particle size distribution (number basis). The electrode active material may have, for example, a multimodal particle size distribution. The electrode active material may have, for example, a bimodal particle size distribution. That is, the electrode active material may contain large particles and small particles. When the particle size distribution is bimodal, the particle diameter corresponding to the peak top of the larger particle diameter is the particle diameter of the large particles (d L The particle size corresponding to the peak top of the smaller particle size is considered to be the particle size of the small particles (d S ) is considered as the particle size ratio (d L / d S ) may be, for example, 2 to 10, 2 to 5, or 2 to 4. L may be, for example, 8 to 20 μm or 8 to 15 μm. S may be, for example, 1 to 10 μm, or 1 to 5 μm.

[0104] For example, the particle size distribution may be subjected to peak separation processing using waveform analysis software. L ) and the peak area due to small particles (S S) is expressed as, for example, "S L / S S =1 / 9~9 / 1", "S L / S S =5 / 5~9 / 1" or "S L / S S =7 / 3~9 / 1" is also acceptable.

[0105] The number-based particle size distribution is measured by microscopy. Multiple cross-sectional samples are taken from the electrode active material layer. The cross-sectional samples may include, for example, cross sections perpendicular to the surface of the electrode active material layer. For example, the surface to be observed is cleaned by ion milling or the like. The cross-sectional samples are observed using an SEM. The observation magnification is adjusted so that 10 to 100 particles fit within the observation field. The Feret diameters of all particles in the image are measured. The "Feret diameter" refers to the distance between the two most distant points on the particle's contour. By observing multiple cross-sectional samples, a total of 1,000 or more Feret diameters are obtained. A number-based particle size distribution is created from the 1,000 or more Feret diameters.

[0106] A bimodal particle size distribution can be formed by mixing two types of particles. The two types of particles have different particle size distributions. For example, the two types of particles may have different D50s. For example, the large particles may have a D50 of 8 to 20 μm or 8 to 15 μm. For example, the small particles may have a D50 of 1 to 10 μm or 1 to 5 μm. The ratio of the D50 of the large particles to the D50 of the small particles may be, for example, 2 to 10, 2 to 5, or 2 to 4. The mixing ratio (mass ratio) of the large particles to the small particles may be, for example, "large particles / small particles = 1 / 9 to 9 / 1," "large particles / small particles = 5 / 5 to 9 / 1," or "large particles / small particles = 7 / 3 to 9 / 1."

[0107] The large particles and the small particles may have the same composition or different compositions. For example, the large particles may be NCA and the small particles may be NCM. For example, the large particles may be NCM (0.6≦x) and the small particles may be NCM (x<0.6).

[0108] <Negative electrode> The negative electrode 30 may be, for example, in the form of a sheet. The negative electrode 30 may include, for example, a negative electrode current collector 31 and a negative electrode active material layer 32. Details of the negative electrode current collector 31 and the negative electrode active material layer 32 are as described above.

[0109] <separator> The separator 40 can separate the positive electrode 20 from the negative electrode 30. The separator 40 has electrical insulation properties. The separator 40 may include, for example, at least one selected from the group consisting of a resin film, an inorganic particle layer, and an organic particle layer. The separator 40 may include, for example, a resin film and an inorganic particle layer.

[0110] Resin film The resin film is porous. The resin film may include, for example, a microporous film, a nonwoven fabric, etc. The resin film includes a resin skeleton. The resin skeleton may be continuous, for example, in a network form. Pores are formed in the gaps in the resin skeleton. The resin film can allow electrolytes to pass through. The resin film may have, for example, an average pore size of 1 μm or less. The resin film may have, for example, an average pore size of 0.01 to 1 μm, or 0.1 to 0.5 μm. The "average pore size" can be measured by mercury intrusion porosimetry. The resin film may have, for example, a pore size of 50 to 250 s / 100 cm. 3 The "Gurley value" can be measured by the Gurley test method.

[0111] The resin film may contain at least one selected from the group consisting of, for example, olefin-based resins, polyurethane-based resins, polyamide-based resins, cellulose-based resins, polyether-based resins, acrylic-based resins, and polyester-based resins. The resin film may contain at least one selected from the group consisting of, for example, polyethylene (PE), polypropylene (PP), polyamide (PA), polyamideimide (PAI), polyimide (PI), aromatic polyamide (aramid), polyphenylene ether (PPE), and derivatives thereof. The resin film may be formed by, for example, a stretching method, a phase separation method, or the like. The resin film may have a thickness of, for example, 5 to 50 μm or 10 to 25 μm.

[0112] The resin film may have, for example, a single-layer structure. The resin film may be made of, for example, a PE layer. The skeleton of the PE layer is formed of PE. The PE layer may have a shutdown function. The resin film may have, for example, a multi-layer structure. The resin film may include, for example, a PP layer and a PE layer. The skeleton of the PP layer is formed of PP. The resin film may have, for example, a three-layer structure. The resin film may be formed by laminating, for example, a PP layer, a PE layer, and a PP layer in this order. The thickness of the PE layer may be, for example, 5 to 20 μm. The thickness of the PP layer may be, for example, 3 to 10 μm.

[0113] 《Inorganic particle layer》 The inorganic particle layer may be formed on the surface of the resin film. The inorganic particle layer may be formed on only one side of the resin film, or on both the front and back sides. The inorganic particle layer may be formed on the surface facing the positive electrode 20, or on the surface facing the negative electrode 30. The inorganic particle layer may be formed on the surface of the positive electrode 20, or on the surface of the negative electrode 30.

[0114] The inorganic particle layer is porous. The inorganic particle layer contains inorganic particles. The inorganic particles may also be referred to as "inorganic filler." Pores are formed in the gaps between the inorganic particles. The inorganic particle layer may have a thickness of, for example, 0.5 to 10 μm, or 1 to 5 μm. The inorganic particles may contain, for example, a heat-resistant material. An inorganic particle layer containing a heat-resistant material is also referred to as an "HRL (Heat Resistance Layer)." The inorganic particles may contain at least one type selected from the group consisting of boehmite, alumina, zirconia, titania, magnesia, silica, and the like. The inorganic particles may have any shape. The inorganic particles may be, for example, spherical, rod-like, plate-like, fibrous, or the like. The inorganic particles may have a D50 of, for example, 0.1 to 10 μm, or 0.5 to 3 μm. The inorganic particle layer may further contain a binder. The binder may contain, for example, at least one selected from the group consisting of acrylic resins, polyamide resins, fluorine resins, aromatic polyether resins, and liquid crystal polyester resins.

[0115] 《Organic particle layer》 The separator 40 may include, for example, an organic particle layer. The separator 40 may include, for example, an organic particle layer instead of a resin film. The separator 40 may include, for example, an organic particle layer instead of an inorganic particle layer. The separator 40 may include both a resin film and an organic particle layer. The separator 40 may include both an inorganic particle layer and an organic particle layer. The separator 40 may include a resin film, an inorganic particle layer, and an organic particle layer.

[0116] The organic particle layer may have a thickness of, for example, 0.1 to 50 μm, 0.5 to 20 μm, 0.5 to 10 μm, or 1 to 5 μm. The organic particle layer contains organic particles. The organic particles may also be referred to as "organic filler." The organic particles may contain a heat-resistant material. The organic particles may contain at least one selected from the group consisting of, for example, PE, PP, PTFE, PI, PAI, PA, and aramid. The organic particles may be, for example, spherical, rod-like, plate-like, fibrous, or the like. The organic particles may have a D50 of, for example, 0.1 to 10 μm or 0.5 to 3 μm.

[0117] Separator 40 may include, for example, a mixed layer, which includes both inorganic and organic particles.

[0118] <Electrolytes> The electrolyte has dissolved therein Li ions. The electrolyte may be a liquid electrolyte or a gel electrolyte. The liquid electrolyte may contain, for example, an electrolytic solution. The electrolytic solution contains a solvent and a solute.

[0119] "solvent" <Ether solvents> The electrolytic solution may contain, for example, an ether-based solvent. The solvent may contain, for example, a hydrofluoroether (HFE). The HFE may contain, for example, at least one selected from the group consisting of a difluoromethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, a 2,2,3,3,3-pentafluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, a 1,1,1,3,3,3-hexafluoroisopropyl group, a 1,1,2,3,3,3-hexafluoropropyl group, a 2,2,3,3,4,4,4-heptafluorobutyl group, a 2,2,3,3,4,4-hexafluorobutyl group, and a 2,2,3,3,4,4,5,5-octafluoropentyl group.

[0120] The solvent may also contain an ether other than HFE (hereinafter also referred to as "second ether"). The second ether may contain, for example, at least one selected from the group consisting of tetrahydrofuran (THF), 1,4-dioxane (DOX), 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), ethylglyme, triglyme, tetraglyme, and derivatives thereof. The solvent may contain, for example, 1 to 50% by volume of the second ether (DME, etc.), with the balance being HFE. The solvent may contain, for example, 10 to 40% by volume of the second ether, with the balance being HFE.

[0121] <Carbonate solvent> The electrolytic solution may contain, for example, a carbonate-based solvent (carbonate ester-based solvent). The solvent may contain, for example, a cyclic carbonate, a chain carbonate, a fluorinated carbonate, or the like. The solvent may contain, for example, at least one selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), monofluoroethylene carbonate (FEC), difluoroethylene carbonate, 4,4-difluoroethylene carbonate, trifluoroethylene carbonate, perfluoroethylene carbonate, fluoropropylene carbonate, difluoropropylene carbonate, and derivatives thereof.

[0122] The solvent may contain a cyclic carbonate (EC, PC, FEC, etc.) and a chain carbonate (EMC, DMC, DEC, etc.). The mixing ratio (volume ratio) of the cyclic carbonate to the chain carbonate may be, for example, "cyclic carbonate / chain carbonate = 1 / 9 to 4 / 6," "cyclic carbonate / chain carbonate = 2 / 8 to 3 / 7," or "cyclic carbonate / chain carbonate = 3 / 7 to 4 / 6."

[0123] The solvent may contain a cyclic carbonate (EC, PC, etc.) and a fluorinated cyclic carbonate (FEC, etc.). The mixing ratio (volume ratio) of the cyclic carbonate to the fluorinated cyclic carbonate may be, for example, "cyclic carbonate / fluorinated cyclic carbonate = 99 / 1 to 90 / 10", "cyclic carbonate / fluorinated cyclic carbonate = 9 / 1 to 1 / 9", "cyclic carbonate / fluorinated cyclic carbonate = 9 / 1 to 7 / 3", or "cyclic carbonate / fluorinated cyclic carbonate = 3 / 7 to 1 / 9".

[0124] The solvent may contain, for example, EC, FEC, EMC, DMC, and DEC. The volume ratio of each component may satisfy, for example, the relationship represented by the following formula (D-1).

[0125] V EC +V FEC +V EMC +V DMC +V DEC =10 ...(D-1) In the formula, V EC , V FEC , V EMC , V DMC , V DEC indicates the volume ratio of EC, FEC, EMC, DMC, and DEC, respectively.

[0126] 1≦V EC ≦4, 0≦V FEC ≦3, V EC +V FEC ≦4, 0≦V EMC ≦9, 0≦V DMC ≦9, 0≦V DEC ≦9, 6≦V EMC +V DMC +V DEC ≦9 The relationship is satisfied.

[0127] In the above formula (D-1), For example, 1 ≤ V EC ≦2, or 2≦V EC The relationship ≦3 may be satisfied.

[0128] For example, 1 ≤ V FEC ≦2, or 2≦V FEC The relationship ≦4 may be satisfied. For example, 3≦V EMC ≦4, or 6≦V EMC The relationship ≦8 may be satisfied.

[0129] For example, 3≦V DMC ≦4, or 6≦V DMC The relationship ≦8 may be satisfied. For example, 3≦V DEC ≦4, or 6≦V DEC The relationship ≦8 may be satisfied.

[0130] The solvent may have a composition, for example, in volume ratios of "EC / EMC=3 / 7," "EC / DMC=3 / 7," "EC / FEC / DEC=1 / 2 / 7," "EC / DMC / EMC=3 / 4 / 3," "EC / DMC / EMC=3 / 3 / 4," "EC / FEC / DMC / EMC=2 / 1 / 4 / 3," "EC / FEC / DMC / EMC=1 / 2 / 4 / 3," "EC / FEC / DMC / EMC=2 / 1 / 3 / 4," or "EC / FEC / DMC / EMC=1 / 2 / 3 / 4."

[0131] <Additives> The electrolyte may contain any additive. The amount of additive (mass fraction relative to the total amount of the electrolyte) may be, for example, 0.01 to 5%, 0.05 to 3%, or 0.1 to 1%. The additive may include, for example, an SEI (Solid Electrolyte Interphase) formation accelerator, an SEI formation inhibitor, a gas generator, an overcharge inhibitor, a flame retardant, an antioxidant, an electrode protectant, a surfactant, etc.

[0132] Examples of the additives include vinylene carbonate (VC), vinyl ethylene carbonate (VEC), 1,3-propane sultone (PS), tert-amylbenzene, 1,4-di-tert-butylbenzene, biphenyl (BP), cyclohexylbenzene (CHB), ethylene sulfite (ES), propane sultone (PS), ethylene sulfate (DTD), γ-butyrolactone, phosphazene compounds, carboxylic acid esters (e.g., methyl formate (MF), methyl acetate (MA), methyl propionate (MP), diethyl malonate (DEM), etc.), fluorobenzenes (e.g., monofluorobenzene (FB), 1,2-difluorobenzene, 1,3-difluorobenzene, 1,4-difluorobenzene, 1,2,3-trifluorobenzene, 1,2,4-trifluorobenzene, 1,3,5-trifluorobenzene, 1,2,3,4-tetrafluorobenzene, 1,2,3,5-tetrafluorobenzene, 1,2,4,5-tetrafluorobenzene, pentafluorobenzene, hexafluorobenzene, etc.), fluorotoluenes (e.g., 2-fluorotoluene, 3-fluorotoluene, 4-fluorotoluene, 2,3-difluorotoluene, 2,4-difluorotoluene, 2,5-difluorotoluene, 2,6-difluorotoluene, 3,4-difluorotoluene, octafluorotoluene, etc.), benzotrifluorides (e.g., benzotrifluoride, 2-fluorobenzotrifluoride, 3-fluorobenzotrifluoride, 4-fluorobenzotrifluoride, 2-methylbenzotrifluoride, 3-methylbenzotrifluoride, 4-methylbenzotrifluoride, etc.), fluoroxylenes (e.g., 3-fluoro-o-xylene, 4-fluoro-o-xylene, 2-fluoro-m-xylene, 5-fluoro-m-xylene, etc.), sulfur-containing heterocyclic compounds (e.g., benzothiazole, 2-methylbenzotrifluoride, The solvent may contain at least one selected from the group consisting of benzotriazole, benzotriazole, tetrathiafulvalene, etc.), nitrile compounds (e.g., adiponitrile, succinonitrile, etc.), phosphate esters (e.g., trimethyl phosphate, triethyl phosphate, etc.), carboxylic acid anhydrides (e.g., acetic anhydride, propionic anhydride, oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, benzoic anhydride, etc.), alcohols (e.g., methanol, ethanol, n-propyl alcohol, ethylene glycol, diethylene glycol monomethyl ether, etc.), and derivatives thereof.

[0133] The components described above as solutes and solvents may be used as minor components (additives). The additives may include, for example, at least one selected from the group consisting of LiBF, LiFSI, LiTFSI, LiBOB, LiDFOB, LiDFOP, LiPOF, FSOLi, LiI, LiBr, HFE, DOX, PC, FEC, and derivatives thereof.

[0134] Ionic liquids The liquid electrolyte may contain an ionic liquid. The liquid electrolyte may contain, for example, at least one selected from the group consisting of sulfonium salts, ammonium salts, pyridinium salts, piperidinium salts, pyrrolidinium salts, morpholinium salts, phosphonium salts, imidazolium salts, and derivatives thereof.

[0135] Gel electrolyte The gel electrolyte may include a liquid electrolyte and a polymer material. The polymer material may form a polymer matrix. The polymer material may include, for example, at least one selected from the group consisting of PVdF, PVdF-HFP, PAN, PVdF-PAN, polyethylene oxide (PEO), polyethylene glycol (PEG), and derivatives thereof.

[0136] <Battery configuration> FIG. 5 is a table showing the first battery configuration. FIG. 6 is a table showing the second battery configuration. FIG. 7 is a table showing the third battery configuration. In each table, when multiple materials are listed in a box, the listing includes each material alone and combinations thereof. For example, when materials "α, β, γ" are listed in a box, the listing indicates "at least one selected from the group consisting of α, β, and γ." Any element may be extracted from the first to third cell configurations and combined in any desired manner.

[0137] This embodiment may be incorporated into, for example, the first to third battery configurations. The positive electrode in the first battery configuration may be replaced with the positive electrode (positive electrode current collector 21, positive electrode active material layer 22) in this embodiment. Battery performance may be improved by combining the first to third battery configurations with this embodiment.

[0138] <<Bipolar battery>> 8 is a conceptual diagram showing an example of a bipolar battery in this embodiment. A bipolar battery 130 includes power generating elements 120 and 121 and an electrolyte (not shown). Note that explanations that overlap with those of the lithium ion secondary battery described above will be omitted.

[0139] Each of the power generating elements 120 and 121 includes a positive electrode current collector 112, a positive electrode active material layer 113, a separator 116, a negative electrode active material layer 115, and a negative electrode current collector 114, arranged in this order along the thickness direction. In each pair of power generating elements 120 and 121, an adhesive layer 111 is disposed between the positive electrode current collector 112 of the power generating element 120 and the negative electrode current collector 114 of the power generating element 121. This configuration prevents peeling between the power generating elements. [Example]

[0140] The present embodiment will be described below using examples, but the present embodiment is not limited to these.

[0141] <Production of battery components> Example 1 The following materials were prepared:

[0142] First component: Aluminum foil (thickness: 50 μm) Second component: Cu foil (thickness: 8.0 μm) Main ingredient: Aronmelt PPET series (manufactured by Toagosei Co., Ltd.) Hardener: Aron Mighty PU series (manufactured by Toagosei Co., Ltd.) Conductive material: Ni-plated particles Porous particles: zeolite Solvent: methylcyclohexane, methyl ethyl ketone A slurry was prepared by mixing 150 parts by mass of the base agent, 15 parts by mass of the curing agent, 0.8 parts by mass of Ni-plated particles, 180 parts by mass of zeolite, and 850 parts by mass of the solvent.

[0143] Next, using the apparatus shown in Figure 3, Al foil and Cu foil were bonded via an adhesive layer. Specifically, Al foil was set in a coating device equipped with two gravure rolls, and slurry was applied to the Al foil. The slurry applied to the Al foil was dried in a drying oven to form an adhesive layer. Then, Cu foil was set on the side of the adhesive layer opposite to the side where the Al foil was attached, and pressed with two heated rolls to produce a battery component in which Al foil, adhesive layer, and Cu foil were laminated in this order. The conditions for the apparatus shown in Figure 3 are as follows. The adhesive layer was formed on the entire surface contacting the Al foil and the surface contacting the Cu foil.

[0144] [conditions] Speed: 15m / min Gravure roll: elongated, 75 lines Drying oven temperature: 150℃ Heat roll temperature: 95℃ Heat roll pressure: 0.45 MPa (Comparative Example 1) A battery component was produced in the same manner as in Example 1, except that zeolite was not used.

[0145] <Evaluation> (bubbles) The battery components of Example 1 and Comparative Example 1 were placed on a hot plate and heated for 10 minutes at 110° C. Thereafter, the surfaces of the Cu foils of the battery components of Example 1 and Comparative Example 1 were visually observed to check for the presence or absence of bubbles.

[0146] (peel strength) A 180-degree peel test was performed on the battery components of Example 1 and Comparative Example 1. Specifically, each battery component was cut into a 15 mm width so that the edges had portions uncoated with adhesive, and the Al foil and Cu foil in the uncoated portions were gripped and measured using an autograph (manufactured by Shimadzu Corporation). The pulling speed was 150 mm / min, and the strength at which the stress in the test profile became constant was taken as the peel strength.

[0147] <Result> Fig. 9 is a photograph of the appearance of the battery component in Example 1 after heating, and Fig. 10 is a photograph of the appearance of the battery component in Comparative Example 1 after heating. No bubbles were observed on the surface in Example 1. On the other hand, in Comparative Example 1, it was confirmed that numerous bubbles had formed on the surface.

[0148] Furthermore, when the peel strength of Example 1 in the 180-degree peel test was taken as 1, the relative value of the peel strength of Comparative Example 1 was 0.81.

[0149] From the above, it was found that the inclusion of porous particles in the adhesive layer could suppress the generation of bubbles and also the peeling of the battery components.

[0150] The embodiments and examples disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0151] 1 first member, 2 second member, 3 adhesive layer, 4 adhesive, 5 conductive additive, 6 porous particles, 10 battery member, 11 gravure roll, 12 hot air drying furnace, 13 heated roll, 15 battery member manufacturing apparatus, 20 positive electrode, 21 positive electrode current collector, 22 positive electrode active material layer, 23 adhesive layer, 30 negative electrode, 31 negative electrode current collector, 32 negative electrode active material layer, 33 adhesive layer, 40 separator, 50 power generating element, 100 lithium ion secondary battery, 111 adhesive layer, 112 positive electrode current collector, 113 positive electrode active material layer, 114 negative electrode current collector, 115 negative electrode active material layer, 116 separator, 120, 121 power generating element, 130 bipolar battery.

Claims

1. The adhesive sheet includes a first member, an adhesive layer, and a second member in this order, the adhesive layer includes an adhesive, a conductive additive, and porous particles; The adhesive includes a base agent and a curing agent, A battery component comprising, relative to 100 parts by mass of the main agent, 5.0 parts by mass or more and 10 parts by mass or less of the curing agent, 0.1 parts by mass or more and 1.0 parts by mass or less of the conductive additive, and 90 parts by mass or more and 200 parts by mass or less of the porous particles.

2. When the first member is a positive electrode current collector, the second member is a positive electrode active material layer or a negative electrode current collector, The battery member according to claim 1 , wherein when the first member is a negative electrode current collector, the second member is a positive electrode current collector or a negative electrode active material layer.

3. the first member and the second member are current collectors, The battery member according to claim 1 , wherein the adhesive layer bonds surfaces of the first member and the second member that face each other in a thickness direction of the stacked members.

4. A bipolar battery comprising the battery component of claim 3.

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