Cathode materials and batteries

Abstract

A positive electrode material 1000 according to the present disclosure contains a positive electrode active material 110 and a first solid electrolyte material 111 that covers at least a part of the surface of the positive electrode active material 110. Meanwhile, the first solid electrolyte material 111 contains Li, Ti, M1 and F; and M1 is at least one element that is selected from the group consisting of Ca, Mg, Al, Y and Zr.

Description

[Technical Field]

[0001] The present disclosure relates to positive electrode materials and batteries. [Background technology]

[0002] Patent Document 1 discloses a battery using a compound containing indium as a cation and a halogen element as an anion as a solid electrolyte. Patent Document 1 discloses that chlorine, bromine, and iodine are used as the halogen elements contained in the solid electrolyte, and that chlorine and bromine are particularly preferably used. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-244734 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a positive electrode material that can suppress an increase in the internal resistance of a battery during charging. [Means for solving the problem]

[0005] The positive electrode material of the present disclosure comprises: a positive electrode active material, and a first solid electrolyte material that covers at least a portion of the surface of the positive electrode active material; Including, where: the first solid electrolyte material comprises Li, Ti, M1, and F; The M1 is at least one element selected from the group consisting of Ca, Mg, Al, Y, and Zr. [Effects of the Invention]

[0006] The present disclosure provides a positive electrode material that can suppress an increase in the internal resistance of a battery during charging. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a positive electrode material 1000 according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a schematic configuration of a positive electrode material 1000 including a second electrolyte material 100 according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing a schematic configuration of a battery 2000 according to the second embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a schematic configuration of a battery 3000 according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (Findings that formed the basis of this disclosure) Patent Document 1 discloses an all-solid-state secondary battery including a solid electrolyte made of a compound containing indium as a cation and a halogen element as an anion. Patent Document 1 mentions that in this all-solid-state secondary battery, it is desirable that the potential of the positive electrode active material against Li is 3.9 V or less on average, which suppresses the formation of a film made of decomposition products due to oxidative decomposition of the solid electrolyte, thereby obtaining good charge-discharge characteristics. Furthermore, as a positive electrode active material having an average potential against Li of 3.9 V or less, LiCoO2 or LiNi 0.8 Co 0.15 Al 0.05 Common layered transition metal oxides such as O2 are disclosed.

[0009] The present inventors have investigated the resistance of halide solid electrolytes to oxidative decomposition. Halide solid electrolytes are materials containing halogen elements such as fluorine (i.e., F), chlorine (i.e., Cl), bromine (i.e., Br), and iodine (i.e., I) as anions. As a result of their investigation, they have found that the resistance of halide solid electrolytes to oxidative decomposition varies depending on the type of element contained as anion.

[0010] Specifically, we found that in batteries using a halide solid electrolyte containing at least one element selected from the group consisting of chlorine, bromine, and iodine as the positive electrode material, the halide solid electrolyte undergoes oxidative decomposition during charging, even when the positive electrode active material has an average potential vs. Li of 3.9 V or less. We also discovered that the oxidative decomposition product acts as a resistive layer, resulting in an increase in the battery's internal resistance during charging. We speculate that this is due to the oxidation reaction of an element selected from the group consisting of chlorine, bromine, and iodine contained in the halide solid electrolyte. Here, the oxidation reaction refers to not only the normal charging reaction in which lithium and electrons are extracted from the positive electrode active material in the positive electrode material, but also a side reaction in which electrons are extracted from the halide solid electrolyte containing at least one element selected from the group consisting of chlorine, bromine, and iodine that is in contact with the positive electrode active material. This oxidation reaction forms an oxidative decomposition layer with poor lithium ion conductivity between the positive electrode active material and the halide solid electrolyte, and this oxidative decomposition layer is thought to act as a significant interfacial resistance in the positive electrode reaction. Chlorine, bromine, and iodine are thought to be easily oxidized because they have a relatively large ionic radius and have a small interaction force with the cationic components that make up the halide solid electrolyte.

[0011] The present inventors have conducted extensive research into ways to suppress an increase in the internal resistance of a battery during charging, and have found that when a positive electrode material includes a positive electrode active material and a solid electrolyte material that coats at least a portion of the positive electrode active material, and the solid electrolyte material is a halide solid electrolyte containing fluorine, the positive electrode material exhibits excellent oxidation resistance and can suppress an increase in the internal resistance of a battery using the positive electrode material during charging. Although the details of this mechanism are not clear, the inventors speculate that when the halide solid electrolyte contains fluorine, which has a high electronegativity among halogen elements, as an anion, the fluorine bonds strongly with the cation, making it difficult for the oxidation reaction of fluorine, i.e., a side reaction in which electrons are extracted from fluorine, to proceed.

[0012] Furthermore, it has been found that when the fluorine-containing halide solid electrolyte contains lithium (i.e., Li), titanium (i.e., Ti), and M1, where M1 is at least one element selected from the group consisting of calcium (i.e., Ca), magnesium (i.e., Mg), aluminum (i.e., Al), yttrium (i.e., Y), and zirconium (i.e., Zr), the fluorine-containing halide solid electrolyte has high lithium ion conductivity and high oxidation resistance.

[0013] Based on the above findings, a positive electrode material comprising a positive electrode active material and a solid electrolyte material coating at least a portion of the surface of the positive electrode active material, the solid electrolyte material containing Li, Ti, M1, and F, where M1 is at least one element selected from the group consisting of Ca, Mg, Al, Y, and Zr, has high oxidation resistance and can suppress an increase in internal resistance during battery charging. Furthermore, because the solid electrolyte material has high ionic conductivity, it can reduce the interfacial resistance between the positive electrode active material and the solid electrolyte material, thereby improving the output characteristics of the battery.

[0014] (Summary of one aspect of the present disclosure) The positive electrode material according to the first aspect of the present disclosure is a positive electrode active material, and A first solid electrolyte material that coats at least a part of the surface of the positive electrode active material comprising where the first solid electrolyte material contains Li, Ti, M1, and F where M1 is at least one element selected from the group consisting of Ca, Mg, Al, Y, and Zr.

[0015] The positive electrode material according to the first aspect has high oxidation resistance. Therefore, the positive electrode material according to the first aspect can suppress an increase in the internal resistance of the battery during charging. Further, the first solid electrolyte material has high ionic conductivity. Therefore, in the positive electrode material, a low interfacial resistance between the first solid electrolyte material and the positive electrode active material can be realized. Therefore, the positive electrode material according to the first aspect can improve the output characteristics of the battery.

[0016] In the second aspect of the present disclosure, for example, in the positive electrode material according to the first aspect, M1 may be at least one element selected from the group consisting of Mg and Ca.

[0017] In the positive electrode material according to the second aspect, the first solid electrolyte material exhibits higher ionic conductivity. Therefore, in the positive electrode material, a lower interfacial resistance between the first solid electrolyte material and the positive electrode active material can be realized.

[0018] In the third aspect of the present disclosure, for example, in the positive electrode material according to the first or second aspect, the first solid electrolyte material may contain a material represented by the following compositional formula (1). Li 6-(4-2x1)b1 (Ti 1-x1 M1 x1 ) b1 F6 ··· Formula (1) Here, 0 <x1 <1 and 0 <b1 ≤ 3 are satisfied.

[0019] In the positive electrode material according to the third aspect, the first solid electrolyte material exhibits higher ionic conductivity, which allows the positive electrode material to achieve lower interfacial resistance between the first solid electrolyte material and the positive electrode active material.

[0020] In a fourth aspect of the present disclosure, for example, in the positive electrode material according to the third aspect, the first solid electrolyte material is Li3Ti 0.5 Mg 0.5 May contain F6.

[0021] In the positive electrode material according to the fourth aspect, the first solid electrolyte material exhibits higher ionic conductivity, which allows the positive electrode material to achieve lower interfacial resistance between the first solid electrolyte material and the positive electrode active material.

[0022] In a fifth aspect of the present disclosure, for example, in the positive electrode material according to the third aspect, the first solid electrolyte material is Li3Ti 0.5 Ca 0.5 May contain F6.

[0023] In the positive electrode material according to the fifth aspect, the first solid electrolyte material exhibits higher ionic conductivity, which allows the positive electrode material to achieve lower interfacial resistance between the first solid electrolyte material and the positive electrode active material.

[0024] In a sixth aspect of the present disclosure, for example, in the positive electrode material according to the first aspect, M1 may contain at least one element selected from the group consisting of Al and Y.

[0025] In the positive electrode material according to the sixth aspect, the first solid electrolyte material exhibits higher ionic conductivity, which allows the positive electrode material to achieve lower interfacial resistance between the first solid electrolyte material and the positive electrode active material.

[0026] In a seventh aspect of the present disclosure, for example, in the positive electrode material according to the first or sixth aspect, the first solid electrolyte material may include a material represented by the following composition formula (2): Li 6-(4-x2)b2(Ti 1-x2 M1 x2 ) b2 F6···Formula (2) Here, 0 < x2 < 1 and 0 < b2 ≤ 1.5 are satisfied.

[0027] In the positive electrode material according to the seventh aspect, the first solid electrolyte material exhibits higher ionic conductivity. Therefore, in the positive electrode material, a lower interfacial resistance between the first solid electrolyte material and the positive electrode active material can be realized.

[0028] In the eighth aspect of the present disclosure, for example, in the positive electrode material according to the seventh aspect, the first solid electrolyte material may contain Li 2.6 Ti 0.4 Al 0.6 F6.

[0029] In the positive electrode material according to the eighth aspect, the first solid electrolyte material exhibits higher ionic conductivity. Therefore, in the positive electrode material, a lower interfacial resistance between the first solid electrolyte material and the positive electrode active material can be realized.

[0030] In the ninth aspect of the present disclosure, for example, in the positive electrode material according to the first aspect, M1 may contain Zr.

[0031] In the positive electrode material according to the ninth aspect, the first solid electrolyte material exhibits higher ionic conductivity. Therefore, in the positive electrode material, a lower interfacial resistance between the first solid electrolyte material and the positive electrode active material can be realized.

[0032] In the tenth aspect of the present disclosure, for example, in the positive electrode material according to the ninth aspect, the solid electrolyte material may contain a material represented by the following compositional formula (3). Li 6-4b3 (Ti 1-x3 Zr x3 ) b3 F6···Formula (3) Here, 0 < x3 < 1 and 0 < b3 ≤ 1.5 are satisfied.

[0033] In the positive electrode material according to the tenth aspect, the first solid electrolyte material exhibits higher ionic conductivity, which allows the positive electrode material to achieve lower interfacial resistance between the first solid electrolyte material and the positive electrode active material.

[0034] In an eleventh aspect of the present disclosure, for example, in the positive electrode material according to the tenth aspect, the first solid electrolyte material is Li3Ti 0.5 Zr 0.5 May include F7.

[0035] In the positive electrode material according to the eleventh aspect, the first solid electrolyte material exhibits higher ionic conductivity, which allows the positive electrode material to achieve lower interfacial resistance between the first solid electrolyte material and the positive electrode active material.

[0036] In a twelfth aspect of the present disclosure, for example, in the positive electrode material according to the first aspect, the M1 may include Al and at least one element selected from the group consisting of Mg and Zr.

[0037] In the positive electrode material according to the twelfth aspect, the first solid electrolyte material exhibits higher ionic conductivity, which allows the positive electrode material to achieve lower interfacial resistance between the first solid electrolyte material and the positive electrode active material.

[0038] In a thirteenth aspect of the present disclosure, for example, the positive electrode material according to any one of the first to twelfth aspects may further include a second electrolyte material that is a material different from the first solid electrolyte material.

[0039] In the positive electrode material according to the thirteenth aspect, the resistance resulting from the movement of Li ions in the positive electrode material can be reduced, and an increase in the internal resistance of the battery during charging can be more effectively suppressed.

[0040] In a fourteenth aspect of the present disclosure, for example, in the positive electrode material according to the thirteenth aspect, the second electrolyte material is represented by the following composition formula (5): Li α M2 β Xγ ...Equation (5) where: α, β, and γ are values ​​greater than 0, M2 includes at least one of a metal element other than Li and a metalloid element, X may be at least one element selected from the group consisting of F, Cl, Br, and I.

[0041] In the positive electrode material according to the fourteenth aspect, the ionic conductivity of the second electrolyte material can be further increased, thereby further reducing the resistance caused by the movement of Li ions in the positive electrode material and more effectively suppressing an increase in the internal resistance of the battery during charging.

[0042] In a fifteenth aspect of the present disclosure, for example, in the positive electrode material according to the fourteenth aspect, M2 may include Y.

[0043] In the positive electrode material according to the fifteenth aspect, the ionic conductivity of the second electrolyte material can be further increased, thereby further reducing the resistance caused by the movement of Li ions in the positive electrode material and more effectively suppressing an increase in the internal resistance of the battery during charging.

[0044] In a sixteenth aspect of the present disclosure, for example, in the positive electrode material according to the fourteenth or fifteenth aspect, the composition formula (5) is 2.5≦α≦3, 1≦β≦1.1, γ=6, may be satisfied.

[0045] In the positive electrode material according to the sixteenth aspect, the ionic conductivity of the second electrolyte material can be further increased, thereby further reducing the resistance caused by the movement of Li ions in the positive electrode material and more effectively suppressing an increase in the internal resistance of the battery during charging.

[0046] In a seventeenth aspect of the present disclosure, for example, in the positive electrode material according to the thirteenth aspect, the second electrolyte material may include a sulfide solid electrolyte.

[0047] In the positive electrode material according to the seventeenth aspect, the ionic conductivity of the second electrolyte material can be further increased, thereby further reducing the resistance caused by the movement of Li ions in the positive electrode material and more effectively suppressing an increase in the internal resistance of the battery during charging.

[0048] In an eighteenth aspect of the present disclosure, for example, in the positive electrode material according to the seventeenth aspect, the sulfide solid electrolyte may contain lithium sulfide and phosphorus sulfide.

[0049] In the positive electrode material according to the eighteenth aspect, the ionic conductivity of the second electrolyte material can be further increased, thereby further reducing the resistance caused by the movement of Li ions in the positive electrode material and more effectively suppressing an increase in the internal resistance of the battery during charging.

[0050] In a nineteenth aspect of the present disclosure, for example, in the positive electrode material according to the seventeenth or eighteenth aspect, the sulfide solid electrolyte may be Li2S-P2S5.

[0051] In the positive electrode material according to the nineteenth aspect, the ionic conductivity of the second electrolyte material can be further increased, thereby further reducing the resistance caused by the movement of Li ions in the positive electrode material and more effectively suppressing an increase in the internal resistance of the battery during charging.

[0052] In a twentieth aspect of the present disclosure, for example, in the positive electrode material according to the thirteenth aspect, the second electrolyte material may be an electrolyte solution containing a lithium salt and a solvent.

[0053] The positive electrode material according to the twentieth aspect can suppress an increase in the internal resistance of the battery during charging.

[0054] In a twenty-first aspect of the present disclosure, for example, in the positive electrode material according to any one of the first to twentieth aspects, the positive electrode active material may include lithium nickel-cobalt-manganese oxide.

[0055] The positive electrode material according to the twenty-first embodiment can further increase the energy density and charge / discharge efficiency of the battery.

[0056] In a 22nd aspect of the present disclosure, for example, in the positive electrode material according to the 13th aspect, the first solid electrolyte material may be provided between the positive electrode active material and the second electrolyte material.

[0057] In the positive electrode material according to the twenty-second aspect, the first solid electrolyte material, which has high oxidation resistance, is interposed between the positive electrode active material and the second electrolyte material, thereby suppressing oxidative decomposition of the second electrolyte material and suppressing an increase in the internal resistance of the battery during charging.

[0058] A battery according to a twenty-third aspect of the present disclosure comprises: a positive electrode comprising the positive electrode material according to any one of the first to twenty-second aspects; a negative electrode, and an electrolyte layer disposed between the positive electrode and the negative electrode; Equipped with.

[0059] In the battery according to the twenty-third aspect, an increase in the internal resistance of the battery during charging can be suppressed.

[0060] In a 24th aspect of the present disclosure, for example, in the battery according to the 23rd aspect, the positive electrode material may further include a second electrolyte material that is a material different from the first solid electrolyte material, and the electrolyte layer may include the same material as the first solid electrolyte material or the second electrolyte material.

[0061] In the battery according to the twenty-fourth embodiment, the power density and charge / discharge characteristics are further improved.

[0062] In a 25th aspect of the present disclosure, for example, in the battery according to the 24th aspect, the electrolyte layer may contain the same material as the first solid electrolyte material.

[0063] In the battery according to the twenty-fifth aspect, an increase in the internal resistance of the battery during charging, which is caused by oxidation of the electrolyte layer, is suppressed, and the power density and charge / discharge characteristics are further improved.

[0064] In a 26th aspect of the present disclosure, for example, in the battery according to the 23rd or 24th aspect, the electrolyte layer includes a first electrolyte layer and a second electrolyte layer, The first electrolyte layer may be in contact with the positive electrode, and the second electrolyte layer may be in contact with the negative electrode.

[0065] The battery according to the twenty-sixth aspect can suppress an increase in the internal resistance of the battery during charging.

[0066] In a 27th aspect of the present disclosure, for example, in the battery according to the 26th aspect, the first electrolyte layer may contain the same material as the first solid electrolyte material.

[0067] In the battery according to the twenty-seventh embodiment, the first electrolyte layer contains the first solid electrolyte material, which has excellent oxidation resistance, thereby suppressing oxidative decomposition of the first electrolyte layer and thus suppressing an increase in the internal resistance of the battery during charging.

[0068] In a 28th aspect of the present disclosure, for example, in the battery according to the 26th or 27th aspect, the second electrolyte layer may contain a material different from the first solid electrolyte material.

[0069] In the battery according to the 28th embodiment, the charge and discharge characteristics are further improved.

[0070] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0071] (Embodiment 1) Fig. 1 is a cross-sectional view showing a schematic configuration of a cathode material 1000 according to the first embodiment. As shown in Fig. 1, the cathode material 1000 according to the first embodiment includes a cathode active material 110 and a first solid electrolyte material 111 that coats at least a portion of the surface of the cathode active material 110. Here, the first solid electrolyte material 111 includes Li, Ti, M1, and F, and M1 is at least one element selected from the group consisting of Ca, Mg, Al, Y, and Zr.

[0072] According to the above configuration, the positive electrode material 1000 has high oxidation resistance. Therefore, the positive electrode material 1000 can suppress an increase in the internal resistance of the battery during charging. Furthermore, the first solid electrolyte material 111 has high ionic conductivity. Therefore, in the positive electrode material 1000, low interfacial resistance between the first solid electrolyte material 111 and the positive electrode active material 110 can be achieved.

[0073] M1 may be at least one element selected from the group consisting of Ca and Mg.

[0074] According to the above configuration, the first solid electrolyte material 111 exhibits higher ionic conductivity, and therefore, in the positive electrode material 1000, low interface resistance between the first solid electrolyte material 111 and the positive electrode active material 110 can be achieved.

[0075] When M1 is at least one element selected from the group consisting of Ca and Mg, the ratio of the amount of substance of Li to the total amount of substance of Ca, Mg, and Ti may be 0.5 or more and 4.5 or less.

[0076] When M1 is at least one element selected from the group consisting of Ca and Mg, the first solid electrolyte material 111 may contain a material represented by the following composition formula (1): The material represented by the following composition formula (1) may be in a crystalline phase.

[0077] Li 6-(4-2x1)b (Ti 1-x1 M1 x1 ) b1 F6...Formula (1) Here, 0 < x1 < 1 and 0 < b1 ≤ 3 are satisfied.

[0078] In compositional formula (1), 0.05 ≤ x1 ≤ 0.9 may be satisfied.

[0079] In compositional formula (1), M1 is Mg and 0.05 ≤ x1 ≤ 0.6 may be satisfied.

[0080] In compositional formula (1), M1 is Ca and x1 = 0.5 may be satisfied.

[0081] In compositional formula (1), 0.80 ≤ b1 ≤ 1.71 may be satisfied.

[0082] According to the above configuration, the first solid electrolyte material 111 exhibits a higher ionic conductivity.

[0083] The first solid electrolyte material 111 may contain Li₃Ti 0.5 Mg 0.5 F₆.

[0084] According to the above configuration, the first solid electrolyte material 111 exhibits a higher ionic conductivity. Therefore, in the positive electrode material 1000, a low interfacial resistance between the first solid electrolyte material 111 and the positive electrode active material 110 can be realized.

[0085] The first solid electrolyte material 111 may contain Li₃Ti 0.5 Ca 0.5 F₆. <​​​​​​​​​​According to the above configuration, the first solid electrolyte material 111 exhibits a higher ionic conductivity. Therefore, in the positive electrode material 1000, a low interfacial resistance between the first solid electrolyte material 111 and the positive electrode active material 110 can be achieved.

[0089] When M1 is at least one element selected from the group consisting of Al and Y, the ratio of the amount of substance of Li to the total amount of substances of Al, Y, and Ti may be 1.7 or more and 4.2 or less.

[0090] When M1 is at least one element selected from the group consisting of Al and Y, the first solid electrolyte material 111 may contain a material represented by the following composition formula (2). The material represented by the composition formula (2) may be a crystal phase.

[0091] Li 6-(4-x2)b2 (Ti 1-x2 M1 x2 ) b2 F6 ··· Formula (2) Here, 0 < x2 < 1 and 0 < b2 ≤ 1.5 are satisfied.

[0092] In the composition formula (2), M1 may be Al.

[0093] In the composition formula (2), 0.1 ≤ x2 ≤ 0.9 may be satisfied.

[0094] In the composition formula (2), M1 is Y, and 0.3 ≤ x2 ≤ 0.7 may be satisfied.

[0095] In the composition formula (2), 0.8 ≤ b2 ≤ 1.2 may be satisfied.

[0096] According to the above configuration, the first solid electrolyte material 111 exhibits a higher ionic conductivity.

[0097] The first solid electrolyte material 111 may contain Li 2.6 Ti 0.4 Al 0.6 F6.

[0098] According to the above configuration, the first solid electrolyte material 111 exhibits a higher ionic conductivity. Therefore, in the positive electrode material 1000, a low interfacial resistance between the first solid electrolyte material 111 and the positive electrode active material 110 can be achieved.

[0099] M1 may contain Zr.

[0100] According to the above configuration, the first solid electrolyte material 111 exhibits a higher ionic conductivity. Therefore, in the positive electrode material 1000, a low interfacial resistance between the first solid electrolyte material 111 and the positive electrode active material 110 can be achieved.

[0101] When M1 is Zr, the ratio of the amount of substance of Li to the total amount of substances of Ti and Zr may be 2.0 or more and 6.0 or less.

[0102] When M1 is Zr, the first solid electrolyte material 111 may contain a material represented by the following compositional formula (3). The material represented by the compositional formula (3) may be a crystal phase.

[0103] Li 6-4b3 (Ti 1-x3 Zr x3 ) b3 F6 ··· Formula (3) Here, 0 < x3 < 1 and 0 < b < 3 ≦ 1.5 are satisfied.

[0104] In the compositional formula (3), 0.1 ≦ x3 ≦ 0.8 may be satisfied.

[0105] In the compositional formula (3), 0.6 ≦ b3 ≦ 1.0 may be satisfied.

[0106] According to the above configuration, the first solid electrolyte material 111 exhibits a higher ionic conductivity.

[0107] The first solid electrolyte material 111 may contain Li3Ti 0.5 Zr 0.5 F7.

[0108] According to the above configuration, the first solid electrolyte material 111 exhibits a higher ionic conductivity. Therefore, in the positive electrode material 1000, a low interfacial resistance between the first solid electrolyte material 111 and the positive electrode active material 110 can be realized.

[0109] M1 may contain Al and at least one element selected from the group consisting of Mg and Zr.

[0110] According to the above configuration, the first solid electrolyte material 111 exhibits a higher ionic conductivity. Therefore, in the positive electrode material 1000, a low interfacial resistance between the first solid electrolyte material 111 and the positive electrode active material 110 can be realized.

[0111] When M1 contains Al and at least one element selected from the group consisting of Mg and Zr, the ratio of the amount of substance of Li to the total amount of substances of Zr, Mg, Ti, and Al may be 1.33 or more and 3.79 or less. [[ID=1,6]]

[0112] When M1 contains Al and at least one element selected from the group consisting of Mg and Zr, the first solid electrolyte material 111 may contain a material represented by the following compositional formula (4). The material represented by the compositional formula (4) may be a crystal phase.

[0113] Li 6-(4-x4-(4-m)y)b4 (Ti 1-x4-y Al x4 M1 y ) b4 F6 ··· Formula (4) Here, m represents the valence of M1, 0 < x4 < 1, 0 < y < 1, 0 < (x4 + y) < 1, and 0 < b4 ≤ 1.5 are satisfied.

[0114] In the compositional formula (4), 0.05 ≤ x4 ≤ 0.9 may be satisfied. <0,000533> In the compositional formula (4), 0.05 ≤ y ≤ 0.9 may be satisfied.

[0116] In composition formula (4), M1 may be Mg, and 0.33≦x4≦0.7 may be satisfied.

[0117] In the composition formula (4), M1 may be Mg, and 0.1≦y≦0.33 may be satisfied.

[0118] In the composition formula (4), 0.8≦b4≦1.2 may be satisfied.

[0119] According to the above configuration, the first solid electrolyte material 111 exhibits higher ionic conductivity.

[0120] In order to further increase the ionic conductivity of the first solid electrolyte material 111, the first solid electrolyte material 111 may contain an element other than F as an anion. Examples of the element contained as the anion include Cl, Br, I, O, S, and Se.

[0121] 2, the positive electrode material 1000 in the first embodiment may further include a second electrolyte material 100 that is a material different from the first solid electrolyte material 111. Here, the second electrolyte material 100 being different from the first solid electrolyte material 111 means, for example, that the second electrolyte material 100 has a different composition from the first solid electrolyte material 111, or that the second electrolyte material 100 has a different form from the first solid electrolyte material 111, such as an electrolytic solution.

[0122] By including the second electrolyte material 100, the resistance resulting from the movement of Li ions in the positive electrode material 1000 can be reduced.

[0123] The second electrolyte material 100 may be a material represented by the following composition formula (5): Li α M2 β X γ ...Equation (5) Here, α, β, and γ are values ​​greater than 0, M2 includes at least one of a metal element other than Li and a metalloid element, and X is at least one element selected from the group consisting of F, Cl, Br, and I.

[0124] The above configuration can further increase the ionic conductivity of the second electrolyte material 100. This can further reduce the resistance caused by the movement of Li ions in the positive electrode material 1000.

[0125] "Semi-metallic elements" are B, Si, Ge, As, Sb, and Te.

[0126] "Metal elements" are all elements in groups 1 to 12 of the periodic table except hydrogen, and all elements in groups 13 to 16 except B, Si, Ge, As, Sb, Te, C, N, P, O, S, and Se. In other words, this is a group of elements that can become cations when forming inorganic compounds with halogen compounds.

[0127] In the second electrolyte material 100, M2 may contain Y. That is, the second electrolyte material 100 may contain Y as a metal element.

[0128] The above configuration can further increase the ionic conductivity of the second electrolyte material 100. This can further reduce the resistance caused by the movement of Li ions in the positive electrode material 1000.

[0129] In the composition formula (5), 0<α<6, 0<β<3, and γ=6 may be satisfied. In the composition formula (5), 2.5≦α≦3, 1≦β≦1.1, and γ=6 may be satisfied.

[0130] The above configuration can further increase the ionic conductivity of the second electrolyte material 100. This can further reduce the resistance caused by the movement of Li ions in the positive electrode material 1000.

[0131] The second electrolyte material 100 containing Y may be, for example, Li a1 Me b5 Y cIt may also be a compound represented by the composition formula of X6. Here, a1 + m'b5 + 3c = 6 and c > 0 are satisfied. Me is at least one element selected from the group consisting of metal elements and semi-metal elements excluding Li and Y. Also, m' is the valence of Me.

[0132] As Me, at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Zn, Sc, Al, Ga, Bi, Zr, Hf, Ti, Sn, Ta, and Nb may be used.

[0133] According to the above configuration, the ionic conductivity of the second electrolyte material 100 can be further increased. Thereby, the resistance resulting from the movement of Li ions in the positive electrode material 1000 can be further reduced.

[0134] The second electrolyte material 100 may be a material represented by the following composition formula (A1). Li 6-3d Y d X6 ··· Formula (A1) Here, in the composition formula (A1), X is a halogen element and contains Cl. Also, 0 < d < 2 is satisfied.

[0135] According to the above configuration, the ionic conductivity of the second electrolyte material 100 can be further increased. Thereby, the resistance resulting from the movement of Li ions in the positive electrode material 1000 can be further reduced.

[0136] The second electrolyte material 100 may be a material represented by the following composition formula (A2). Li3YX6 ··· Formula (A2) Here, in the composition formula (A2), X is a halogen element and contains Cl.

[0137] According to the above configuration, the ionic conductivity of the second electrolyte material 100 can be further increased. Thereby, the resistance resulting from the movement of Li ions in the positive electrode material 1000 can be further reduced.

[0138] The second electrolyte material 100 may be a material represented by the following compositional formula (A3). Li 3-3δ1 Y 1+δ1 Cl6··· Formula (A3) Here, in the compositional formula (A3), 0 < δ1 ≤ 0.15 is satisfied.

[0139] According to the above configuration, the ionic conductivity of the second electrolyte material 100 can be further increased. Thereby, the resistance resulting from the movement of Li ions in the positive electrode material 1000 can be further reduced.

[0140] The second electrolyte material 100 may be a material represented by the following compositional formula (A4). Li 3-3δ2+a2 Y 1+δ2-a2 [[ID=2​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0143] According to the above configuration, the ionic conductivity of the second electrolyte material 100 can be further increased. As a result, the resistance resulting from the movement of Li ions in the positive electrode material 1000 can be further reduced.

[0144] The second electrolyte material 100 may be a material represented by the following compositional formula (A6). Li 3-3δ4-a4 Y 1+δ4-a4 Me a4 Cl 6-x7 Br x7 ··· Formula (A6) Here, in the compositional formula (A6), Me is at least one element selected from the group consisting of Zr, Hf, and Ti. Also, -1 < δ4 < 1, 0 < a4 < 1.5, 0 < (3 - 3δ4 - a4), 0 < (1 + δ4 - a4), and 0 ≤ x7 < 6 are satisfied.

[0145] According to the above configuration, the ionic conductivity of the second electrolyte material 100 can be further increased. As a result, the resistance resulting from the movement of Li ions in the positive electrode material 1000 can be further reduced.

[0146] The second electrolyte material 100 may be a material represented by the following compositional formula (A7). Li 3-3δ5-2a5 Y 1+δ5-a5 Me a5 Cl 6-x8 Br x8 ··· Formula (A7) Here, in the compositional formula (A7), Me is at least one element selected from the group consisting of Ta and Nb. Also, -1 < δ5 < 1, 0 < a5 < 1.2, 0 < (3 - 3δ5 - 2a5), 0 < (1 + δ5 - a5), and 0 ≤ x8 < 6 are satisfied.

[0147] According to the above configuration, the ionic conductivity of the second electrolyte material 100 can be further increased. As a result, the resistance resulting from the movement of Li ions in the positive electrode material 1000 can be further reduced.

[0148] Examples of the second electrolyte material 100 that can be used include Li3YX6, Li2MgX4, Li2FeX4, Li(Al, Ga, In)X4, and Li3(Al, Ga, In)X6. Here, X includes Cl. In this disclosure, when an element in a formula is expressed as "(Al, Ga, In)," this notation indicates at least one element selected from the group of elements in parentheses. In other words, "(Al, Ga, In)" is synonymous with "at least one element selected from the group consisting of Al, Ga, and In." The same applies to other elements. The second electrolyte material 100 does not necessarily need to contain sulfur.

[0149] The second electrolyte material 100 may include a sulfide solid electrolyte. Examples of sulfide solid electrolytes include Li2S-P2S5, Li2S-SiS2, Li2S-B2S3, Li2S-GeS2, and Li 3.25 Ge 0.25 P 0.75 S4, Li 10 GeP2S 12 , etc. can be used. In addition to these, LiX, Li2O, MO q , Li p MO q , etc. may be added. Here, X is at least one element selected from the group consisting of F, Cl, Br, and I. Furthermore, M is at least one element selected from the group consisting of P, Si, Ge, B, Al, Ga, In, Fe, and Zn. Furthermore, p and q are each independently a natural number.

[0150] The above configuration can further increase the ionic conductivity of the second electrolyte material 100. This can further reduce the resistance caused by the movement of Li ions in the positive electrode material 1000.

[0151] The second electrolyte material 100 may include lithium sulfide and phosphorus sulfide. For example, the sulfide solid electrolyte may be Li2S-P2S5.

[0152] The above configuration can further increase the ionic conductivity of the second electrolyte material 100. This can further reduce the resistance caused by the movement of Li ions in the positive electrode material 1000.

[0153] The second electrolyte material 100 may include an electrolyte solution.

[0154] The electrolyte contains water or a non-aqueous solvent and a lithium salt dissolved in the solvent.

[0155] Examples of the solvent include water, a cyclic carbonate solvent, a chain carbonate solvent, a cyclic ether solvent, a chain ether solvent, a cyclic ester solvent, a chain ester solvent, a fluorine-containing solvent, and the like.

[0156] Examples of cyclic carbonate solvents include ethylene carbonate, propylene carbonate, and butylene carbonate.

[0157] Examples of the chain carbonate ester solvent include dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate.

[0158] Examples of cyclic ether solvents are tetrahydrofuran, 1,4-dioxane, or 1,3-dioxolane, and the like.

[0159] Examples of chain ether solvents are 1,2-dimethoxyethane, 1,2-diethoxyethane, and the like.

[0160] Examples of cyclic ester solvents include γ-butyrolactone, and the like.

[0161] An example of a chain ester solvent is methyl acetate, and the like.

[0162] Examples of fluorine-containing solvents include fluoroethylene carbonate, methyl fluoropropionate, fluorobenzene, fluoroethyl methyl carbonate, and fluorodimethylene carbonate.

[0163] As the solvent, one solvent selected from these may be used alone, or a combination of two or more solvents selected from these may be used.

[0164] The electrolytic solution may contain at least one fluorine solvent selected from the group consisting of fluoroethylene carbonate, methyl fluoropropionate, fluorobenzene, fluoroethyl methyl carbonate, and fluorodimethylene carbonate.

[0165] Examples of lithium salts that can be used include LiPF, LiBF, LiSbF, LiAsF, LiSOCF, LiN(SOCF), LiN(SOCF) , LiN(SOCF)(SOCF), and LiC(SOCF). A single lithium salt selected from these can be used. Alternatively, a mixture of two or more lithium salts selected from these can be used. The concentration of the lithium salt is, for example, in the range of 0.1 to 15 mol / L.

[0166] The positive electrode active material 110 includes a material capable of absorbing and releasing metal ions (e.g., lithium ions). Examples of the positive electrode active material 110 that can be used include lithium-containing transition metal oxides, transition metal fluorides, polyanion materials, fluorinated polyanion materials, transition metal sulfides, transition metal oxysulfides, and transition metal oxynitrides. Examples of lithium-containing transition metal oxides include Li(Ni,Co,Al)O2, Li(Ni,Co,Mn)O2, and LiCoO2. In particular, using a lithium-containing transition metal oxide as the positive electrode active material 110 can reduce the manufacturing cost of the positive electrode material 1000 and increase the average discharge voltage.

[0167] In the first embodiment, the positive electrode active material 110 may include lithium nickel-cobalt-manganese oxide. For example, the positive electrode active material 110 may include Li(Ni,Co,Mn)O 2 .

[0168] According to the above configuration, the energy density and charge / discharge efficiency of a battery using the positive electrode material 1000 can be further increased.

[0169] A first solid electrolyte material 111 may be provided between the positive electrode active material 110 and the second electrolyte material 100 .

[0170] According to the above configuration, the first solid electrolyte material 111, which has high oxidation resistance, is interposed between the positive electrode active material 110 and the second electrolyte material 100, thereby suppressing oxidative decomposition of the second electrolyte material 100. This makes it possible to suppress an increase in internal resistance during charging of a battery using the positive electrode material 1000.

[0171] The thickness of the first solid electrolyte material 111 covering at least a part of the surface of the positive electrode active material 110 may be 1 nm or more and 500 nm or less.

[0172] When the thickness of the first solid electrolyte material 111 is 1 nm or more, direct contact between the positive electrode active material 110 and the second electrolyte material 100 is suppressed, and oxidative decomposition of the second electrolyte material 100 can be suppressed. This improves the charge / discharge efficiency of a battery using the positive electrode material 1000. When the thickness of the first solid electrolyte material 111 is 500 nm or less, the thickness of the first solid electrolyte material 111 does not become too thick. This allows the internal resistance of a battery using the positive electrode material 1000 to be sufficiently reduced, and the energy density of the battery to be increased.

[0173] The method for measuring the thickness of the first solid electrolyte material 111 is not particularly limited, but for example, the thickness can be determined by directly observing the thickness of the first solid electrolyte material 111 using a transmission electron microscope or the like.

[0174] The mass ratio of the first solid electrolyte material 111 to the positive electrode active material 110 may be 0.01% or more and 30% or less.

[0175] When the mass ratio of the first solid electrolyte material 111 to the positive electrode active material 110 is 0.01% or more, direct contact between the positive electrode active material 110 and the second electrolyte material 100 is suppressed, and oxidative decomposition of the second electrolyte material 100 can be suppressed. This improves the charge / discharge efficiency of a battery using the positive electrode material 1000. When the mass ratio of the first solid electrolyte material 111 to the positive electrode active material 110 is 30% or less, the thickness of the first solid electrolyte material 111 does not become too thick. This allows the internal resistance of a battery using the positive electrode material 1000 to be sufficiently reduced, and the energy density of the battery to be increased.

[0176] The first solid electrolyte material 111 may uniformly cover the surface of the positive electrode active material 110. This prevents direct contact between the positive electrode active material 110 and the second electrolyte material 100, thereby suppressing side reactions of the second electrolyte material 100. This further improves the charge / discharge characteristics of a battery using the positive electrode material 1000, and also suppresses an increase in the internal resistance of the battery during charging.

[0177] The first solid electrolyte material 111 may cover a portion of the surface of the positive electrode active material 110. The plurality of positive electrode active materials 110 come into direct contact with each other through the portion not having the first solid electrolyte material 111, thereby improving the electronic conductivity between the plurality of positive electrode active materials 110. This enables a battery using the positive electrode material 1000 to operate at high power.

[0178] The first solid electrolyte material 111 may cover 30% or more, 60% or more, or 90% or more of the surface of the positive electrode active material 110. The first solid electrolyte material 111 may cover substantially the entire surface of the positive electrode active material 110.

[0179] At least a portion of the surface of the positive electrode active material 110 may be covered with a coating material different from the first solid electrolyte material 111.

[0180] Examples of the coating material include sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes. The sulfide solid electrolytes and halide solid electrolytes used in the coating material may be the same as those exemplified for the second electrolyte material 100. Examples of oxide solid electrolytes used in the coating material include Li-Nb-O compounds such as LiNbO3, Li-BO compounds such as LiBO2 and Li3BO3, Li-Al-O compounds such as LiAlO2, Li-Si-O compounds such as Li4SiO4, Li2SO4, Li4Ti5O 12 Li-Ti-O compounds such as Li2ZrO3, Li-Zr-O compounds such as Li2MoO3, Li-VO compounds such as LiV2O5, Li-WO compounds such as Li2WO4, and Li-PO compounds such as Li3PO4.

[0181] The above configuration can further improve the oxidation resistance of the positive electrode material 1000. This can suppress an increase in the internal resistance of the battery during charging.

[0182] The positive electrode active material 110 and the first solid electrolyte material 111 may be separated by a coating material and may not be in direct contact with each other.

[0183] The above configuration can further improve the oxidation resistance of the positive electrode material 1000. This can suppress an increase in the internal resistance of the battery during charging.

[0184] The shape of the second electrolyte material 100 in the first embodiment is not particularly limited. When the second electrolyte material 100 in the first embodiment is a powder material, its shape may be, for example, needle-like, spherical, oval-spherical, etc. For example, the shape of the second electrolyte material 100 may be particulate.

[0185] For example, when the second electrolyte material 100 in the first embodiment is in the form of particles (e.g., spheres), the median diameter of the second electrolyte material 100 may be 100 μm or less. When the median diameter of the second electrolyte material 100 is 100 μm or less, the positive electrode active material 110 and the second electrolyte material 100 can be well dispersed in the positive electrode material 1000. This improves the charge / discharge characteristics of a battery using the positive electrode material 1000.

[0186] In the first embodiment, the median diameter of the second electrolyte material 100 may be 10 μm or less. According to the above configuration, in the positive electrode material 1000, the positive electrode active material 110 and the second electrolyte material 100 can be well dispersed.

[0187] In the first embodiment, the median diameter of the second electrolyte material 100 may be smaller than the median diameter of the positive electrode active material 110. According to the above configuration, the second electrolyte material 100 and the positive electrode active material 110 can be better dispersed in the positive electrode.

[0188] The median diameter of the positive electrode active material 110 may be 0.1 μm or more and 100 μm or less.

[0189] When the median diameter of the positive electrode active material 110 is 0.1 μm or more, the positive electrode active material 110 and the second electrolyte material 100 can form a well-dispersed state in the positive electrode material 1000. This improves the charge / discharge characteristics of a battery using the positive electrode material 1000. When the median diameter of the positive electrode active material 110 is 100 μm or less, the lithium diffusion rate within the positive electrode active material 110 improves. This allows a battery using the positive electrode material 1000 to operate at high power.

[0190] The median diameter of the positive electrode active material 110 may be larger than the median diameter of the second electrolyte material 100. This allows the positive electrode active material 110 and the second electrolyte material 100 to form a well-dispersed state.

[0191] In the cathode material 1000 of the first embodiment, the second electrolyte material 100 and the first solid electrolyte material 111 may be in contact with each other, as shown in Fig. 2. In this case, the first solid electrolyte material 111 and the cathode active material 110 are in contact with each other.

[0192] The positive electrode material 1000 in the first embodiment may include a plurality of second electrolyte materials 100 and a plurality of positive electrode active materials 110.

[0193] In the positive electrode material 1000 of the first embodiment, the content of the second electrolyte material 100 and the content of the positive electrode active material 110 may be the same as or different from each other.

[0194] <Method for manufacturing first solid electrolyte material 111> The first solid electrolyte material 111 in the first embodiment can be produced, for example, by the following method.

[0195] Prepare raw material powders of binary halides with the desired composition ratio. For example, Li 2.7 Ti 0.3 Al 0.7 When producing F6, LiF, TiF4, and AlF3 are prepared in a molar ratio of approximately 2.7:0.3:0.7. Taking into account changes in composition during the synthesis process, the compounding ratio may be adjusted in advance to offset the changes.

[0196] After the raw material powders are thoroughly mixed, they are mixed, pulverized, and reacted by mechanochemical milling, and then may be fired in a vacuum or inert atmosphere.

[0197] Alternatively, the raw material powders may be thoroughly mixed and then fired in a vacuum or inert atmosphere. The firing conditions are preferably, for example, within a range of 100°C to 300°C for 1 hour or longer. Furthermore, in order to prevent changes in composition during the firing process, it is preferable to sinter the raw material powders in a sealed container such as a quartz tube.

[0198] As a result, the first solid electrolyte material 111 containing the composition described above is obtained.

[0199] <Method of manufacturing the positive electrode material 1000> The cathode material 1000 in the first embodiment can be manufactured, for example, by the following method. A cathode active material 110 and a first solid electrolyte material 111 are prepared in a predetermined mass ratio. For example, Li(Ni,Co,Mn)O2 is used as the cathode active material 110 and Li(Ni,Co,Mn)O2 is used as the first solid electrolyte material 111. 2.7 Ti 0.3 Al 0.7 These two materials are placed in the same reaction vessel, and a shear force is applied to the two materials using a rotating blade, or the two materials are collided with each other using a jet stream, thereby forming a first solid electrolyte material 111, Li, on at least a portion of the surface of the positive electrode active material Li(Ni,Co,Mn)O2. 2.7 Ti 0.3 Al 0.7 For example, a dry particle compounding device such as Nobilta (manufactured by Hosokawa Micron), a high-speed air current impact device (manufactured by Nara Machinery Works), or a jet mill can be used.

[0200] By the above method, at least a part of the surface of the positive electrode active material Li(Ni,Co,Mn)O2 is covered with the first solid electrolyte material 111, Li 2.7 Ti 0.3 Al 0.7 A cathode material 1000 coated with F6 can be produced.

[0201] (Embodiment 2) The following describes the second embodiment. Explanations that overlap with the first embodiment will be omitted where appropriate.

[0202] FIG. 3 is a cross-sectional view showing a schematic configuration of a battery 2000 according to the second embodiment. The battery 2000 in the second embodiment includes a positive electrode 201 , an electrolyte layer 202 , and a negative electrode 203 .

[0203] The positive electrode 201 includes the positive electrode material 1000 in the first embodiment.

[0204] The electrolyte layer 202 is disposed between the positive electrode 201 and the negative electrode 203 .

[0205] According to the above configuration, an increase in the internal resistance of the battery 2000 during charging can be suppressed.

[0206] The volume ratio "v1:100-v1" of the positive electrode material 1000 to the second electrolyte material 100 contained in the positive electrode 201 may satisfy 30≦v1≦98. Here, v1 represents the volume ratio of the positive electrode material 1000 when the total volume of the positive electrode material 1000 and the second electrolyte material 100 contained in the positive electrode 201 is taken as 100. When 30≦v1 is satisfied, a sufficient energy density of the battery can be ensured. When v1≦98 is satisfied, the battery 2000 can operate at high output.

[0207] The thickness of the positive electrode 201 may be 10 μm or more and 500 μm or less. When the thickness of the positive electrode 201 is 10 μm or more, a sufficient energy density of the battery can be ensured. When the thickness of the positive electrode 201 is 500 μm or less, the battery 2000 can operate at high power.

[0208] The electrolyte layer 202 includes an electrolyte material. The electrolyte material may be, for example, a third solid electrolyte material. That is, the electrolyte layer 202 may be a solid electrolyte layer.

[0209] The third solid electrolyte material may be the same as the first solid electrolyte material 111 or the second electrolyte material 100 in embodiment 1. That is, the electrolyte layer 202 may contain the same material as the first solid electrolyte material 111 or the second electrolyte material 100 in embodiment 1.

[0210] According to the above configuration, the power density and charge / discharge characteristics of the battery 2000 can be further improved.

[0211] The third solid electrolyte material may be the same material as the first solid electrolyte material 111 in Embodiment 1. That is, the electrolyte layer 202 may contain the same material as the first solid electrolyte material 111 in Embodiment 1.

[0212] According to the above configuration, an increase in the internal resistance of the battery 2000 during charging due to oxidation of the electrolyte layer 202 can be suppressed, and the output density and charge / discharge characteristics of the battery 2000 can be further improved.

[0213] The third solid electrolyte material contained in the electrolyte layer 202 may be a halide solid electrolyte, a sulfide solid electrolyte, an oxide solid electrolyte, a polymer solid electrolyte, or a complex hydride solid electrolyte.

[0214] Examples of oxide solid electrolytes for the third solid electrolyte material include NASICON-type solid electrolytes, such as LiTi2(PO4)3 and its elemental substitution products, (LaLi)TiO3-based perovskite-type solid electrolytes, and Li 14 ZnGeO 16 , Li4SiO4, LiGeO4 and their element-substituted LISICON-type solid electrolytes, Li7La3Zr2O 12 Garnet-type solid electrolytes, such as those substituted with LiPO4 and its N-substituted derivatives, and glasses or glass ceramics based on Li-BO compounds such as LiBO2 and LiBO3, to which LiSO4, LiCO3, etc. are added, can be used.

[0215] As the polymer solid electrolyte of the third solid electrolyte material, for example, a compound of a polymer compound and a lithium salt can be used. The polymer compound may have an ethylene oxide structure. A polymer compound having an ethylene oxide structure can contain a large amount of lithium salt. This can further increase ionic conductivity. As the lithium salt, LiPF6, LiBF4, LiSbF6, LiAsF6, LiSO3CF3, LiN(SO2CF3)2, LiN(SO2C2F5)2, LiN(SO2CF3)(SO2C4F9), and LiC(SO2CF3)3 can be used. One lithium salt selected from the exemplified lithium salts can be used alone. Alternatively, a mixture of two or more lithium salts selected from the exemplified lithium salts can be used.

[0216] As the complex hydride solid electrolyte of the third solid electrolyte material, for example, LiBH4-LiI, LiBH4-P2S5, etc. can be used.

[0217] The electrolyte layer 202 may contain the third solid electrolyte material as a main component. That is, the electrolyte layer 202 may contain the third solid electrolyte material in a mass ratio of 50% or more (i.e., 50 mass% or more) relative to the entire electrolyte layer 202.

[0218] According to the above configuration, the charge / discharge characteristics of the battery can be further improved.

[0219] The electrolyte layer 202 may contain the third solid electrolyte material in a mass ratio relative to the entire electrolyte layer 202 of 70% or more (ie, 70 mass % or more).

[0220] According to the above configuration, the charge / discharge characteristics of the battery 2000 can be further improved.

[0221] The electrolyte layer 202 contains the third solid electrolyte material as a main component, and may further contain unavoidable impurities, or starting materials, by-products, and decomposition products used in synthesizing the third solid electrolyte material.

[0222] The electrolyte layer 202 may contain the third solid electrolyte material in a mass ratio of 100% (ie, 100 mass%) relative to the entire electrolyte layer 202, excluding unavoidable impurities, for example.

[0223] According to the above configuration, the charge / discharge characteristics of the battery 2000 can be further improved.

[0224] As described above, the electrolyte layer 202 may be made of only the third solid electrolyte material.

[0225] The electrolyte layer 202 may contain two or more of the materials listed as the third solid electrolyte material. For example, the electrolyte layer 202 may contain a halide solid electrolyte and a sulfide solid electrolyte.

[0226] The thickness of the electrolyte layer 202 may be 1 μm or more and 300 μm or less. When the thickness of the electrolyte layer 202 is 1 μm or more, the cathode 201 and the anode 203 are less likely to short-circuit. When the thickness of the electrolyte layer 202 is 300 μm or less, the battery 2000 can operate at high power.

[0227] The negative electrode 203 includes a material having the property of absorbing and releasing metal ions (for example, lithium ions). The negative electrode 203 includes, for example, a negative electrode active material.

[0228] The negative electrode active material may be a metal material, a carbon material, an oxide, a nitride, a tin compound, or a silicon compound. The metal material may be a single metal. Alternatively, the metal material may be an alloy. Examples of the metal material include lithium metal or a lithium alloy. Examples of the carbon material include natural graphite, coke, partially graphitized carbon, carbon fiber, spherical carbon, artificial graphite, and amorphous carbon. From the viewpoint of capacity density, silicon, tin, a silicon compound, or a tin compound may be used.

[0229] The negative electrode 203 may contain a solid electrolyte material. As the solid electrolyte material, the solid electrolyte material exemplified as the material constituting the electrolyte layer 202 may be used. With the above configuration, the lithium ion conductivity inside the negative electrode 203 is increased, and the battery 2000 can operate at high power.

[0230] The median diameter of the negative electrode active material particles may be 0.1 μm or more and 100 μm or less. When the median diameter of the negative electrode active material particles is 0.1 μm or more, the negative electrode active material particles and the solid electrolyte material can form a well-dispersed state in the negative electrode. This improves the charge / discharge characteristics of the battery 2000. When the median diameter of the negative electrode active material particles is 100 μm or less, lithium diffusion within the negative electrode active material particles is accelerated. This allows the battery 2000 to operate at high power.

[0231] The median diameter of the negative electrode active material particles may be larger than the median diameter of the solid electrolyte material contained in the negative electrode 203. This allows the negative electrode active material particles and the solid electrolyte material to be well dispersed.

[0232] The volume ratio "v2:100-v2" of the negative electrode active material particles to the solid electrolyte material contained in the negative electrode 203 may satisfy 30≦v2≦95. Here, v2 represents the volume ratio of the negative electrode active material particles when the total volume of the negative electrode active material particles and the solid electrolyte material contained in the negative electrode 203 is taken as 100. When 30≦v2 is satisfied, a sufficient energy density of the battery can be ensured. When v2≦95 is satisfied, the battery 2000 can operate at high output.

[0233] The thickness of the negative electrode 203 may be 10 μm or more and 500 μm or less. When the thickness of the negative electrode 203 is 10 μm or more, a sufficient energy density of the battery 2000 can be ensured. When the thickness of the negative electrode 203 is 500 μm or less, the battery 2000 can operate at high power.

[0234] At least one selected from the group consisting of the positive electrode 201, the electrolyte layer 202, and the negative electrode 203 may contain a binder to improve adhesion between particles. The binder is used to improve the binding properties of the materials constituting the electrode. Examples of binders include polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, aramid resin, polyamide, polyimide, polyamideimide, polyacrylonitrile, polyacrylic acid, polymethyl ester of acrylic acid, polyethyl ester of acrylic acid, polyhexyl ester of acrylic acid, polymethacrylic acid, polymethyl ester of methacrylic acid, polyethyl ester of methacrylic acid, polyhexyl ester of methacrylic acid, polyvinyl acetate, polyvinylpyrrolidone, polyether, polyethersulfone, hexafluoropolypropylene, styrene-butadiene rubber, and carboxymethyl cellulose. The binder may be a copolymer of two or more materials selected from the group consisting of tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether, vinylidene fluoride, chlorotrifluoroethylene, ethylene, propylene, pentafluoropropylene, fluoromethyl vinyl ether, acrylic acid, and hexadiene, or a mixture of two or more materials selected from these.

[0235] At least one of the positive electrode 201 and the negative electrode 203 may contain a conductive additive to enhance electronic conductivity. Examples of conductive additives that can be used include graphites such as natural graphite or artificial graphite, carbon blacks such as acetylene black and ketjen black, conductive fibers such as carbon fiber and metal fiber, metal powders such as carbon fluoride and aluminum, conductive whiskers such as zinc oxide and potassium titanate, conductive metal oxides such as titanium oxide, and conductive polymer compounds such as polyaniline, polypyrrole, and polythiophene. Using a carbon conductive additive as the conductive additive can reduce costs.

[0236] The shape of the battery 2000 in the second embodiment may be, for example, a coin type, a cylindrical type, a square type, a sheet type, a button type, a flat type, or a laminated type.

[0237] The battery 2000 in the second embodiment may be manufactured, for example, by preparing the positive electrode material 1000 in the first embodiment, a material for forming the electrolyte layer, and a material for forming the negative electrode, and by using a known method to fabricate a laminate in which the positive electrode, the electrolyte layer, and the negative electrode are arranged in this order.

[0238] (Embodiment 3) The following describes the third embodiment. Explanations that overlap with the second embodiment will be omitted as appropriate.

[0239] FIG. 4 is a cross-sectional view showing a schematic configuration of a battery 3000 according to the third embodiment.

[0240] The battery 3000 in the third embodiment includes a positive electrode 201 , an electrolyte layer 202 , and a negative electrode 203 .

[0241] The positive electrode 201 includes the positive electrode material 1000 in the first embodiment.

[0242] The electrolyte layer 202 is disposed between the positive electrode 201 and the negative electrode 203 .

[0243] The electrolyte layer 202 includes a first electrolyte layer 301 and a second electrolyte layer 302 , where the first electrolyte layer 301 contacts the positive electrode 201 and the second electrolyte layer 302 contacts the negative electrode 203 .

[0244] According to the above configuration, it is possible to suppress an increase in the internal resistance of the battery 3000 during charging.

[0245] The first electrolyte layer 301 may comprise the same material as the first solid electrolyte material 111 .

[0246] By including the first solid electrolyte material 111, which has excellent oxidation resistance, in the first electrolyte layer 301 in contact with the positive electrode 201, oxidative decomposition of the first electrolyte layer 301 can be suppressed, and an increase in the internal resistance of the battery 3000 during charging can be suppressed.

[0247] The second electrolyte layer 302 may contain a material different from the first solid electrolyte material 111.

[0248] From the viewpoint of the reduction resistance of the solid electrolyte material, the reduction potential of the solid electrolyte material contained in first electrolyte layer 301 may be lower than the reduction potential of the solid electrolyte material contained in second electrolyte layer 302. According to the above configuration, the solid electrolyte material contained in first electrolyte layer 301 can be used without being reduced, thereby improving the charge / discharge efficiency of battery 3000.

[0249] For example, the second electrolyte layer 302 may contain a sulfide solid electrolyte. Here, the reduction potential of the sulfide solid electrolyte contained in the second electrolyte layer 302 is lower than the reduction potential of the solid electrolyte material contained in the first electrolyte layer 301. According to the above configuration, the solid electrolyte material contained in the first electrolyte layer 301 can be used without being reduced. This allows the charge / discharge efficiency of the battery 3000 to be improved.

[0250] The thickness of the first electrolyte layer 301 and the second electrolyte layer 302 may be 1 μm or more and 300 μm or less. When the thickness of the first electrolyte layer 301 and the second electrolyte layer 302 is 1 μm or more, the positive electrode 201 and the negative electrode 203 are less likely to short-circuit. When the thickness of the first electrolyte layer 301 and the second electrolyte layer 302 is 300 μm or less, the battery 3000 can operate at high power. [Example]

[0251] Hereinafter, the present disclosure will be described in more detail with reference to examples.

[0252] Example 1 [Preparation of the first solid electrolyte material] In an argon glove box (hereinafter referred to as "argon atmosphere") with a dew point of -60°C or less, LiF, TiF, and MgF were weighed as raw material powders so as to have a molar ratio of LiF:TiF:MgF = 3:0.5:0.5. Then, a planetary ball mill (Fritsch, P-5 type) was used to mill the powders at 200 rpm for 24 hours to obtain LiTi as the first solid electrolyte material of Example 1. 0.5 Mg 0.5 A powder of F6 was obtained.

[0253] [Preparation of a cathode active material having a surface coated with a first solid electrolyte material] In an argon atmosphere, Li(Ni,Co,Mn)O2 (hereinafter referred to as NCM), which is a positive electrode active material, and the first solid electrolyte material of Example 1 were weighed out to a mass ratio of 100:3. These materials were placed in a dry particle compositing device, Nobilta (manufactured by Hosokawa Micron), and a compositing process was carried out under conditions of 6000 rpm and 30 minutes, thereby obtaining a positive electrode active material whose surface was coated with the first solid electrolyte material.

[0254] [Preparation of second electrolyte material] In an argon atmosphere, raw material powders LiBr, YBr3, LiCl, and YCl3 were weighed out so that the molar ratio of LiBr:YBr3:LiCl:YCl3 = 1:1:5:1. Then, using a planetary ball mill (Fritsch, P-7 model), milling was performed for 25 hours at 600 rpm to obtain Li3YBr2Cl4 powder as the second electrolyte material. In the following Examples 2 to 4 and Comparative Example 1, Li3YBr2Cl4 was used as the second electrolyte material.

[0255] [Preparation of cathode material] The positive electrode active material whose surface was coated with the first solid electrolyte material of Example 1 and the second electrolyte material Li3YBr2Cl4 were weighed out to have a mass ratio of 81.55:18.45 and mixed in a mortar to produce the positive electrode material of Example 1.

[0256] <Example 2> [Preparation of the first solid electrolyte material] In an argon atmosphere, LiF, TiF, and CaF were weighed as raw material powders so that the molar ratio of LiF:TiF:CaF was 3:0.5:0.5. Then, a planetary ball mill (Fritsch, P-7) was used to mill the powders at 500 rpm for 12 hours to obtain LiTi as the first solid electrolyte material of Example 2. 0.5 Ca 0.5 A powder of F6 was obtained.

[0257] [Preparation of a cathode active material having a surface coated with a first solid electrolyte material] In an argon atmosphere, NCM, which is a positive electrode active material, and the first solid electrolyte material of Example 2 were weighed out to a mass ratio of 100:3. These materials were placed in a dry particle compositing device, Nobilta (manufactured by Hosokawa Micron Co., Ltd.), and a compositing process was carried out at 6000 rpm for 30 minutes, thereby obtaining a positive electrode active material whose surface was coated with the first solid electrolyte material of Example 2.

[0258] [Preparation of cathode material] The positive electrode active material whose surface was coated with the first solid electrolyte material of Example 2 and the second electrolyte material Li3YBr2Cl4 were weighed out to a mass ratio of 81.55:18.45 and mixed in a mortar to produce the positive electrode material of Example 2.

[0259] Example 3 [Preparation of the first solid electrolyte material] In an argon atmosphere, LiF, TiF, and AlF were weighed as raw material powders so that the molar ratio of LiF:TiF:AlF was 2.6:0.4:0.6. Then, a planetary ball mill (Fritsch, P-7) was used to mill the powders at 500 rpm for 12 hours to obtain LiF as the first solid electrolyte material of Example 3. 2.6 Ti 0.4 Al 0.6 A powder of F6 was obtained.

[0260] [Preparation of a cathode active material having a surface coated with a first solid electrolyte material] In an argon atmosphere, NCM, which is a positive electrode active material, and the first solid electrolyte material of Example 3 were weighed out to a mass ratio of 100:3. These materials were placed in a dry particle compositing device, Nobilta (manufactured by Hosokawa Micron Co., Ltd.), and a compositing process was carried out under conditions of 6000 rpm and 30 minutes, thereby obtaining a positive electrode active material whose surface was coated with the first solid electrolyte material of Example 3.

[0261] [Preparation of cathode material] The positive electrode active material whose surface was coated with the first solid electrolyte material of Example 3 and the second electrolyte material Li3YBr2Cl4 were weighed out to a mass ratio of 81.55:18.45 and mixed in a mortar to produce the positive electrode material of Example 3.

[0262] Example 4 [Preparation of the first solid electrolyte material] In an argon atmosphere, LiF, TiF, and ZrF were weighed as raw material powders so that the molar ratio of LiF:TiF:ZrF was 3:0.5:0.5. Then, a planetary ball mill (Fritsch, P-5) was used to mill the powders at 200 rpm for 24 hours to obtain LiTi as the first solid electrolyte material of Example 4. 0.5 Zr 0.5 A powder of F7 was obtained.

[0263] [Preparation of a cathode active material having a surface coated with a first solid electrolyte material] In an argon atmosphere, NCM, which is a positive electrode active material, and the first solid electrolyte material of Example 4 were weighed out to a mass ratio of 100:3. These materials were placed in a dry particle compositing device, Nobilta (manufactured by Hosokawa Micron Co., Ltd.), and a compositing process was carried out under conditions of 6000 rpm and 30 minutes, thereby obtaining a positive electrode active material whose surface was coated with the first solid electrolyte material of Example 4.

[0264] [Preparation of cathode material] The positive electrode active material whose surface was coated with the first solid electrolyte material of Example 4 and the second electrolyte material Li3YBr2Cl4 were weighed out to have a mass ratio of 81.55:18.45 and mixed in a mortar to produce the positive electrode material of Example 4.

[0265] <Comparative Example 1> [Preparation of cathode material] The positive electrode active material NCM and the second electrolyte material Li3YBr2Cl4 were weighed out to have a mass ratio of 81.55:18.45 and mixed in a mortar to prepare a positive electrode material of Comparative Example 1.

[0266] [Battery construction] Batteries using the positive electrode materials of Examples 1 to 4 and Comparative Example 1 were fabricated by the following steps.

[0267] First, 60 mg of Li3YBr2Cl4 was placed in an insulating outer cylinder, and this was press-molded at a pressure of 80 MPa. The second electrolyte material prepared in Example 1 was used as Li3YBr2Cl4.

[0268] Next, 17.2 mg of a positive electrode material was added, and the mixture was pressure-molded at a temperature of 150° C. and a pressure of 300 MPa, thereby obtaining a laminate consisting of a positive electrode and a solid electrolyte layer.

[0269] Next, metal In, metal Li, metal In, metal In, metal Li, metal In were stacked in this order on the side of the solid electrolyte layer opposite to the side in contact with the positive electrode. The metal In was 200 μm thick, and the metal Li was 200 μm thick. This was then press-molded at a pressure of 80 MPa to produce a laminate consisting of a positive electrode, solid electrolyte layer, and negative electrode.

[0270] Next, stainless steel current collectors were placed on the top and bottom of the laminate, and current collecting leads were attached to the current collectors.

[0271] Finally, an insulating ferrule was used to isolate the inside of the insulating outer cylinder from the outside atmosphere and to seal it, thereby completing a battery.

[0272] In this manner, the batteries of Examples 1 to 4 and Comparative Example 1 were fabricated.

[0273] <Example 5> [Preparation of second electrolyte material] In an argon atmosphere, Li2S and P2S5 were weighed out so that the molar ratio of Li2S:P2S5 was 75:25. These were then pulverized and mixed in a mortar. Then, a planetary ball mill (Fritsch, P-7) was used to mill the mixture at 510 rpm for 10 hours to obtain a glassy solid electrolyte. The glassy solid electrolyte was then heat-treated at 270°C for 2 hours in an inert atmosphere. This resulted in a second electrolyte material, Li2S-P2S5, which was a glass-ceramic solid electrolyte. In the following Examples 6 to 8 and Comparative Example 2, Li2S-P2S5 was used as the second electrolyte material.

[0274] [Preparation of cathode material] The positive electrode active material whose surface was coated with the first solid electrolyte material of Example 1 and the second electrolyte material Li2S-P2S5 were weighed out to a mass ratio of 81.2:18.8 and mixed in a mortar to produce the positive electrode material of Example 5.

[0275] Example 6 [Preparation of cathode material] The positive electrode active material whose surface was coated with the first solid electrolyte material of Example 2 and the second electrolyte material Li2S-P2S5 were weighed out to a mass ratio of 81.2:18.8 and mixed in a mortar to produce the positive electrode material of Example 6.

[0276] Example 7 [Preparation of cathode material] The positive electrode active material whose surface was coated with the first solid electrolyte material of Example 3 and the second electrolyte material Li2S-P2S5 were weighed out to a mass ratio of 81.2:18.8 and mixed in a mortar to produce the positive electrode material of Example 7.

[0277] Example 8 [Preparation of cathode material] The positive electrode active material whose surface was coated with the first solid electrolyte material of Example 4 and Li2S-P2S5 as the second electrolyte material were weighed out to a mass ratio of 81.2:18.8 and mixed in a mortar to produce the positive electrode material of Example 8.

[0278] <Comparative Example 2> [Preparation of cathode material] The positive electrode active material NCM and the second electrolyte material Li2S-P2S5 were weighed out to have a mass ratio of 81.2:18.8 and mixed in a mortar to prepare a positive electrode material of Comparative Example 2.

[0279] [Battery construction] Batteries using the positive electrode materials of Examples 5 to 8 and Comparative Example 2 were fabricated by the following steps.

[0280] First, 96 mg of Li2S-P2S5 was placed in an insulating outer cylinder, and this was press-molded at a pressure of 80 MPa. The second electrolyte material prepared in Example 5 was used for Li2S-P2S5.

[0281] Next, 17.76 mg of the positive electrode was added, and the mixture was pressure-molded at a pressure of 700 MPa, thereby obtaining a laminate consisting of the positive electrode and the solid electrolyte layer.

[0282] Next, metal In, metal Li, metal In, metal In, metal Li, metal In were stacked in this order on the side of the solid electrolyte layer opposite to the side in contact with the positive electrode. The metal In was 200 μm thick, and the metal Li was 200 μm thick. This was then press-molded at a pressure of 80 MPa to produce a laminate consisting of a positive electrode, solid electrolyte layer, and negative electrode.

[0283] Next, stainless steel current collectors were placed on the top and bottom of the laminate, and current collecting leads were attached to the current collectors.

[0284] Finally, an insulating ferrule was used to isolate and seal the inside of the insulating outer cylinder from the outside atmosphere, thereby completing a battery.

[0285] In this manner, the batteries of Examples 5 to 8 and Comparative Example 2 were fabricated.

[0286] [Charging test] Using the batteries of Examples 1 to 8 and Comparative Examples 1 and 2 described above, charging tests were carried out under the following conditions.

[0287] The battery was placed in a constant temperature bath at 85°C.

[0288] The battery was charged at a constant current of 140 μA at a rate of 0.05 C (20-hour rate) relative to the theoretical capacity of the battery. The end-of-charge voltage was 3.68 V (4.3 V vs. Li / Li + ) Next, the voltage was 3.68V (4.3V vs. Li / Li + The charge termination current was set to 28 μA, which corresponds to a 0.01 C rate (100-hour rate).

[0289] Next, the battery was stored in a thermostatic chamber at 85°C for 72 hours.

[0290] Next, AC impedance analysis was performed on the stored batteries. The voltage amplitude was ±10 mV and the frequency was 10 7 From 10 -2 The frequency was measured at 1000 kJ / s, and the frequency was measured at 1000 kJ / s. The measurement was performed using an electrochemical measurement system manufactured by Solartron. The semicircular waveforms in the obtained Nyquist diagram are attributed to the resistance of the positive electrode and the resistance of the negative electrode, In. Therefore, the resistance value of the positive electrode was calculated by performing a fitting analysis of the semicircular waveforms in the Nyquist diagram.

[0291] The resistance values ​​of the positive electrodes of Examples 1 to 8 and Comparative Examples 1 and 2 are shown in Table 1.

[0292] [Table 1]

[0293] ≪Consideration≫ As can be seen from Table 1, the battery of Example 1 exhibits low positive electrode resistance. This is because the first solid electrolyte material, which has high oxidation resistance, covers at least a portion of the surface of the positive electrode active material, thereby suppressing contact between the positive electrode active material and the second electrolyte material, Li3YBr2Cl4, and thereby suppressing an increase in the positive electrode resistance. On the other hand, as shown by the results of Comparative Example 1, a battery using a positive electrode material in which the surface of the positive electrode active material is not covered with the first solid electrolyte material exhibits a high resistance value of 72.2 Ω. This is because the second electrolyte material, the halide solid electrolyte Li3YBr2Cl4, oxidizes and decomposes during battery charging, and the oxidized decomposition product functions as a resistive layer, thereby increasing the positive electrode resistance.

[0294] As shown by the results of Examples 2 to 4, even when M1 contained in the first solid electrolyte material is Ca, Al, or Zr, a low positive electrode resistance can be achieved, similar to Example 1.

[0295] As shown by the results of Examples 5 to 8, even when the second electrolyte material is the sulfide solid electrolyte Li2S-P2S5, low positive electrode resistance can be achieved, as in Examples 1 to 4. On the other hand, as shown by the results of Comparative Example 2, as in Comparative Example 1, a battery using a positive electrode material in which the surface of the positive electrode active material is not covered with the first solid electrolyte material exhibits high positive electrode resistance.

[0296] As shown by the above examples, according to the present disclosure, it is possible to suppress an increase in the internal resistance of a battery during charging. [Industrial Applicability]

[0297] The battery of the present disclosure can be used, for example, as an all-solid-state lithium-ion secondary battery.

Claims

1. A positive electrode material for a lithium secondary battery, comprising: a positive electrode active material, and a first solid electrolyte material that covers at least a portion of the surface of the positive electrode active material; Including, where: The first solid electrolyte material includes a material represented by the following composition formula (1): Li 6-(4-2x1)b1 (Ti 1-x1 M1 x1) b1 F 6 ...Formula (1) wherein M1 is at least one element selected from the group consisting of Ca and Mg, and 0<x1<1 and 0<b1≦3 are satisfied. Positive electrode material.

2. The first solid electrolyte material is Li 3 Ti 0.5 Mg 0.5 F 6 Including, The positive electrode material according to claim 1 .

3. The first solid electrolyte material is Li 3 Ti 0.5 Ca 0.5 F 6 Including, The positive electrode material according to claim 1 .

4. A positive electrode material for a lithium secondary battery, comprising: a positive electrode active material, and a first solid electrolyte material that covers at least a portion of the surface of the positive electrode active material; Including, where: The first solid electrolyte material includes a material represented by the following composition formula (2): Li 6-(4-x2)b2 (Ti 1-x2 M1 x2 ) b2 F 6 ...Formula (2) wherein M1 is Al, and 0<x2<1 and 0<b2≦1.5 are satisfied. Positive electrode material.

5. The first solid electrolyte material is Li 2.6 Ti 0.4 Al 0.6 F 6 Including, The positive electrode material according to claim 4.

6. A positive electrode material for a lithium secondary battery, comprising: a positive electrode active material, and a first solid electrolyte material that covers at least a portion of the surface of the positive electrode active material; Including, where: the first solid electrolyte material includes Li 3 Ti 0.5 Zr 0.5 F 7 ; Positive electrode material.

7. Further comprising a second electrolyte material that is different from the first solid electrolyte material. The positive electrode material according to any one of claims 1 to 6.

8. The second electrolyte material is represented by the following composition formula (5): Li α M2 β X γ ... Formula (5) where: α, β, and γ are values ​​greater than 0; M2 includes at least one of a metal element other than Li and a metalloid element, X is at least one element selected from the group consisting of F, Cl, Br, and I; The positive electrode material according to claim 7.

9. M2 includes Y. The positive electrode material according to claim 8.

10. The composition formula (5) is ２．５≦α≦３、 １≦β≦１．１、 γ=6, fulfill, The positive electrode material according to claim 8 or 9.

11. The second electrolyte material includes a sulfide solid electrolyte. The positive electrode material according to claim 7.

12. The sulfide solid electrolyte contains lithium sulfide and phosphorus sulfide. The positive electrode material according to claim 11.

13. The sulfide solid electrolyte is Li 2 S-P 2 S 5 That is, The positive electrode material according to claim 11 or 12.

14. the second electrolyte material is an electrolyte solution containing a lithium salt and a solvent; The positive electrode material according to claim 7.

15. The positive electrode active material includes lithium nickel-cobalt-manganese oxide. The cathode material according to any one of claims 1 to 14.

16. the first solid electrolyte material is provided between the positive electrode active material and the second electrolyte material; The positive electrode material according to claim 7.

17. A positive electrode comprising the positive electrode material of any one of claims 1 to 6 and 15. a negative electrode, and an electrolyte layer disposed between the positive electrode and the negative electrode; Equipped with battery.

18. A positive electrode comprising the positive electrode material according to any one of claims 7 to 14 and 16. a negative electrode, and an electrolyte layer disposed between the positive electrode and the negative electrode; Equipped with the electrolyte layer contains the same material as the first solid electrolyte material or the second electrolyte material; battery.

19. the electrolyte layer contains the same material as the first solid electrolyte material; 20. The battery of claim 18.

20. the electrolyte layer includes a first electrolyte layer and a second electrolyte layer; the first electrolyte layer is in contact with the positive electrode, and the second electrolyte layer is in contact with the negative electrode; 19. The battery of claim 17 or 18.

21. the first electrolyte layer contains the same material as the first solid electrolyte material; 21. The battery of claim 20.

22. the second electrolyte layer includes a material different from the first solid electrolyte material; 22. The battery of claim 20 or 21.

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