Battery material, positive electrode and battery

Abstract

A battery material containing a solid electrolyte material containing an alkali metal element, a metal element or a semimetal element other than the alkali metal element, and a halogen element, and an ionic liquid containing an alkali metal ion as a cation.

Description

Technical Field

[0001] The present disclosure relates to battery materials, positive electrodes, and batteries. Background Art

[0002] Batteries such as lithium-ion batteries that perform charge and discharge with the movement of metal ions between a positive electrode and a negative electrode have been actively studied because of their high capacity. As electrolytes for lithium-ion batteries and the like, solutions containing lithium salts including organic solvents or ionic liquids are known, but research on solid electrolytes has been carried out from the viewpoints of safety and processability. As solid electrolytes, various types of compounds such as oxide-based solid electrolytes and sulfide-based solid electrolytes are known.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: International Publication No. 2019 / 135346 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] Solid electrolyte materials are sometimes used not only in the electrolytes of batteries but also in positive electrodes and negative electrodes to ensure ion conductivity (Patent Document 1 and the like). However, most solid electrolyte materials cannot form a sufficient interface from the viewpoint of flexibility. Therefore, in order to improve flexibility, it has been proposed to mix with additives such as polymers, organic solvents, and ionic liquids to improve flexibility. However, as a result of in-depth research by the present inventors, when the materials (battery materials) for forming each component of a battery contain such additives, a chemical reaction sometimes occurs between the conventional additives and the solid electrolyte, and there are problems with stability. Particularly in halide solid electrolytes, this tendency is significant.

[0008] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a battery material, a positive electrode, and a battery having high stability.

[0009] Means for Solving the Problems

[0010] The present disclosure includes the following embodiments [1] to [9].

[0011] [1] A battery material, wherein

[0012] it contains a solid electrolyte material and an ionic liquid,

[0013] the above solid electrolyte material contains an alkali metal element, a metal element other than the alkali metal element, or a metalloid element and a halogen element,

[0014] the above ionic liquid contains an alkali metal ion as a cation.

[0015] [2] The battery material according to [1], wherein

[0016] it further contains a positive electrode active material.

[0017] [3] The battery material according to [2], wherein

[0018] the ratio of the volume of the above positive electrode active material to the total volume of the above positive electrode active material and the above solid electrolyte material is 0.50 to 0.99.

[0019] [4] The battery material according to [2] or [3], wherein

[0020] the positive electrode active material is a lithium-containing composite oxide containing nickel.

[0021] [5] The battery material according to any one of [1] to [4], wherein

[0022] the above solid electrolyte material contains A α M β Z γ D ζ O η the compound represented by,

[0023] wherein A is an alkali metal, M is a metal element or a semi-metal element other than an alkali metal element, Z is a halogen element, D is at least one of P and S, 1.6 ≤ α ≤ 3.5, 0 < β ≤ 1.2, 3 ≤ γ ≤ 6.5, 0 ≤ ζ ≤ 0.5, 0 ≤ η ≤ 2.

[0024] [6] The battery material according to any one of [1] to [5], wherein

[0025] the ratio of the volume of the above solid electrolyte material to the total volume of the above solid electrolyte material and the above ionic liquid is 0.30 to 0.90.

[0026] [7] The battery material according to any one of [1] to [6], wherein

[0027] it further contains a binder resin.

[0028] [8] A positive electrode, wherein

[0029] it contains the battery material according to any one of [1] to [7].

[0030] [9] A battery, wherein

[0031] it includes the positive electrode described in [8].

[0032]

[10] A battery component, wherein

[0033] It is a laminate having a first layer and a second layer laminated on the first layer. The first layer contains a solid electrolyte material, and the second layer contains an ionic liquid containing an alkali metal ion as a cation.

[0034]

[11] The battery member according to

[10] , wherein,

[0035] The first layer contains a polymer.

[0036]

[12] A battery material,

[0037] which contains a solid electrolyte material, an alkali metal salt, and an ether compound,

[0038] The solid electrolyte material contains an alkali metal element, a metal element or a metalloid element other than the alkali metal element, and a halogen element,

[0039] At least a part of the ether compound forms a coordination bond with an alkali metal ion.

[0040] Advantageous Effects of the Invention

[0041] According to the present disclosure, it is possible to provide a battery material, a positive electrode, and a battery with high stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a diagram showing X-ray diffraction patterns obtained for the battery materials of Example 1, Example 2, and Comparative Example 1.

[0043] Figure 2 It is a graph of the ionic conductivity (σ) of the battery material of Example 1 with respect to 1000 / T (T is the absolute temperature).

[0044] Figure 3 It is a diagram showing the X-ray diffraction pattern of the battery material of Comparative Example 1.

[0045] Figure 4 It is a diagram showing the results of impedance measurement of a symmetric battery. DETAILED DESCRIPTION

[0046] The battery material of this embodiment includes a solid electrolyte material and an ionic liquid. The solid electrolyte material contains an alkali metal element, a metal element or a metalloid element other than the alkali metal element, and a halogen element. The ionic liquid contains an alkali metal ion as a cation. It should be noted that in the battery material of this embodiment, the solid electrolyte and the ionic liquid can also be mixed, but the ionic liquid can also be coated on the surface of the composition containing the solid electrolyte (that is, at least a part of the ionic liquid is included as a coating layer). In this case, a part of the ionic liquid can also infiltrate into the composition. The shape of the composition containing the solid electrolyte is not particularly limited, but can be in the form of a sheet, granules, etc. The solid electrolyte material can be a material that satisfies at least one of the following (A) to (C). (A) The solid electrolyte material contains In as a metal element other than the alkali metal element. (B) The solid electrolyte material contains Zr as a metal element other than the alkali metal element and contains two or more halogen elements. (C) The solid electrolyte material further contains an oxygen element.

[0047] The battery material of this embodiment is a composition for forming a positive electrode, a negative electrode, or an electrolyte (solid electrolyte) of a battery. When the battery material is a material for forming a positive electrode (positive electrode material), the battery material can contain a positive electrode active material. In addition, when the battery material is a material for forming a negative electrode (negative electrode material), the battery material can contain a negative electrode active material.

[0048] The alkali metal element contained in the solid electrolyte material can be any one of Li, Na, K, Rb, and Cs, but can contain at least one of Li, Na, and K, can contain at least one of Li and Na, and can contain Li.

[0049] Among the alkali metal elements contained in the solid electrolyte material, the proportion of one alkali metal element can be 80 mol% or more, can be 90 mol% or more, and can be 95 mol% or more. This one alkali metal element can be at least one of Li, Na, and K, can be at least one of Li and Na, and can be Li.

[0050] The content of the alkali metal element in the solid electrolyte material can be 15 to 30 mol%, can be 18 to 28 mol%, and can be 20 to 27 mol% relative to the total amount of atoms contained in the solid electrolyte material.

[0051] Examples of the metal element or metalloid element other than the alkali metal element include elements with a valence of 2 to 5, and can include one or more selected from the group consisting of elements with a valence of 3 and elements with a valence of 4. The solid electrolyte material can contain one or two or more metal elements or metalloid elements other than the alkali metal element.

[0052] Examples of divalent elements include alkaline earth metals and Zn. Examples of alkaline earth metals include at least one of Mg, Ca, Sr, and Ba, at least one of Mg and Ca, and Mg. Examples of trivalent metal elements include Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Y, Al, Ga, In, Bi, and Sb. Examples of tetravalent elements include Zr, Ti, Hf, and Sn, and Zr is acceptable. Examples of pentavalent elements include Nb and Ta. Examples of elements with a valence of 5 or higher include W.

[0053] The metal element or metalloid element other than the alkali metal element may include at least one of In and Zr. The content of the metal element or metalloid element other than the alkali metal element in the solid electrolyte material is preferably 8 to 15 mol%, more preferably 8 to 13 mol%, and still more preferably 9 to 12 mol% based on all the elements contained in the solid electrolyte material.

[0054] The solid electrolyte material may contain 70 mol% or more of one element among the metal elements or metalloid elements other than the alkali metal element with respect to the total amount of the metal elements or metalloid elements other than the alkali metal element. 75 mol% or more may be contained, and 80 mol% or more may be contained. In this case, as the one element, it may be a trivalent or tetravalent element, and may be In or Zr. In this case, the solid electrolyte material contains a metal element or metalloid element other than the alkali metal element other than the one element (also referred to as doping element X1). The doping element X1 is an element different from the one element. When the one element is a trivalent element, the doping element X1 may be at least one element selected from the group consisting of Zr, Sn, Ti, Nb, Ta, Bi, and Y, and may be at least one element selected from the group consisting of Zr, Sn, Nb, and Ta. When the one element is a tetravalent element, the doping element X1 may be at least one element selected from the group consisting of Bi, Al, Ga, In, Sc, Sm, Sb, La, Zn, Sn, and alkaline earth metals, and may be at least one element selected from the group consisting of Bi, La, Zn, and Sn.

[0055] The halogen element contained in the solid electrolyte material of the present embodiment may be any of F, Cl, Br, and I, but may contain at least one of Cl, Br, and I, may contain at least one of Cl and Br, and may contain Cl. The ion conductive substance may also contain only one halogen element, but may also contain two or more halogen elements.

[0056] The content of halogen elements in the solid electrolyte material is based on all the elements contained in the halogen elements, preferably 40 to 70 mol%, more preferably 45 to 68 mol%.

[0057] The solid electrolyte material can contain one element of the halogen elements in an amount of 80 mol% or more, 85 mol% or more, or 90 mol% or more relative to the total amount of the halogen elements. This one halogen element can be Cl or Br, and can be Cl. In this case, the solid electrolyte material contains halogen elements other than this one halogen element (also referred to as doping element X2). When this one halogen element is Cl, the doping element X2 can be at least one of Br and I, and can be Br. When the solid electrolyte material contains Zr as a metal element other than an alkali metal element, the solid electrolyte material can contain two or more halogen elements, can contain Cl and a halogen element other than Cl, and can contain Cl and Br. The content of the halogen element other than Cl or Br can be 10 mol% or less, 0.1 to 10 mol%, or 1 to 8 mol% relative to the total amount of the halogen elements contained in the solid electrolyte material.

[0058] The solid electrolyte material can contain at least one of P and S (also referred to as doping element X3). The content of the doping element X3 in the solid electrolyte material can be 0.05 to 5 mol%, 0.1 to 3 mol%, 0.2 to 2 mol%, or 0.3 to 1 mol% relative to the total amount of atoms contained in the solid electrolyte material.

[0059] When the solid electrolyte material contains at least one of P and S, the solid electrolyte material can contain a tetravalent metal element or a metalloid element. Examples of the tetravalent metal element or metalloid element include Zr, Ti, Hf, etc., and can be Zr. In addition, as the doping element X2, it can also contain at least one of Hf and Mg.

[0060] The content of the doping element X3 in the solid electrolyte material can be 50 mol% or less, 1 to 30 mol%, 1 to 20 mol%, or 2 to 10 mol% of the content of the tetravalent metal element or metalloid element. The content of the doping element X in the solid electrolyte material can be 20 mol% or less, 15 mol% or less, 10 mol% or less, or 8 mol% or less of the content of the tetravalent metal element or metalloid element.

[0061] The solid electrolyte material can have a hexagonal crystal structure and can belong to the space group P6 3Crystal structure of mc. The solid electrolyte material having a hexagonal crystal structure may contain at least one element selected from the group consisting of Sc, La, Y, Ga, In, Bi, Sb, Ge, Zr, Sn, Nb, and Ta, and may contain Sc.

[0062] The solid electrolyte material may contain a compound represented by the following formula (A).

[0063] A α M β Z γ D ζ O η (A)

[0064] In the formula, A is an alkali metal, M is a metal element or a semi-metal element other than an alkali metal element, Z is a halogen element, D is at least one of P and S, 1.6 ≤ α ≤ 3.5, 0 < β ≤ 1.2, 3 ≤ γ ≤ 6.5, 0 ≤ ζ ≤ 0.5, and 0 ≤ η ≤ 2.

[0065] Examples of the compound represented by the formula (A) include compounds represented by the following formulas (1) to (3).

[0066] A α1 M β1 Z 6-δ1 X1 ε11 X2 ε12 (1)

[0067] A α2 M β2 X2 ε21 Z 6-γ2 X1 ε22 (2)

[0068] A α3 M β3 X1 ε31 Z δ3 D ζ O η (3)

[0069] In formula (1), A, M, and Z are an alkali metal element, a trivalent metal element or a metalloid element, and a halogen element, respectively. As specific examples, the above elements can be cited. M preferably contains In. X1 and X2 are a doping element X1 and a doping element X2, respectively. As specific examples, the above elements can be cited. It can be 2 ≤ α1 ≤ 3.5, and it can be 2.5 ≤ α1 ≤ 3. It can be 0.5 ≤ β1 ≤ 1.1, and it can be 0.5 ≤ β1 ≤ 1. It can be 0 ≤ δ1 ≤ 1, and it can be 0 ≤ δ1 ≤ 0.5. It can be 0 ≤ ε11 ≤ 0.7, it can be 0 < ε11 ≤ 0.5, and it can be 0.01 ≤ ε11 ≤ 0.3. It can be 0 ≤ ε12 ≤ 0.7, it can be 0 < ε11 ≤ 0.5, and it can be 0.01 ≤ ε11 ≤ 0.3.

[0070] In formula (2), A, M, and Z are an alkali metal element, a tetravalent metal element or a metalloid element, and a halogen element, respectively. As specific examples, the above elements can be cited. M preferably contains Zr. X1 and X2 are a doping element X1 and a doping element X2, respectively. As specific examples, the above elements can be cited. It can be 1.6 ≤ α2 ≤ 2.5, it can be 1.8 ≤ α2 ≤ 2.4, and it can be 2 ≤ α2 ≤ 2.3. It can be 0 < β2 ≤ 1.1, it can be 0.5 ≤ β2 ≤ 1, and it can be 0.8 ≤ β2 ≤ 1. It can be 0 ≤ γ2 < 1, it can be 0.01 ≤ γ2 ≤ 0.8, it can be 0.02 ≤ γ2 ≤ 0.7, it can be 0.1 ≤ γ2 ≤ 0.6, and it can be 0.2 ≤ γ2 ≤ 0.6. It can be 0 ≤ ε21 ≤ 0.7, it can be 0 < ε21 ≤ 0.5, and it can be 0.01 ≤ ε21 ≤ 0.3. It can be 0 ≤ ε22 ≤ 0.8, and it can be 0 < ε21 ≤ 0.6. When X2 is iodine, it can be 0.01 ≤ ε21 ≤ 0.3, and it can be 0.015 ≤ ε21 ≤ 0.1.

[0071] In formula (3), A, M, and Z are an alkali metal element, a tetravalent metal element or a metalloid element, and a halogen element, respectively. As specific examples, the above elements can be cited. M preferably contains Zr. X1 and D are a doping element X1 and a doping element X3, respectively. As specific examples, the above elements can be cited. It can be 1.5 ≤ α ≤ 3, it can be 1.8 ≤ α3 ≤ 2.5, it can be 1.9 ≤ α3 ≤ 2.3, it can be 1.95 ≤ α3 ≤ 2.2. It can be 0.5 ≤ β ≤ 2, it can be 0.7 ≤ β3 ≤ 1.4, it can be 0.8 ≤ β3 ≤ 1.2, it can be 0.9 ≤ β3 ≤ 1.1. It can be 0.005 ≤ ζ ≤ 0.5, it can be 0.01 ≤ ζ ≤ 0.2, it can be 0.02 ≤ ζ ≤ 0.15, it can be 0.025 ≤ ζ ≤ 0.10. It can be 3.5 ≤ δ3 ≤ 5, it can be 3.7 ≤ δ3 ≤ 4.3, it can be 3.8 ≤ δ3 ≤ 4.1. It can be 0.1 ≤ η ≤ 1.5, it can be 0.7 ≤ η ≤ 1.5, it can be 0.8 ≤ η ≤ 1.3, it can be 0.9 ≤ η ≤ 1.1.

[0072] As a method for manufacturing the solid electrolyte material, there is no particular limitation, but for example, a method including a step of ball-milling the raw materials can be cited. Annealing can also be performed on the product after ball-milling. In addition, in the case of obtaining a hexagonal solid electrolyte material, a method including a step of heating the raw materials under a pressure of 1 GPa or more can also be used.

[0073] There is no particular limitation on the raw materials. For example, a compound containing an alkali metal halide, a chloride of a metal element or a metalloid element other than an alkali metal, and a doping element X1 or X2 can be used. When the doping element is X1, the compound containing the doping element can be a halide of X1. When the doping element is X2, the compound containing the doping element can be an alkali metal bromide or an alkali metal iodide. The raw materials are preferably mixed before ball-milling, and more preferably mixed in an inert atmosphere (such as an Ar atmosphere).

[0074] There is no particular limitation on the conditions for ball-milling, but it can be set to 10 to 100 hours at a rotation speed of 200 to 700 rpm. The pulverization time is preferably 24 hours to 72 hours, and more preferably 36 to 60 hours.

[0075] There is no particular limitation on the balls used for ball-milling, but zirconia balls can be used. There is no particular limitation on the size of the balls used, but balls of 2 mm to 10 mm can be used.

[0076] By ball-milling for the above-mentioned time, the raw materials are sufficiently mixed, promoting the mechanochemical reaction, and thus the ionic conductivity of the obtained compound can be improved.

[0077] Annealing is preferably carried out in an inert atmosphere or in a vacuum. As the annealing temperature, for example, it is preferably 150 to 300 °C, more preferably 200 to 250 °C. As the annealing time, for example, it can be 1 to 10 hours, preferably 3 to 6 hours.

[0078] The ratio of the volume of the solid electrolyte material in the electrode material to the total volume of the solid electrolyte material and the ionic liquid can be 0.30 to 0.99, can be 0.50 to 0.99, can be 0.70 to 0.99, can be 0.80 to 0.99. The ratio of the volume of the solid electrolyte material in the electrode material to the total volume of the solid electrolyte material and the ionic liquid can be 0.30 to 0.90.

[0079] As the ionic liquid contained in the electrode material, there is no particular limitation as long as it is an ionic liquid containing an alkali metal ion as a cation. Such an ionic liquid can be a solvated ionic liquid. The ionic liquid can contain an alkali metal salt and an ether compound. The ether compound can be at least one of an acyclic ether compound and a cyclic ether compound. It should be noted that the cyclic ether compound is a compound having a ring structure containing at least one ether bond in the ring, and examples thereof include crown ethers. At least one or more of the hydrogen atoms bonded to the carbon atoms as ring members of the crown ether can also be substituted. The substituent can also be a monovalent substituent such as a halogen atom.

[0080] The ether compound can form a coordination bond with the alkali metal ion. That is, the battery material of the present embodiment can also contain a solid electrolyte, an alkali metal salt, and an ether compound. The solid electrolyte contains an alkali metal element, a metal element or a semi-metal element other than the alkali metal element, and a halogen element. At least a part of the ether compound forms a coordination bond with the alkali metal ion.

[0081] The acyclic ether compound is a compound that does not have a cyclic ether moiety and may have a ring structure other than the cyclic ether moiety. As the acyclic ether compound, diglyme can be cited. Diglyme can be a compound represented by the following chemical formula (B).

[0082] R 1 -(OCH 2 CH 2 ) n -OR 2 (B)

[0083] Wherein, R 1 and R 2 are each independently an alkyl group having 1 to 3 carbon atoms and can be a methyl group. n can be 1 to 8, can be 2 to 6, can be 3 or 4. The ionic liquid can contain one or two or more ether compounds. It should be noted that the ethylene glycol unit (OCH 2 CH2 At least one hydrogen atom of ( ) may also be substituted with a substituent. Examples of the substituent include monovalent substituents such as a halogen atom and an alkyl group having 1 to 3 carbon atoms.

[0084] The alkali metal salt is not particularly limited. Assuming the alkali metal is M, examples include MF, MCl, MBr, MI, MClO 4 , MPF 6 , MBF 4 , M 2 SO 4 , M[(C h F 2h+1 )SO 3 (h is 0 to 3), M[(C h F 2h+1 )SO 2 2 N (h is 0 to 3), etc. It can be at least one of M[FSO 2 2 N and [(CF 3 )SO 2 2 N. The ionic liquid may contain one or two or more alkali metal salts.

[0085] The molar ratio of the ether compound to the alkali metal ion in the ionic liquid ((ether compound):(alkali metal ion)) can be 1:0.8 to 1:1.2, can be 1:0.9 to 1:1.1, and can be 1:0.95 to 1:1.05.

[0086] The positive electrode active material is not particularly limited. For example, it includes an alkali metal composite oxide containing an alkali metal element and at least one metal element selected from the group consisting of transition metal elements and Al. The transition metal element can be at least one selected from the group consisting of V, Cr, Mn, Fe, Co, Ni, and Cu, and can include Ni. For example, when the alkali metal element is lithium (i.e., in the case of a lithium composite oxide), examples of the lithium composite oxide include LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , LiNi 0.5 Mn 1.5 O 4 , Li 2 MnO 3 , LiNi x Mn y Co 1-x-y O 2 [0 < x + y < 1]), LiNi x Co y Al​​​1-x-y O 2 [0 < x + y < 1]), LiCr 0.5 Mn 0.5 O 2 、LiFePO 4 、Li 2 FeP 2 O 7 、LiMnPO 4 、LiFeBO 3 、Li 3 V 2 (PO 4 ) 3 、Li 2 CuO 2 、Li 2 FeSiO 4 、Li 2 MnSiO 4 etc. When the positive electrode active material contains an alkali metal element other than Li, as a specific example thereof, a substance obtained by replacing Li in the above specific example with another alkali metal can be cited. As the alkali metal other than Li, Na or K can be cited.

[0087] In the solid electrolyte material, the ratio of the volume of the positive electrode active material to the total volume of the positive electrode active material and the solid electrolyte material can be 0.50 to 0.99, can be 0.60 to 0.99, and can be 0.80 to 0.99.

[0088] The positive electrode material may contain a positive electrode active material and, if necessary, a polymer electrolyte, a binder resin, a conductive aid, an organic solvent, an ionic liquid, etc.

[0089] The content of the positive electrode active material in the positive electrode material can be 50% by mass or more, can be 60% by mass or more, and can be 70% by mass or more with respect to the total amount of the positive electrode material. The content of the positive electrode active material in the positive electrode material can be 99% by mass or less, can be 95% by mass or less, and can be 90% by mass or less with respect to the total amount of the positive electrode material. In addition, the content of the positive electrode active material in the positive electrode material can be 50 to 99% by mass, can be 60 to 95% by mass, and can be 70 to 90% by mass with respect to the total amount of the positive electrode material.

[0090] The negative electrode material may contain a negative electrode active material and, if necessary, a polymer electrolyte, a binder resin, a conductive aid, an organic solvent, an ionic liquid, etc.

[0091] Examples of the negative electrode active material include elemental substances of alkali metal elements, Si, P, Sn, Si-Mn, Si-Co, Si-Ni, In, Au, etc., alloys or composites containing these elements, carbon materials such as graphite, substances obtained by intercalating alkali metal ions between the layers of the carbon material, and titanium-containing oxides. The alkali metal element can be Li, Na, or K, can be Li or Na, and can be Li.

[0092] Examples of the titanium-containing oxide can be a compound represented by the compositional formula: A s TiO t (where A is an alkali metal element and s≥0). Among them, the alkali metal element A can be Li, Na, or K, can be Li or Na, and can be Li.

[0093] The battery of this embodiment includes a positive electrode, a negative electrode, and an electrolyte disposed between the positive electrode and the negative electrode. At least one of the positive electrode, the negative electrode, and the electrolyte contains the battery material of this embodiment. The positive electrode can be a positive electrode having a layer containing a positive electrode material formed on a current collector. In addition, the negative electrode can be a negative electrode having a layer containing a negative electrode material formed on a current collector. Examples of the battery include batteries that charge and discharge by the movement of alkali metal ions such as lithium ion batteries and sodium ion batteries. The battery can be a primary battery, a secondary battery, or an all-solid-state battery.

[0094] The battery material of this embodiment may further contain a binder resin (binder, binding polymer), a conductive additive, etc. There is no particular limitation on the binder resin, but examples thereof include fluorine-based resins and acrylic resins. As the fluorine-based resin, a resin having a carbon chain as the main chain is preferred. The carbon chain can be a carbon chain formed by radical polymerization of an ethylenically unsaturated group. Examples of the fluororesin include poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyvinylidene fluoride (PVDF), etc. The content of the binder resin in the electrode material can be 0.5 to 10% by mass, and can be 1 to 7% by mass. The fluorine-based resin and the acrylic resin can also be resins having a fibrillating property.

[0095] Examples of the conductive additive include carbon materials such as natural graphite (flaky graphite, etc.), artificial graphite; carbon blacks such as acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal cracking carbon black; carbon fibers; etc. The content of the conductive additive in the electrode material can be 0.5 to 10% by mass, and can be 1 to 7% by mass.

[0096] The battery material (battery component) of this embodiment can be a material obtained by coating an ionic liquid on the surface of a composition containing the above-mentioned solid electrolyte material after forming the composition (this coating is also referred to as the second layer). The composition can be a shaped body or a layer (the first layer). If the composition is a composition containing materials other than the ionic liquid, the effects of the present disclosure can be more effectively exerted. The ionic liquid can be coated, for example, as a mixture with other components such as a binder resin (composition containing the ionic liquid). In addition, the ionic liquid can also be further coated on the surface of the battery material. The above composition can further contain polymers such as the above-mentioned binder polymer. The battery component can be a laminate. In addition, the battery material can also contain ionic liquids other than the above-mentioned ionic liquid (ionic liquid containing an alkali metal ion as a cation) (other ionic liquids) within the range that does not hinder the effects of this embodiment. Examples of other ionic liquids include ionic liquids having an organic cation as a cation. The content of other ionic liquids can be set to 5% by mass, 1% by mass or less, or 0.1% by mass or less relative to the total amount of the battery material. The first layer can be any one of a positive electrode layer, a negative electrode layer, and a solid electrolyte layer, or can be a solid electrolyte layer. The positive electrode layer can contain a positive electrode active material, a solid electrolyte material, and optionally a binder resin, a conductive additive, etc. The negative electrode layer can contain a negative electrode active material, a solid electrolyte material, and optionally a binder resin, a conductive additive, etc. The solid electrolyte layer can contain a solid electrolyte material and optionally a binder resin, a conductive additive, etc.

[0097] The battery can also have a separator. As the separator, it can be a porous material and can be a resinous porous material. Specifically, porous polyolefin membranes, porous ceramic membranes, etc. can be cited.

[0098] Examples

[0099] (Manufacturing Example 1 of Ionic Liquid)

[0100] Mix tetraethylene glycol dimethyl ether (hereinafter, also referred to as G4) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in a ratio of 50:50 to manufacture an ionic liquid (G4 + LiTFSI).

[0101] (Manufacturing Example 2 of Ionic Liquid)

[0102] Mix tetraethylene glycol dimethyl ether (hereinafter, also referred to as G4) and lithium bis(fluorosulfonyl)imide (LiFSI) in a ratio of 50:50 to manufacture an ionic liquid (G4 + LiFSI).

[0103] (Manufacturing Example 1 of Solid Electrolyte Material)

[0104] · Ball milling

[0105] In an argon atmosphere with a dew point below -70 °C (hereinafter referred to as a dry argon atmosphere), LiCl and InCl 3 were mixed at a molar ratio of 3:1 to prepare the raw materials.

[0106] 1.2 g of the above raw materials were added to a zirconia mortar with a volume of 50 ml, and 65 g of zirconia balls with a diameter of 4 mm were put in. By using a planetary ball mill (manufactured by Verder Scientific Co., Ltd., PM 400) and treating under the conditions of 48 hours and 380 rpm in a manner of performing a mechanochemical reaction, the crude composition of Production Example 1 was obtained.

[0107] · Annealing

[0108] For the crude composition of Example 1 obtained above, by heating in a dry argon atmosphere at 230 °C for 5 hours, a solid electrolyte material of Production Example 1 having a feed composition of Li 3 InCl 6 was obtained.

[0109] (Production Example 2 of solid electrolyte material)

[0110] In a dry argon atmosphere with a dew point below -70 °C, Li 2 О, ZrCl 4 and Li 3 PО 4 were mixed at a molar ratio of 1:1:0.033 to prepare the raw materials.

[0111] 1.2 g of the above raw materials were placed in a zirconia mortar with a volume of 50 ml, and 65 g of zirconia balls with a diameter of 4 mm were put in. By using the above planetary ball mill and treating under the conditions of 24 hours and 300 rpm in a manner of performing a mechanochemical reaction, a solid electrolyte material having a feed composition of Li 2.1 ZrCl 4 O(PO 4 ) 0.033 was obtained.

[0112] The ball milling was carried out in a mode of stopping for 1 minute every 10 minutes of rotation and alternately switching the rotation direction between clockwise and counterclockwise.

[0113] (Production Example 3 of solid electrolyte material)

[0114] In Production Example 1 of the above solid electrolyte material, using LiCl, InCl 3 and ZrCl 4 , so that the feed composition becomes Li 2.89 In 0.91 Zr 0.096 Cl6 It is carried out in the following manner. In addition, the solid electrolyte material of Production Example 3 is obtained by the same method.

[0115] <Manufacture of Battery Materials>

[0116] (Examples 1 to 4 and Comparative Examples 1 to 3)

[0117] As shown in Table 1, the solid electrolyte material is mixed with a softening component (ionic liquid or organic solvent) to obtain a battery material. The content of the solid electrolyte material is the content of the solid electrolyte material relative to the total amount (total mass or total volume) of the solid electrolyte material and the softening component.

[0118] It should be noted that the meanings of the abbreviations in Table 1 are as follows.

[0119] · Pyrr14FSI: 1-Butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide

[0120] · EC / PC: A mixed solvent with a volume ratio of ethylene carbonate to propylene carbonate of 1:1

[0121] · DMF: Dimethylformamide

[0122] <Powder X-ray Diffraction>

[0123] For the obtained battery material, powder X-ray diffraction measurement is carried out at 25°C. The measurement conditions for the powder X-ray diffraction measurement are implemented according to the following conditions.

[0124] Measurement device: Ultima IV (manufactured by Rigaku Corporation)

[0125] X-ray generator: CuKα ray source voltage 40 kV, current 40 mA

[0126] X-ray detector: Scintillation counter or semiconductor detector

[0127] Measurement range: Diffraction angle 2θ = 5° to 80°

[0128] Scanning speed: 4° / minute

[0129] Figure 1 It is a figure showing the X-ray diffraction patterns obtained for the battery materials of Example 1, Example 2, and Comparative Example 1.

[0130] The half-value width of the peak is obtained by removing the background signal and performing fitting.

[0131] <Measurement of Ionic Conductivity>

[0132] Prepare a compression molding die having a frame, a lower punch, and an upper punch. It should be noted that the frame is formed of insulating polycarbonate. In addition, both the upper punch and the lower punch are formed of electroconductive stainless steel and are electrically connected to the terminals of an impedance analyzer (Sl1260 manufactured by Solatron Analytical) respectively.

[0133] Using the above compression molding die, measure the ionic conductivity of the battery material by the following method. First, in a dry argon atmosphere, fill the battery material onto the lower punch inserted vertically downward into the hollow portion of the frame. Then, by pressing the upper punch downward into the hollow portion of the frame, a pressure of 370 MPa is applied to the battery material inside the compression molding die. After applying the pressure, fasten and fix the punch from above and below with a clamp, and in a state of maintaining a constant pressure, use the above impedance analyzer to measure the impedance of the battery material by electrochemical impedance measurement.

[0134] Based on the impedance measurement results, make a chart of the Cole-Cole plot. In the Cole-Cole plot, regard the real value of the impedance at the measurement point where the absolute value of the phase of the complex impedance is the smallest as the resistance value of the ionic conductive substance with respect to ionic conduction. Using this resistance value, calculate the ionic conductivity based on the following mathematical formula (III). The results are shown in Table 1.

[0135] σ=(RSE×S / t) -1 (III)

[0136] Wherein,

[0137] σ is the ionic conductivity,

[0138] S is the contact area of the ionic conductive substance with the upper punch (equal to the cross-sectional area of the hollow portion of the frame),

[0139] RSE is the resistance value of the battery material in the impedance measurement,

[0140] t is the thickness of the battery material when applying the pressure.

[0141] Measure the ionic conductivity of each battery material of the examples and comparative examples at 25 °C. The results are shown in Table 1.

[0142] In addition, as Figure 2 shown, for the battery material of Example 1, measure the ionic conductivity in the same manner at each temperature of 80 °C, 60 °C, 40 °C, 25 °C, 10 °C, -5 °C, -20 °C, and -35 °C, make a chart of the ionic conductivity (σ) versus 1000 / T (T is the absolute temperature), and obtain the activation energy.

[0143] [Table 1]

[0144]

[0145] Figure 3 The X-ray diffraction pattern of Comparative Example 1 is shown. The upper figure is the actually measured X-ray diffraction pattern. The middle figure is the X-ray diffraction pattern of LiCl based on theoretical calculation. The lower figure is the X-ray diffraction pattern of Li 3 InCl 6 as is known from Figure 3 It can be seen that the solid electrolyte material is decomposed to produce LiCl. It should be noted that the decomposition (LiCl) in Table 1 indicates that the diffraction peak of LiCl is observed and the decomposition is confirmed. In Examples 1 to 4, the diffraction peak derived from LiCl was not confirmed.

[0146] (Measurement of impedance)

[0147] Weigh 0.27 g of the solid electrolyte material Li 2.89 In 0.91 Zr 0.096 Cl 6 obtained in "Production Example 3 of Solid Electrolyte Material" and 0.03 g of polytetrafluoroethylene (PTFE, manufactured by Chemours-Mitsui Fluoroproducts Co., Ltd., fine powder 6-J), and mix them by hand grinding using an agate mortar to obtain a granular electrolyte composition.

[0148] For the obtained granular electrolyte composition, collect 0.10 g and stretch it in a circular shape with a diameter of 17.5 mm in a uniform manner to obtain a sheet-like electrolyte composition.

[0149] Respectively, for the upper and lower surfaces of the obtained sheet-like electrolyte composition, collect 10 μl of the ionic liquid obtained in "Production Example 2 of Ionic Liquid" using a pipette and drop it, thereby forming a coating layer on the upper and lower surfaces of the sheet-like electrolyte composition to obtain a laminate.

[0150] By attaching 2 mg of thinly stretched Li foil to the upper and lower surfaces of the coating layer of the obtained laminate respectively, a symmetric cell is fabricated (the layer structure is expressed as Li / IL / SE / IL / Li. IL: ionic liquid, SE: solid electrolyte (electrolyte composition)).

[0151] For the solid electrolyte layer in this symmetric cell, no decomposition behavior was observed.

[0152] In addition, as a comparison object, a symmetric cell was fabricated without forming a coating layer of ionic liquid (the layer structure is expressed as Li / SE / Li).

[0153] The impedance of these symmetric cells was measured using an impedance analyzer (Sl1260 manufactured by Solatron Analytical). The results are shown in Figure 4 . As Figure 4 shown in, it was confirmed that the resistivity decreased compared to the case without the coating of the ionic liquid (G4+LiFSI).

[0154] From this, it was found that the interfacial resistance can be reduced by fabricating a laminate structure.

[0155] The resistivity of each symmetric cell is as follows.

[0156] Resistivity of Li / IL / SE / IL / Li: 3.8×10 5 Ωcm

[0157] Resistivity of Li / SE / Li: 5.0×10 5 Ωcm

Claims

1. A battery material, which comprises a solid electrolyte material and an ionic liquid, wherein the solid electrolyte material contains an alkali metal element, a metal element or a metalloid element other than the alkali metal element, and a halogen element, and the ionic liquid contains an alkali metal ion as a cation.

2. The battery material according to claim 1, wherein, it further comprises a positive electrode active material.

3. The battery material according to claim 1 or 2, wherein, The solid electrolyte material contains A α M β Z γ D ζ O η compound represented by, in the formula, A is an alkali metal element, M is a metal element or a metalloid element other than the alkali metal element, Z is a halogen element, D is at least one of P and S, 1.6 ≤ α ≤ 3.5, 0 < β ≤ 1.2, 3 ≤ γ ≤ 6.5, 0 ≤ ζ ≤ 0.5, 0 ≤ η ≤ 2.

4. The battery material according to claim 1 or 2, wherein, the ratio of the volume of the solid electrolyte material to the total volume of the solid electrolyte material and the ionic liquid is 0.30 to 0.

90.

5. The battery material according to claim 2, wherein, the ratio of the volume of the positive electrode active material to the total volume of the positive electrode active material and the solid electrolyte material is 0.50 to 0.

99.

6. The battery material according to claim 1 or 2, wherein, it further comprises a binder polymer.

7. The battery material according to claim 2, wherein, the positive electrode active material is a lithium-containing composite oxide containing nickel.

8. A battery component, which is a laminate having a first layer and a second layer laminated on the first layer, the first layer contains a solid electrolyte material, and the second layer contains an ionic liquid containing an alkali metal ion as a cation.

9. The battery component according to claim 8, wherein, the first layer contains a polymer.

10. A positive electrode, wherein, it contains the battery material according to claim 2.

11. A battery, which comprises the positive electrode according to claim 10.

12. A battery material, wherein, it comprises a solid electrolyte material, an alkali metal salt and an ether compound, the solid electrolyte material contains an alkali metal element, a metal element or a metalloid element other than the alkali metal element, and a halogen element, and at least a part of the ether compound is coordinated with the alkali metal ion.

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