Electrodes and batteries

Abstract

The electrode (1000) of the present disclosure includes an electrode mixture layer (110) and an electrode current collector layer (100). The electrode current collector layer (100) is in contact with the electrode mixture layer (110). The electrode mixture layer (110) includes a solid electrolyte material (111) and an active material (112). The solid electrolyte material (111) includes Li, M, and X. M is at least one selected from metal elements other than Li and semi-metal elements. X is at least one selected from F, Cl, Br, and I. In the electrode current collector layer (100), the copper content in the surface material in contact with the electrode mixture layer (110) is less than 50 mass%.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an electrode and a battery. BACKGROUND

[0002] A positive electrode and a battery including a halide solid electrolyte, a positive electrode active material, and a positive electrode current collector are disclosed in Patent Literature 1. For the positive electrode current collector, aluminum powder is used.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: International Publication No. 2019 / 146217 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The present disclosure provides an electrode that improves the cycle characteristics of a battery.

[0008] MEANS FOR SOLVING THE PROBLEMS

[0009] The electrode in one aspect of the present disclosure has:

[0010] an electrode current collector layer,

[0011] an electrode current collector layer,

[0012] wherein the electrode current collector layer is in contact with the electrode mixture layer,

[0013] the electrode mixture layer contains a solid electrolyte material and an active material,

[0014] the solid electrolyte material contains Li, M, and X,

[0015] M is at least one selected from metal elements other than Li and semimetal elements,

[0016] X is at least one selected from F, Cl, Br, and I,

[0017] In the electrode current collector layer, the copper content in the surface material in contact with the electrode mixture layer is less than 50 mass%.

[0018] EFFECT OF THE INVENTION

[0019] The present disclosure provides an electrode that improves the cycle characteristics of a battery. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A cross-sectional view of the electrode 1000 of Embodiment 1 is shown.

[0021] Figure 2A cross-sectional view of a battery 2000 according to Embodiment 2. DETAILED DESCRIPTION

[0022] The electrode according to the first aspect of the present disclosure includes:

[0023] the electrode mixture layer, and

[0024] the electrode current collector layer,

[0025] wherein the electrode current collector layer is in contact with the electrode mixture layer,

[0026] the electrode mixture layer includes a solid electrolyte material and an active material,

[0027] the solid electrolyte material includes Li, M, and X,

[0028] the M is at least one selected from metal elements other than Li and semi-metal elements,

[0029] the X is at least one selected from F, Cl, Br, and I,

[0030] in the electrode current collector layer, a copper content in a surface material in contact with the electrode mixture layer is less than 50 mass%.

[0031] The electrode according to the first aspect, when used in a battery, can improve a cycle characteristic of the battery.

[0032] In the second aspect of the present disclosure, for example, in the electrode according to the first aspect, the copper content in the surface material can also be 4.5 mass% or less.

[0033] The electrode according to the second aspect, when used in a battery, can further improve a cycle characteristic of the battery.

[0034] In the third aspect of the present disclosure, for example, in the electrode according to the first aspect or the second aspect, the solid electrolyte material can also be represented by the following composition formula (1).

[0035] Li α M β X γ Formula (1)

[0036] wherein the a, the b, and the g are all values greater than 0.

[0037] According to the electrode according to the third aspect, the ionic conductivity of the solid electrolyte material is improved, and thus the ionic conductivity of the electrode can be improved. Thus, the electrode according to the third aspect, when used in a battery, can further improve a cycle characteristic of the battery.

[0038] In the fourth aspect of the present disclosure, the M in the electrode of any one of the first to third aspects may also include yttrium.

[0039] The electrode of the fourth aspect, when used in a battery, can further improve the cycle characteristics of the battery.

[0040] In the fifth aspect of the present disclosure, the electrode current collector layer in the electrode of any one of the first to fourth aspects may also include aluminum as a main component.

[0041] In the sixth aspect of the present disclosure, the electrode current collector layer in the electrode of the fifth aspect may also further include an element other than aluminum.

[0042] In the seventh aspect of the present disclosure, the electrode current collector layer in the electrode of any one of the first to sixth aspects may also include an aluminum alloy.

[0043] Aluminum and aluminum alloys are lightweight metals with high electrical conductivity. Therefore, the electrode of the fifth to seventh aspects, when used in a battery, can not only improve the cycle characteristics of the battery, but also further improve the weight energy density of the battery.

[0044] In the eighth aspect of the present disclosure, the active material in the electrode of any one of the first to seventh aspects may also be a lithium-containing transition metal oxide.

[0045] The electrode of the eighth aspect, when used in a battery, can not only improve the cycle characteristics of the battery, but also further reduce the manufacturing cost of the electrode and the battery, and improve the average discharge voltage of the battery.

[0046] In the ninth aspect of the present disclosure, the active material in the electrode of the eighth aspect may also be lithium nickel cobalt manganese oxide.

[0047] The electrode of the ninth aspect, when used in a battery, can not only improve the cycle characteristics of the battery, but also improve the energy density of the battery.

[0048] The battery of the tenth aspect of the present disclosure has:

[0049] a positive electrode,

[0050] a negative electrode, and

[0051] an electrolyte layer disposed between the positive electrode and the negative electrode,

[0052] wherein at least one selected from the positive electrode and the negative electrode is the electrode of any one of the first to ninth aspects.

[0053] According to the battery of the tenth aspect, excellent cycle characteristics can be achieved.

[0054] In the 11th aspect of the present disclosure, the positive electrode described above can also be any one of the electrodes of the 1st to 9th aspects, for example, in the battery of the 10th aspect.

[0055] According to the battery of the 11th aspect, more excellent cycle characteristics can be achieved.

[0056] Hereinafter, the embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0057] (Embodiment 1)

[0058] Figure 1 A cross-sectional view of the electrode 1000 of Embodiment 1 is shown. The electrode 1000 of Embodiment 1 includes an electrode current collector layer 100 and an electrode mixture layer 110. The electrode current collector layer 100 is in contact with the electrode mixture layer 110. The electrode mixture layer 110 includes a solid electrolyte material 111 and an active material 112. The solid electrolyte material 111 includes Li, M, and X. Here, M is at least one selected from metal elements other than Li and semi-metal elements, and X is at least one selected from F, Cl, Br, and I. The copper content in the surface material of the electrode current collector layer 100 in contact with the electrode mixture layer 110 is less than 50 mass%.

[0059] With the above configuration, the electrode 1000 of Embodiment 1, when used in a battery (for example, a full-solid secondary battery), can improve the cycle characteristics of the battery.

[0060] In the electrode current collector layer 100 of Embodiment 1, the copper content in the surface material described above can also be 4.5 mass% or less.

[0061] With the above configuration, the electrode 1000 of Embodiment 1, when used in a battery, can further improve the cycle characteristics of the battery.

[0062] In the electrode current collector layer 100, the so-called "surface material of the electrode current collector layer 100 in contact with the electrode mixture layer 110" refers to the material of the electrode current collector layer 100 from the surface to a depth of 50 nm of the portion of the surface of the electrode current collector layer 100 in contact with the electrode mixture layer 110. The copper content in the surface material is the proportion of the mass of copper contained in the surface material with respect to the total mass of the surface material. The copper content in the surface material can be obtained, for example, by scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX). In cases where it is difficult to measure by SEM-EDX, the copper content in the surface material can also be obtained, for example, by X-ray photoelectron spectroscopy (XPS).

[0063] In the present disclosure, the "semi-metal elements" are B, Si, Ge, As, Sb, and Te.

[0064] Further, in the present disclosure, a "metal element" is an element described below:

[0065] (i) all elements contained in Groups 1 to 12 of the periodic table, except hydrogen, and

[0066] (ii) all elements contained in Groups 13 to 16 of the periodic table, except B, Si, Ge, As, Sb, Te, C, N, P, O, S, and Se.

[0067] That is, in the present disclosure, a "semimetal element" and a "metal element" are groups of elements that can become cations when forming inorganic compounds with halogen elements.

[0068] Hereinafter, the electrode 1000 of Embodiment 1 will be described in detail. The solid electrolyte material 111 can also be a halide solid electrolyte material. Note that the "halide solid electrolyte material" in the present disclosure refers to a solid electrolyte material that contains halogen elements and does not contain sulfur. Further, in the present disclosure, the "solid electrolyte material not containing sulfur" refers to a solid electrolyte material expressed by a composition formula not containing sulfur elements. Therefore, a solid electrolyte material containing a trace amount of sulfur components, such as sulfur of 0.1% by mass or less, is included in the solid electrolyte material not containing sulfur. The halide solid electrolyte material can further contain oxygen as an anion other than halogen elements. Hereinafter, an example in which the solid electrolyte material 111 is a halide solid electrolyte material containing Li, M, and X will be described. Therefore, the solid electrolyte material 111 is sometimes referred to as the halide solid electrolyte material 111.

[0069] [Electrode mixture layer]

[0070] The electrode mixture layer 110 in Embodiment 1 contains the halide solid electrolyte material 111 and the active material 112. Hereinafter, the halide solid electrolyte material 111, the active material 112, and the electrode mixture layer 110 will be described in detail.

[0071] [Halide solid electrolyte material]

[0072] As described above, the halide solid electrolyte material 111 is a material containing Li, M, and X. The element M and the element X are as described above. According to the above configuration, the ionic conductivity of the halide solid electrolyte material 111 is further improved, and thus the ionic conductivity of the electrode in Embodiment 1 can be further improved. Thus, the electrode in Embodiment 1, when used in a battery, can improve the cycle characteristics of the battery. Further, the electrode in Embodiment 1, when used in a battery, can improve the thermal stability of the battery. Further, the halide solid electrolyte material 111 does not contain sulfur, and thus the electrode in Embodiment 1 can suppress the generation of hydrogen sulfide gas.

[0073] The halide solid electrolyte material 111 can also be a material represented by the following composition formula (1).

[0074] Li α M β X γ Formula (1)

[0075] In the above composition formula (1), a, b, and g are values greater than 0. g can be, for example, 4 or 6.

[0076] According to the above configuration, the ionic conductivity of the halide solid electrolyte material 111 is improved, and thus the ionic conductivity of the electrode in Embodiment 1 can be improved. As a result, the electrode 1000 in Embodiment 1, when used in a battery, can further improve the cycle characteristics of the battery.

[0077] In the above composition formula (1), the element M can also include Y (= yttrium). That is, the halide solid electrolyte material 111 can also include Y as a metal element.

[0078] The halide solid electrolyte material 111 including Y can also be represented by the following composition formula (2), for example.

[0079] Li a Me b Y c X6 Formula (2)

[0080] In the above composition formula (2), a, b, and c can also satisfy a + mb + 3c = 6 and c > 0. The element Me is at least one selected from metal elements and semi-metal elements other than Li and Y. m represents the valence number of the element Me. Note that in the case where the element Me includes multiple elements, mb becomes the sum of the values obtained by multiplying the composition ratio of each element by the valence number of the element. For example, in the case where Me includes an element Me1 and an element Me2, the composition ratio of the element Me1 is b1, the valence number of the element Me1 is m1, the composition ratio of the element Me2 is b2, and the valence number of the element Me2 is m2, mb = m1b1 + m2b2. In the above composition formula (2), the element X is at least one selected from F, Cl, Br, and I.

[0081] The element Me can also be at least one selected from Mg, Ca, Sr, Ba, Zn, Sc, Al, Ga, Bi, Zr, Hf, Ti, Sn, Ta, Gd, and Nb, for example.

[0082] As the halide solid electrolyte material 111, for example, the following material can be used. According to the following material, the ionic conductivity of the halide solid electrolyte material 111 is further improved, and thus the ion conductivity of the electrode 1000 in Embodiment 1 can be further improved. Thus, the electrode 1000 in Embodiment 1, when used in a battery, can further improve the cycle characteristics of the battery.

[0083] The halide solid electrolyte material 111 can also be a material represented by the following composition formula (A1).

[0084] Li 6-3d Y d X6 Formula (A1)

[0085] In the composition formula (A1), the element X is at least one selected from Cl, Br, and I. Further, in the composition formula (A1), d satisfies 0 < d < 2.

[0086] The halide solid electrolyte material 111 can also be a material represented by the following composition formula (A2).

[0087] Li3YX6 Formula (A2)

[0088] In the composition formula (A2), the element X is at least one selected from Cl, Br, and I.

[0089] The halide solid electrolyte material 111 can also be a material represented by the following composition formula (A3).

[0090] Li 3-3δ Y 1+δ Cl6 Formula (A3)

[0091] In the composition formula (A3), δ satisfies 0 < δ ≤ 0.15.

[0092] The halide solid electrolyte material 111 can also be a material represented by the following composition formula (A4).

[0093] Li 3-3δ Y 1+δ Br6 Formula (A4)

[0094] In the composition formula (A4), δ satisfies 0 < δ ≤ 0.25.

[0095] The halide solid electrolyte material 111 can also be a material represented by the following composition formula (A5).

[0096] Li 3-3δ+a Y 1+δ-a Me a Cl 6-x-y Brx I y Formula (A5)

[0097] where, in the composition formula (A5), the element Me is at least one selected from the group consisting of Mg, Ca, Sr, Ba, and Zn.

[0098] Further, the above composition formula (A5) satisfies:

[0099] -1 < δ < 2,

[0100] 0 < a < 3,

[0101] 0 < (3 - 3δ + a),

[0102] 0 < (1 + δ - a),

[0103] 0 ≤ x ≤ 6,

[0104] 0 ≤ y ≤ 6, and

[0105] (x + y) ≤ 6.

[0106] The halide solid electrolyte material 111 can also be a material represented by the following composition formula (A6).

[0107] Li 3-3δ Y 1+δ-a Me a Cl 6-x-y Br x I y Formula (A6)

[0108] where, in the above composition formula (A6), the element Me is at least one selected from the group consisting of Al, Sc, Ga, and Bi.

[0109] Further, the above composition formula (A6) satisfies:

[0110] -1 < δ < 1,

[0111] 0 < a < 2,

[0112] 0 < (1 + δ - a),

[0113] 0 ≤ x ≤ 6,

[0114] 0 ≤ y ≤ 6, and

[0115] (x + y) ≤ 6.

[0116] The halide solid electrolyte material 111 can also be a material represented by the following composition formula (A7).

[0117] Li 3-3δ-a Y 1+δ-a Me a Cl6-x-y Br x I y Formula (A7)

[0118] where, in the above composition formula (A7), the element Me is at least one selected from the group consisting of Zr, Hf, and Ti.

[0119] Further, the above composition formula (A7) satisfies:

[0120] -1 < δ < 1,

[0121] 0 < a < 1.5,

[0122] 0 < (3 - 3δ - a),

[0123] 0 < (1 + δ - a),

[0124] 0 ≤ x ≤ 6,

[0125] 0 ≤ y ≤ 6, and

[0126] (x + y) ≤ 6.

[0127] The halide solid electrolyte material 111 can also be a material represented by the following composition formula (A8).

[0128] Li 3-3δ-2a Y 1+δ-a Me a Cl 6-x-y Br x I y Formula (A8)

[0129] where, in the above composition formula (A8), the element Me is at least one selected from the group consisting of Ta and Nb.

[0130] Further, the above composition formula (A8) satisfies:

[0131] -1 < δ < 1,

[0132] 0 < a < 1.2,

[0133] 0 < (3 - 3δ - 2a),

[0134] 0 < (1 + δ - a),

[0135] 0 ≤ x ≤ 6,

[0136] 0 ≤ y ≤ 6, and

[0137] (x + y) ≤ 6.

[0138] As the halide solid electrolyte material 111, more specifically, for example, Li3YX6, Li2MgX4, Li2FeX4, Li(Al, Ga, In)X4, Li3(Al, Ga, In)X6, or the like can be used. Among these, in these materials, the element X is at least one selected from F, Cl, Br, and I. Note that in the present disclosure, when an element in a formula is expressed as "(Al, Ga, In)", this indicates at least one element selected from the group of elements within the parentheses. That is, "(Al, Ga, In)" and "at least one selected from Al, Ga, and In" have the same meaning. The same applies to other elements.

[0139] Further, the shape of the halide solid electrolyte material 111 is not particularly limited, and for example, it can be needle-shaped, spherical, oval spherical, or the like. For example, the shape of the halide solid electrolyte material 111 can also be particulate.

[0140] Next, a method for manufacturing the halide solid electrolyte material 111 will be described. Here, a method for manufacturing the halide solid electrolyte material represented by the above composition formula (1) will be exemplified.

[0141] First, according to the target composition, for example, a plurality of raw material powders of binary halides are prepared. A binary halide refers to a compound formed of two elements including a halogen element. For example, in the case of producing Li3YCl6, raw material powder LiCl and raw material powder YCl3 are prepared in a molar ratio of 3: 1. At this time, by selecting the types of the raw material powders, the element types of "M" and "X" in the composition formula (1) can be determined. Further, by adjusting the types of the raw material powders, the mixing ratio of the raw material powders, and the synthesis process, the values of "α", "β", and "γ" in the composition formula (1) can be adjusted.

[0142] After the raw material powders are mixed and pulverized, the raw material powders are caused to react with each other using a method of mechanical chemical polishing. Alternatively, after the raw material powders are mixed and pulverized, sintering can be performed in a vacuum or an inert atmosphere. The firing conditions can be, for example, firing at 100°C to 550°C for one hour or more. By these methods, the halide solid electrolyte material represented by the above composition formula (1) can be obtained.

[0143] Note that the crystal phase structure (i.e., crystal structure) of the halide solid electrolyte material can be adjusted or determined by the method of reaction of the raw material powders with each other and the reaction conditions.

[0144] <Active material>

[0145] The active material 112 in Embodiment 1 is a positive electrode active material or a negative electrode active material.

[0146] The positive electrode active material is, for example, a material having the property of intercalating and deintercalating metal ions (e.g., lithium ions). Examples of the positive electrode active material are a lithium-containing transition metal oxide, a transition metal fluoride, a polyanion material, a fluorinated polyanion material, a transition metal sulfide, a transition metal oxysulfide, or a transition metal oxynitride. Examples of the lithium-containing transition metal oxide are Li(Ni, Co, Al)O2, Li(Ni, Co, Mn)O2, or LiCoO2. As the positive electrode active material, for example, in the case of using a lithium-containing transition metal oxide, it is possible to reduce the manufacturing cost of the electrode 1000 and the battery, and to increase the average discharge voltage of the battery.

[0147] Further, in order to increase the energy density of the battery, as the positive electrode active material, lithium nickel cobalt manganese oxide can also be used. For example, the positive electrode active material can be Li(Ni, Co, Mn)O2.

[0148] The negative electrode active material is, for example, a material having the property of intercalating and deintercalating metal ions (e.g., lithium ions). Examples of the negative electrode active material are a metal material, a carbon material, an oxide, a nitride, a tin compound, or a silicon compound. The metal material can be a simple substance metal or an alloy. Examples of the metal material are lithium metal or a lithium alloy. Examples of the carbon material are natural graphite, coke, carbon in the process of graphitization, carbon fiber, spherical carbon, artificial graphite, or amorphous carbon. By using silicon (Si), tin (Sn), a silicon compound, or a tin compound, it is possible to increase the capacity density of the battery.

[0149] <electrode mixture layer>

[0150] The electrode mixture layer 110 contains the halide solid electrolyte material 111 as described above. According to this configuration, the ion conductivity in the inside of the electrode mixture layer 110 becomes high, and becomes able to operate at a high output power.

[0151] In the case where the halide solid electrolyte material 111 contained in the electrode mixture layer 110 has a particle shape (e.g., a spherical shape), the median particle diameter of the halide solid electrolyte material 111 can also be 100 μm or less. In the case where the median particle diameter of the halide solid electrolyte material 111 is 100 μm or less, the active material 112 and the halide solid electrolyte material 111 can be well dispersed in the electrode mixture layer 110. Thereby, the charge and discharge characteristics of the battery are improved.

[0152] The median particle diameter of the halide solid electrolyte material 111 contained in the electrode mixture layer 110 can also be smaller than the median particle diameter of the active material 112. Thereby, the halide solid electrolyte material 111 and the active material 112 can be well dispersed.

[0153] The median particle diameter of the active material 112 can also be 0.1 μm to 100 μm. In the case where the median particle diameter of the active material is 0.1 μm or more, the active material 112 and the halide solid electrolyte material 111 can be well dispersed in the electrode mixture layer 110. As a result, the charge-discharge characteristics of a battery using the electrode 1000 are improved. In the case where the median particle diameter of the active material 112 is 100 μm or less, the lithium diffusion speed within the active material is improved. Therefore, a battery using the electrode 1000 can operate at a high output power.

[0154] The median particle diameter is the particle diameter at which the cumulative volume in the particle size distribution based on volume is 50%. The particle size distribution based on volume is found by a laser diffraction scattering method. The same applies to other materials described below.

[0155] When the volume fraction of the active material 112 and the halide solid electrolyte material 111 contained in the electrode mixture layer 110 is set to "v1: 100-v1", 30 ≤ v1 ≤ 95 can also be satisfied. Here, v1 represents the volume fraction of the active material 112 when the total volume of the active material 112 and the solid electrolyte material 111 contained in the electrode mixture layer 110 is set to 100. In the case where 30 ≤ v1 is satisfied, it is easy to ensure sufficient energy density of the battery. In the case where v1 ≤ 95 is satisfied, it becomes easier for the battery to operate at a high output power.

[0156] The thickness of the electrode mixture layer 110 can also be 10 μm to 500 μm. In the case where the thickness of the electrode mixture layer 110 is 10 μm or more, it becomes easy to ensure sufficient energy density of the battery. In the case where the thickness of the electrode mixture layer 110 is 500 μm or less, it becomes easier for the battery to operate at a high output power.

[0157] In order to reduce the interface resistance with the halide solid electrolyte material 111, the active material 112 can also be covered with a covering material. As the covering material, a material having low electronic conductivity can be used. As the covering material, an oxide material and an oxide solid electrolyte material, etc. can be used.

[0158] As the oxide material used in the covering material, for example, SiO2, Al2O3, TiO2, B2O3, Nb2O5, WO3, and ZrO2, etc. can be used.

[0159] As the oxide solid electrolyte material used in the covering material, for example, a Li-Nb-O compound such as LiNbO3, a Li-B-O compound such as LiBO2 and Li3BO3, a Li-Al-O compound such as LiAlO2, a Li-Si-O compound such as Li4SiO4, a Li-S-O compound such as Li2SO4, a Li-Ti-O compound such as Li4Ti5O12, a Li-Ge-O compound such as Li4GeO4, a Li-Sn-O compound such as Li4SnO4, a Li-Fe-O compound such as Li2FeO3, a Li-Co-O compound such as Li2CoO2, a Li-Mn-O compound such as Li2MnO3, a Li-12 Li-Ti-O compounds, Li2Zr03, Li-Zr-O compounds, Li2Mo03, Li-Mo-O compounds, LiV205, Li-V-O compounds, Li2WO4, Li-W-O compounds, and the like. Oxide solid electrolyte materials have high ionic conductivity and high high-potential stability. Therefore, by using an oxide solid electrolyte material as a covering material, the charge-discharge efficiency of a battery can be further improved.

[0160] [Electrode current collector layer]

[0161] Patent Document 1 discloses a positive electrode and a battery including a halide solid electrolyte, an active material, and a positive electrode current collector. In the battery disclosed in Patent Document 1, aluminum powder is used for the positive electrode current collector. That is, the positive electrode disclosed in Patent Document 1 includes a halide solid electrolyte, an active material, and an aluminum current collector. According to Patent Document 1, the positive electrode disclosed in Patent Document 1 can improve the charge-discharge efficiency of a battery by this configuration. However, in Patent Document 1, the details of the effects of the stability of a counter electrode imparted by an electrode including a halide solid electrolyte, an active material, and a current collector are not clarified.

[0162] The present inventors have studied batteries including a halide solid electrolyte material, an active material, and a current collector. As a result, the present inventors have found that, when charge-discharge, that is, redox reactions are repeatedly performed in a state in which a halide solid electrolyte material is in contact with copper, copper is eluted into the halide solid electrolyte material, diffuses, and is deposited. Then, the present inventors have found that this causes a decrease in the ionic conductivity of the halide solid electrolyte material and an impediment to the reaction interface between the active material and the halide solid electrolyte material, resulting in a problem of a decrease in the cycle characteristics of a battery. It is believed that this problem is caused by the reaction of the halide solid electrolyte material with copper. More specifically, it is believed that the reason is that a bonding site having a high ionic bonding property of M-X of the halide solid electrolyte material reacts. Note that it is believed that such a phenomenon is difficult to occur at a bonding site having a high covalent bonding property of P-S of a sulfide solid electrolyte material and M-O of an oxide solid electrolyte material. That is, it is believed that the above problem is a problem specific to halide solid electrolyte materials.

[0163] The inventors of the present application further conducted research based on the above knowledge. As a result, it was found that, regarding the electrode current collector layer, by setting the copper content in the surface material in contact with the electrode-forming layer containing the halide solid electrolyte material to be lower than 50 mass%, even in a configuration in which the halide solid electrolyte material is combined with the current collector, it is possible to suppress the decrease in the ionic conductivity of the halide solid electrolyte material. As described above, in the electrode 1000 in Embodiment 1, the copper content in the surface material in contact with the electrode-forming layer 110 containing the halide solid electrolyte material 111 in the electrode current collector layer 100 is lower than 50 mass%. Thus, the electrode 1000 in Embodiment 1 can improve the cycle characteristics of the battery by suppressing the decrease in the ionic conductivity of the halide solid electrolyte material 111 caused by the charge and discharge of the battery. The copper content in the surface material can be 25 mass% or less, or 10 mass% or less. Thus, the electrode 1000 in Embodiment 1 can further improve the cycle characteristics of the battery.

[0164] In the electrode 1000 in Embodiment 1, the copper content in the surface material in contact with the electrode-forming layer 110 in the electrode current collector layer 100 can also be 4.5 mass% or less. In the case where the copper content in the surface material is 4.5 mass% or less, the electrode 1000 in Embodiment 1 can further improve the cycle characteristics of the battery because the decrease in the ionic conductivity of the halide solid electrolyte material 111 caused by the charge and discharge of the battery and the hindrance of the reaction interface between the active material and the halide solid electrolyte material are suppressed.

[0165] Hereinafter, the "surface material in the electrode current collector layer 100 in contact with the electrode-forming layer 110" is sometimes omitted as "surface material".

[0166] In the electrode 1000 in Embodiment 1, the copper content in the surface material in contact with the electrode-forming layer 110 in the electrode current collector layer 100 can also be 4.5 mass% or less. In the case where the copper content in the surface material is 4.5 mass% or less, the electrode 1000 in Embodiment 1 can further improve the cycle characteristics of the battery because the decrease in the ionic conductivity of the halide solid electrolyte material 111 caused by the charge and discharge of the battery and the hindrance of the reaction interface between the active material and the halide solid electrolyte material are suppressed.

[0167] In the case where the surface material contains copper, the copper content in the surface material can also be 0.03 mass% or more.

[0168] In the electrode 1000 in Embodiment 1, if the copper content of the surface material of at least the surface of the electrode current collector layer 100 that is in contact with the electrode mixture layer 110 is less than 50% by mass, the surface material can also contain copper. If the copper content is less than 50% by mass, the electrode 1000 in Embodiment 1 can achieve both an increase in the strength of the electrode current collector layer 100 and suppression of a decrease in the ionic conductivity of the halide solid electrolyte material 111, further improving the cycle characteristics of the battery.

[0169] In the electrode 1000 in Embodiment 1, the copper content of the surface material of at least the surface of the electrode current collector layer 100 that is in contact with the electrode mixture layer 110 can also be 4.5% by mass or less. If the copper content is 4.5% by mass or less, the electrode 1000 in Embodiment 1 can more effectively suppress the reaction of the halide solid electrolyte material 111 with copper, further improving the cycle characteristics of the battery.

[0170] Examples of the material used in the surface material in Embodiment 1 are carbon (C), silicon (Si), bismuth (Bi), antimony (Sb), lead (Pb), tin (Sn), iron (Fe), chromium (Cr), zinc (Zn), tantalum (Ta), nickel (Ni), cobalt (Co), cadmium (Cd), manganese (Mn), zirconium (Zr), titanium (Ti), aluminum (Al), beryllium (Be), thorium (Th), magnesium (Mg), sodium (Na), calcium (Ca), strontium (Sr), barium (Ba), potassium (K), rubidium (Rb), cesium (Cs), lithium (Li), vanadium (V), tungsten (W), copper (Cu), silver (Ag), gold (Au), or platinum (Pt). The surface material in Embodiment 1 preferably contains at least one selected from carbon (C), iron (Fe), nickel (Ni), and aluminum (Al). The surface material can also contain an alloy of the above metals. The surface material can also include aluminum as a main component. Among them, “the surface material includes aluminum as a main component” means that the aluminum content of the surface material is 50% by mass or more. The surface material can further include an element other than aluminum. The surface material can include an aluminum alloy. Note that in the case where the surface material includes only aluminum, i.e., the aluminum content of the surface material is 100% by mass, there can be a possibility that the strength is insufficient. Therefore, the surface material preferably contains an element other than aluminum. Furthermore, the aluminum content of the surface material can be 99% by mass or less, or 90% by mass or less.

[0171] The surface material can also contain at least one of carbon (C), silicon (Si), bismuth (Bi), antimony (Sb), lead (Pb), tin (Sn), iron (Fe), chromium (Cr), zinc (Zn), tantalum (Ta), nickel (Ni), cobalt (Co), cadmium (Cd), manganese (Mn), zirconium (Zr), titanium (Ti), beryllium (Be), thorium (Th), magnesium (Mg), sodium (Na), calcium (Ca), strontium (Sr), barium (Ba), potassium (K), rubidium (Rb), cesium (Cs), lithium (Li), vanadium (V), tungsten (W), copper (Cu), silver (Ag), gold (Au), and platinum (Pt).

[0172] When the surface material contains iron, the content of iron is 50% by mass or less, and can be 1.5% by mass or less. When the charging and discharging, that is, the redox reaction, is repeatedly performed in a state where the halide solid electrolyte material is in contact with iron, corrosion of iron can occur in the halide solid electrolyte material. Then, it can cause a decrease in ionic conductivity of the halide solid electrolyte material and an increase in resistance of the halide solid electrolyte material, thereby reducing the stability of the electrode. However, when the content of iron is 50% by mass or less, and particularly 1.5% by mass or less, even in a configuration in which the halide solid electrolyte material is combined with the current collector, a decrease in ionic conductivity of the halide solid electrolyte material can be suppressed, and as a result, the stability of the electrode 1000 can be improved.

[0173] The surface material can also contain other elements or components other than the above-described materials in a range in which the above-described problems can be solved, taking into account contamination and the like. For example, an unavoidable oxide film or the like can be formed in a part of the surface of the electrode current collector layer 100. That is, the surface material can also contain an unavoidable oxide or the like.

[0174] In the electrode 1000, the electrode current collector layer 100 can be configured as long as at least the surface in contact with the electrode agent layer 110 is composed of the surface material. The electrode current collector layer 100 can be configured such that only the surface is composed of the surface material, or the entire surface and the inside can be composed of the same material as the surface material.

[0175] For example, the electrode current collector layer 100 in which the surface in contact with the electrode agent layer 110 is composed of the surface material can be produced by covering the surface of the material configuring the inside of the electrode current collector layer 100 with the surface material by plating or sputtering or the like. Further, the electrode current collector layer 100 in which the surface in contact with the electrode agent layer 110 is composed of the surface material can be produced by applying a solution of the surface material or a dispersion liquid of the surface material to the surface of the material configuring the inside of the electrode current collector layer 100 by a gravure coater or a die coater or the like.

[0176] The thickness of the electrode current collector layer 100 can also be 0.1 μm to 1 mm. In the case where the thickness of the electrode current collector layer 100 is 0.1 μm or more, the strength of the electrode current collector layer 100 is increased, and thus breakage of the electrode current collector layer 100 can be suppressed. In addition, in the case where the thickness of the electrode current collector layer 100 is 1 mm or less, the resistance of the electrode 1000 is reduced, and thus it becomes easy for the battery to operate at a high output. That is, if the thickness of the electrode current collector layer 100 is appropriately adjusted, stable production of the battery can be ensured, and the battery can be caused to operate at a high output.

[0177] As the material of the electrode current collector layer 100 in Embodiment 1, a metal or a metal alloy can also be used. Examples of the metal are aluminum, iron, or copper, and the like. Examples of the metal alloy are aluminum alloy or stainless steel (SUS), and the like.

[0178] The electrode current collector layer 100 can also contain aluminum as a main component. Here, "the electrode current collector layer 100 contains aluminum as a main component" means that the content rate of aluminum in the electrode current collector layer 100 is 50 mass% or more. Aluminum is a lightweight metal having high electrical conductivity. Therefore, the electrode 1000 provided with the electrode current collector layer 100 containing aluminum as a main component, when used in a battery, can not only improve the cycle characteristics of the battery, but also further improve the weight energy density of the battery. The electrode current collector layer 100 containing aluminum as a main component can further include an element other than aluminum. Note that in the case where the electrode current collector layer 100 includes only aluminum, that is, in the case where the content rate of aluminum in the electrode current collector layer 100 is 100%, the strength can be insufficient. Therefore, the electrode current collector layer 100 preferably contains an element other than aluminum. In addition, the content rate of aluminum in the electrode current collector layer 100 can also be 99 mass% or less, or 90 mass% or less.

[0179] The electrode current collector layer 100 can also contain an aluminum alloy. Aluminum alloy is lightweight and has high strength. Therefore, the electrode 1000 provided with the electrode current collector layer 100 containing an aluminum alloy can realize a battery that has both a high weight energy density and high durability. The aluminum alloy is not particularly limited. For example, Al-Cu alloy, Al-Mn alloy, Al-Mn-Cu alloy, or Al-Fe-Cu alloy, and the like can be exemplified.

[0180] As the material of the electrode current collector layer 100 in Embodiment 1, an Al-Mn-Cu alloy can also be used. The Al-Mn-Cu alloy has high strength, and has excellent formability and corrosion resistance. Therefore, the electrode 1000 provided with the electrode current collector layer 100 containing an Al-Mn-Cu alloy can further improve the cycle characteristics of the battery.

[0181] For the electrode current collector layer 100 in Embodiment 1, an electrode current collector layer in which a carbon (C) material is provided as a surface material on the surface of the above-described aluminum alloy can also be used. Examples of the carbon material are graphite such as natural graphite and artificial graphite, carbon black such as acetylene black and ketjen black, or electrically conductive fibers such as carbon fibers. By providing a carbon material as a surface material on the aluminum alloy, improvement in the corrosion resistance of the electrode current collector layer 100 can be sought.

[0182] As a method of manufacturing the electrode 1000 in Embodiment 1, for example, a method in which a dispersion containing the halide solid electrolyte material 111 and the active material 112 that constitute the electrode mixture layer 110 is applied to the electrode current collector layer 100 can be cited. As the dispersion, a slurry obtained by dispersing the halide solid electrolyte material 111 and the active material 112 in a solvent can also be used. As the solvent, a solvent that does not react with the halide solid electrolyte, such as an aromatic solvent like toluene, can be used. Examples of the application method are die coating, gravure coating, blade coating, bar coating, spray coating, or electrostatic coating.

[0183] (Embodiment 2)

[0184] Hereinafter, Embodiment 2 will be described. Descriptions repeated from Embodiment 1 described above will be appropriately omitted.

[0185] Figure 2 A cross-sectional view of the battery 2000 of Embodiment 2 is shown.

[0186] The battery 2000 in Embodiment 2 has a positive electrode 201, a negative electrode 203, and an electrolyte layer 202.

[0187] At least one selected from the positive electrode 201 and the negative electrode 203 is the electrode (for example, the electrode 1000) in Embodiment 1 described above. That is, at least one selected from the positive electrode 201 and the negative electrode 203 has the electrode mixture layer 110 and the electrode current collector layer 100 described in Embodiment 1.

[0188] The electrolyte layer 202 is disposed between the positive electrode 201 and the negative electrode 203.

[0189] With the above configuration, the battery 2000 of Embodiment 2 can improve the cycle characteristics.

[0190] In addition, in the battery 2000 in Embodiment 2, the positive electrode 201 can also be the electrode 1000 in Embodiment 1 described above. In this case, the positive electrode 201 has the electrode mixture layer 110 and the electrode current collector layer 100 described in Embodiment 1.

[0191] According to the above configuration, the cycle characteristics of the battery 2000 can be further improved.

[0192] The electrolyte layer 202 is a layer containing an electrolyte material. The electrolyte material is, for example, a solid electrolyte material. That is, the electrolyte layer 202 can also be a solid electrolyte layer. As the solid electrolyte material contained in the electrolyte layer 202, for example, a sulfide solid electrolyte material, an oxide solid electrolyte material, a halide solid electrolyte material, a polymer solid electrolyte material, and a complex hydride solid electrolyte material, etc. can be used. The solid electrolyte material can also be, for example, a halide solid electrolyte material.

[0193] The "oxide solid electrolyte material" in the present disclosure refers to a solid electrolyte material containing oxygen. Among them, the oxide solid electrolyte material can further contain anions other than oxygen and halogen elements as anions other than oxygen.

[0194] The "halide solid electrolyte material" corresponds to the solid electrolyte material 111 contained in the electrode mixture layer 110 in Embodiment 1 as described in Embodiment 1.

[0195] As the sulfide solid electrolyte material, for example, Li2S-P2S5, Li2S-SiS2, Li2S-B2S3, Li2S-GeS2, Li 3.25 Ge 0.25 P 0.75 S4, and Li 10 GeP2S 12 , etc. can be used. In addition, LiX, Li2O, MO q , and / or Li p MO q , etc. can be added thereto. Among them, the element X in "LiX" is at least one selected from F, Cl, Br, and I. In addition, the element M in "MO q " and "Li p MO q " is at least one selected from P, Si, Ge, B, Al, Ga, In, Fe, and Zn. In addition, p and q in "MO q " and "Li p MO q " are both natural numbers.

[0196] As the oxide solid electrolyte material, for example, a NASICON-type solid electrolyte material represented by LiTi2(PO4)3 and an element-substituted body thereof, a perovskite-type solid electrolyte material of (LaLi)TiO3, a LISICON-type solid electrolyte material represented by Li 14 ZnGe4O 16 , Li4SiO4, LiGeO4, and an element-substituted body thereof, a garnet-type solid electrolyte material represented by Li7La3Zr2O 12Li3PO4 and N-substituted Li3PO4, glasses and glass-ceramics in which Li2SO4, Li2CO3, etc. are added to Li-B-O compounds such as LiBO2 and Li3BO3, and the like.

[0197] As the polymer solid electrolyte, for example, a compound of a polymer compound and a lithium salt can be used. The polymer compound can also have an ethylene oxide structure. The polymer compound having the ethylene oxide structure can contain a large amount of the lithium salt. Therefore, the ionic conductivity can be further improved. As the lithium salt, LiPF6, LiBF4, LiSbF6, LiAsF6, LiSO3CF3, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2C2F5)2, LiN(SO2CF3)(SO2C4F9), LiC(SO2CF3)3, and the like can be used. The lithium salt can be used alone or two or more kinds can be used in combination.

[0198] As the complex hydride solid electrolyte, for example, LiBH4-LiI, LiBH4-P2S5, and the like can be used.

[0199] Further, the electrolyte layer 202 can also contain a solid electrolyte material as a main component. That is, the electrolyte layer 202 can also contain 70% or more (70% by mass or more) of a solid electrolyte material, for example, in terms of a mass ratio with respect to the entire electrolyte layer 202.

[0200] According to the above configuration, the charge-discharge characteristics of the battery 2000 can be further improved.

[0201] Further, the electrolyte layer 202 can also contain a solid electrolyte material as a main component while further containing unavoidable impurities or starting materials and by-products and decomposition products used at the time of synthesizing the solid electrolyte material, and the like.

[0202] Further, the electrolyte layer 202 can also contain 100% (100% by mass) of a solid electrolyte material, for example, in terms of a mass ratio with respect to the entire electrolyte layer 202 excluding unavoidable impurities.

[0203] According to the above configuration, the charge-discharge characteristics of the battery 2000 can be further improved.

[0204] Further, the electrolyte layer 202 can also contain two or more kinds of the materials listed as the solid electrolyte material. For example, the electrolyte layer 202 can also contain a halide solid electrolyte material and a sulfide solid electrolyte material.

[0205] The thickness of the electrolyte layer 202 can also be 1 μm to 300 μm. In the case where the thickness of the electrolyte layer 202 is 1 μm or more, the possibility of short-circuiting between the positive electrode 201 and the negative electrode 203 becomes lower. Further, in the case where the thickness of the electrolyte layer 202 is 300 μm or less, it becomes easy to operate at a high output power. That is, if the thickness of the electrolyte layer 202 is appropriately adjusted, it is possible to ensure sufficient safety of the battery 2000, and it is possible to cause the battery 2000 to operate at a high output power.

[0206] The shape of the solid electrolyte material contained in the battery 2000 is not limited. The shape of the solid electrolyte material can also be, for example, needle-like, spherical, oval spherical, or the like. The shape of the solid electrolyte material can also be, for example, particulate.

[0207] At least one of the positive electrode 201 and the negative electrode 203 can also contain an electrolyte material, and can also contain, for example, a solid electrolyte material. As the solid electrolyte material, the solid electrolyte material exemplified as the material constituting the electrolyte layer 202 can be used. According to the above configuration, the ion conductivity (for example, lithium ion conductivity) inside the positive electrode 201 or the negative electrode 203 becomes high, and it becomes possible to operate at a high output power.

[0208] Further, the positive electrode 201 or the negative electrode 203 can use a sulfide solid electrolyte material as the solid electrolyte material, and use the halide solid electrolyte material described above as the covering material covering the active material.

[0209] The positive electrode 201 contains, for example, a material having the property of intercalating and deintercalating metal ions (for example, lithium ions) as a positive electrode active material. As the positive electrode active material, the material exemplified in Embodiment 1 described above can also be used.

[0210] In the case where the shape of the solid electrolyte material contained in the positive electrode 201 is particulate (for example, spherical), the median particle diameter of the solid electrolyte material can also be 100 μm or less. In the case where the median particle diameter of the solid electrolyte material is 100 μm or less, the positive electrode active material and the solid electrolyte material can be well dispersed in the positive electrode 201. Thereby, the charge and discharge characteristics of the battery 2000 are improved.

[0211] The median particle diameter of the solid electrolyte material contained in the positive electrode 201 can also be smaller than the median particle diameter of the positive electrode active material. Thereby, the solid electrolyte material and the positive electrode active material can be well dispersed.

[0212] The median particle diameter of the positive electrode active material can also be 0.1 μm to 100 μm. In the case where the median particle diameter of the positive electrode active material is 0.1 μm or more, the positive electrode active material and the solid electrolyte material can be well dispersed in the positive electrode 201. As a result, the charge-discharge characteristics of the battery 2000 are improved. In the case where the median particle diameter of the positive electrode active material is 100 μm or less, the lithium diffusion speed within the positive electrode active material is improved. Therefore, the battery 2000 can operate at a high output power.

[0213] In the case where the volume fraction of the positive electrode active material and the solid electrolyte material contained in the positive electrode 201 is set to "v2: 100-v2", 30 ≤ v2 ≤ 95 can also be satisfied. Here, v2 represents the volume fraction of the positive electrode active material when the total volume of the positive electrode active material and the solid electrolyte material contained in the positive electrode 201 is set to 100. In the case where 30 ≤ v2 is satisfied, it is easy to secure sufficient energy density of the battery 2000. In the case where v2 ≤ 95 is satisfied, it becomes easier for the battery 2000 to operate at a high output power.

[0214] The thickness of the positive electrode 201 can also be 10 μm to 500 μm. In the case where the thickness of the positive electrode 201 is 10 μm or more, it becomes easy to secure sufficient energy density of the battery 2000. In the case where the thickness of the positive electrode 201 is 500 μm or less, it becomes easier for the battery 2000 to operate at a high output power.

[0215] The negative electrode 203 contains, for example, a material having the property of intercalating and deintercalating metal ions (e.g., lithium ions) as a negative electrode active material. As the negative electrode active material, the material exemplified in Embodiment 1 described above can also be used.

[0216] The median particle diameter of the negative electrode active material can also be 0.1 μm to 100 μm. In the case where the median particle diameter of the negative electrode active material is 0.1 μm or more, the negative electrode active material and the solid electrolyte material can be well dispersed in the negative electrode 203. As a result, the charge-discharge characteristics of the battery 2000 are improved. In the case where the median particle diameter of the negative electrode active material is 100 μm or less, the lithium diffusion speed within the negative electrode active material is improved. Therefore, the battery 2000 can operate at a high output power.

[0217] The median particle diameter of the negative electrode active material can also be larger than the median particle diameter of the solid electrolyte material. As a result, the solid electrolyte material and the negative electrode active material can be well dispersed.

[0218] When the volume fraction of the negative electrode active material and the solid electrolyte material contained in the negative electrode 203 is set to "v3: 100-v3", 30≤v3≤95 can also be satisfied. Here, v3 represents the volume fraction of the negative electrode active material when the total volume of the negative electrode active material and the solid electrolyte material contained in the negative electrode 203 is set to 100. When 30≤v3 is satisfied, it is easy to ensure sufficient energy density of the battery 2000. When v3≤95 is satisfied, it becomes easier for the battery 2000 to operate at high output power.

[0219] The thickness of the negative electrode 203 can also be 10 μm to 500 μm. When the thickness of the negative electrode 203 is 10 μm or more, it becomes easy to ensure sufficient energy density of the battery 2000. When the thickness of the negative electrode 203 is 500 μm or less, it becomes easier for the battery 2000 to operate at high output power.

[0220] In order to reduce the interface resistance of each active material and the solid electrolyte material, the positive electrode active material and the negative electrode active material can also be covered with a covering material. As the covering material, a material having low electronic conductivity can be used. As the covering material, an oxide material, an oxide solid electrolyte material, or the like can be used. As the covering material, the materials exemplified in Embodiment 1 described above can also be used.

[0221] In at least one selected from the positive electrode 201, the electrolyte layer 202, and the negative electrode 203, a binder can also be contained for the purpose of improving the adhesion (adhesion property) of the particles to each other. As the binder, for example, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, an aromatic polyamide resin, a polyamide, a polyimide, a polyamide-imide, a polyacrylonitrile, a polyacrylic acid, a polymethyl acrylate, a polyethyl acrylate, a polyhexyl acrylate, a polymethyl methacrylate, a polyethyl methacrylate, a polyhexyl methacrylate, a polyvinyl acetate, a polyvinyl pyrrolidone, a polyether, a polycarbonate, a polyether sulfone, a polyether ketone, a polyether ether ketone, a polyphenylene sulfide, hexafluoropolypropylene, a butadiene-styrene rubber, carboxymethyl cellulose, ethyl cellulose, and the like can be exemplified. Furthermore, a copolymer containing two or more kinds selected from tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether, vinylidene fluoride, chlorotrifluoroethylene, ethylene, propylene, butadiene, styrene, pentafluoropropylene, fluoromethyl vinyl ether, acrylate, acrylic acid, and hexadiene as monomers can also be used. They can be used alone as one kind, or two or more kinds can be used in combination.

[0222] As the binder, an elastomer can also be used from the viewpoint of excellent adhesiveness. Note that the elastomer refers to a polymer having elasticity. Further, the elastomer used as the binder can be a thermoplastic elastomer or a thermosetting elastomer. The binder can include a thermoplastic elastomer. As the thermoplastic elastomer, for example, styrene-ethylene-butylene-styrene (SEBS), styrene-ethylene-propylene-styrene (SEPS), styrene-ethylene-ethylene-propylene-styrene (SEEPS), butylene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), styrene-butylene rubber (SBR), styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), hydrogenated isoprene rubber (HIR), hydrogenated butyl rubber (HIIR), hydrogenated nitrile-butyl rubber (HNBR), hydrogenated styrene-butylene rubber (HSBR), polyvinylidene fluoride (PVdF), and polytetrafluoroethylene (PTFE), or the like can be given. Further, two or more kinds selected from them can be mixed and used. In the case where the binder includes a thermoplastic elastomer, when heat compression is performed at the time of manufacturing the battery, high filling of the electrode 1000 can be achieved.

[0223] In at least one of the positive electrode 201, the electrolyte layer 202, and the negative electrode 203, a non-aqueous electrolytic solution, a gel electrolyte, or an ionic liquid can be contained for the purpose of making the transfer of lithium ions easy and improving the output power characteristics of the battery 2000.

[0224] The non-aqueous electrolytic solution includes a non-aqueous solvent and a lithium salt dissolved in the non-aqueous solvent. As the non-aqueous solvent, 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 solvent, or the like can be used. As the cyclic carbonate solvent, ethylene carbonate, propylene carbonate, butylene carbonate, or the like can be given. As the chain carbonate solvent, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, or the like can be given. As the cyclic ether solvent, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, or the like can be given. As the chain ether solvent, 1,2-dimethoxyethane, 1,2-diethoxyethane, or the like can be given. As the cyclic ester solvent, γ-butyrolactone, or the like can be given. As the chain ester solvent, methyl acetate, or the like can be given. As the fluorine solvent, fluoroethylene carbonate, fluoromethyl propionate, fluorobenzene, fluoromethyl ethyl carbonate, fluorodiethyl carbonate, or the like can be given. As the non-aqueous solvent, one kind of non-aqueous solvent selected from them can be used alone, or a mixture of two or more kinds of non-aqueous solvents selected from them can be used.

[0225] In the non-aqueous electrolytic solution, at least one fluorine solvent selected from fluoroethylene carbonate, fluoromethyl propionate, fluorobenzene, fluoromethyl ethyl carbonate, and fluorodiethyl carbonate can be contained.

[0226] As the lithium salt, LiPF6, LiBF4, LiSbF6, LiAsF6, LiSO3CF3, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2C2F5)2, LiN(SO2CF3)(SO2C4F9), and LiC(SO2CF3)3, etc. can be exemplified. As the lithium salt, one lithium salt selected from among them can be used alone, or a mixture of two or more lithium salts selected from among them can be used. The concentration of the lithium salt can be, for example, 0.5 to 2 moles / liter.

[0227] As the gel electrolyte, a material containing a nonaqueous electrolyte solution in a polymer material can be used. As the polymer material, polyethylene oxide, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, and a polymer having an oxirane bond, etc. can be exemplified.

[0228] The cation constituting the ionic liquid can also be an aliphatic chain quaternary cation such as tetraalkylammonium and tetraalkylphosphonium, an aliphatic cyclic ammonium such as pyrrolidinium, morpholinium, imidazolinium, tetrahydropyrimidinium, piperazinium, and piperidinium, a nitrogen-containing heterocyclic aromatic cation such as pyridinium and imidazolium, etc. The anion constituting the ionic liquid can also be PF6 - , BF4 - , SbF6 - , AsF6 - , SO3CF3 - , N(SO2F)2 - , N(SO2CF3)2 - , N(SO2C2F5)2 - , N(SO2CF3)(SO2C4F9) - , and C(SO2CF3)3 - , etc. The ionic liquid can also contain a lithium salt.

[0229] For the purpose of improving electronic conductivity, at least one of the positive electrode 201 and the negative electrode 203 can also contain a conductive aid. As the conductive aid, for example, graphite such as natural graphite and artificial graphite, carbon black such as acetylene black and ketjen black, conductive fibrous materials such as carbon fibers and metal fibers, conductive powdery materials such as fluorinated carbon and aluminum, conductive whiskers such as zinc oxide and potassium titanate, conductive metal oxides such as titanium oxide, conductive polymers such as polyaniline, polypyrrole, and polythiophene, etc. can be used. If a carbon material is used as the conductive aid, cost reduction can be sought.

[0230] The shape of the battery can be, for example, coin type, cylindrical type, square type, sheet type, button type, flat type, and stacked type, etc.

[0231] The battery 2000 in Embodiment 2 can also be manufactured, for example, by preparing a current collector material for the positive electrode, a material for forming the positive electrode, a material for forming the electrolyte layer, a material for forming the negative electrode, and a current collector material for the negative electrode, respectively, and producing a laminate in which the positive electrode, the electrolyte layer, and the negative electrode are sequentially disposed by a publicly known method.

[0232] Example

[0233] Hereinafter, the details of the present disclosure will be described using examples and comparative examples. Note that the electrode and the battery of the present disclosure are not limited to the examples below.

[0234] <Example 1>

[0235] [Production of halide solid electrolyte material]

[0236] In an argon glove box in which the dew point was -60°C or lower, YCl3, LiCl, and LiBr were weighed as raw material powders in a molar ratio of YCl3:LiCl:LiBr = 1:1:2. After that, these raw material powders were mixed, and the obtained mixture was subjected to a calcination treatment at 520°C for 2 hours using an electric furnace to obtain Li3YBr2Cl4 (hereinafter referred to as "LYBC") as a halide solid electrolyte material. After adding p-chloromethylbenzene to the obtained LYBC, pulverization was performed using a wet-type pulverizer, and then drying was performed to obtain LYBC fine powder (median particle diameter D50 = 0.4 μm). 50

[0237] [Production of sulfide solid electrolyte material]

[0238] In an argon glove box in which the dew point was -60°C or lower, Li2S and P2S5 were weighed as raw material powders in a molar ratio of Li2S:P2S5 = 75:25. These raw material powders were pulverized and mixed using a mortar. After that, the obtained mixture was subjected to a grinding treatment using a planetary ball mill (P-7 manufactured by FRITSCH Co., Ltd.) at 510 rpm for 10 hours. The obtained glassy solid electrolyte was subjected to a heat treatment at 270°C for 2 hours in an inert atmosphere. By the above operation, Li2S-P2S5 (hereinafter referred to as "LPS") was obtained as a glass-ceramic solid electrolyte material.

[0239] [Production of positive electrode]

[0240] ​In an argon glove box in which the dew point was -60°C or less, LYBC fine powder and positive electrode active material (Li(Ni, Co, Mn)02) were weighed in such a way that the mass ratio became LYBC:Li(NiCoMn)02= 18.45:81.55. An electrode mixture was prepared by mixing them in a agate mortar. Next, the electrode mixture and SEBS (Asahi Kasei Corporation, Tuftec N504) were weighed in a mass ratio of electrode mixture:SEBS = 100:0.4. The weighed electrode mixture and SEBS were dissolved or dispersed in the solvent p-chlorotoluene, and an electrode mixture slurry was prepared by kneading using a rotation and revolution mixer (THINKY, ARE-310) at 1600 rpm for 6 minutes. As an electrode current collector layer, an aluminum alloy A1085 foil (copper content: 0.03 mass%, thickness: 15 μm) was used. A positive electrode was prepared by applying the electrode mixture slurry on the metal foil and drying at 100°C for 1 hour in a vacuum. In the positive electrode, the halide solid electrolyte material was composed of LYBC, the active material was composed of Li(Ni, Co, Mn)02, and the electrode current collector layer was composed of aluminum alloy A1085.

[0241] [Production of negative electrode mixture]

[0242] In an argon glove box in which the dew point was -60°C or less, LPS and negative electrode active material (graphite) were weighed in such a way that the mass ratio became LPS:graphite = 60:40. A negative electrode mixture was prepared by mixing them in a agate mortar.

[0243] [Production of battery]

[0244] In an insulating outer cylinder, a positive electrode punched to φ9.2 mm, 20 mg of LYBC, 60 mg of LPS, and a negative electrode mixture were sequentially stacked. By pressure molding the obtained stack at a pressure of 740 MPa, a battery composed of a positive electrode, a solid electrolyte layer, and a negative electrode was obtained. In the obtained battery, the thickness of the positive electrode mixture layer was about 60 μm, and the thickness of the positive electrode was about 75 μm.

[0245] Next, stainless steel pins were arranged above and below the battery. A current collecting lead was attached to the stainless steel pins.

[0246] Next, the inside of the insulating outer cylinder was blocked and sealed from the outside air atmosphere using an insulating sleeve.

[0247] Finally, the battery was bound from above and below by 4 bolts, and a surface pressure of 150 MPa was applied to the battery.

[0248] Through the above operations, the battery of Example 1 was fabricated. In the battery of Example 1, the positive electrode is the electrode of this disclosure. In the electrode contained in the battery of Example 1, the copper content of the surface material of the electrode current collector layer in contact with the electrode compound layer is 0.03% by mass.

[0249] <Example 2>

[0250] In the fabrication of the positive electrode, aluminum alloy A2017 foil (copper content: 3.5% to 4.5% by mass, thickness: 10 μm) was used as the electrode current collector layer. All other items were performed in the same manner as in Example 1, resulting in the battery of Example 2. In the electrode contained in the battery of Example 2, the copper content of the surface material of the electrode current collector layer in contact with the positive electrode alloy layer was 3.5% to 4.5% by mass. It should be noted that the "electrode contained in the battery of Example 2" refers to the positive electrode.

[0251] <Example 3>

[0252] In the fabrication of the positive electrode, aluminum alloy A3003 foil (copper content: 0.05% to 0.20% by mass, thickness: 15 μm) was used as the electrode current collector layer. All other items were performed in the same manner as in Example 1, resulting in the battery of Example 3. In the electrode contained in the battery of Example 3, the copper content of the surface material of the electrode current collector layer in contact with the electrode compound layer was 0.05% to 0.20% by mass. It should be noted that the "electrode contained in the battery of Example 3" refers to the positive electrode.

[0253] <Example 4>

[0254] In the fabrication of the positive electrode, aluminum alloy A8021 foil (copper content: 0.05% by mass, thickness: 15 μm) was used as the electrode current collector layer. All other items were performed in the same manner as in Example 1 above, resulting in the battery of Example 4. In the electrode contained in the battery of Example 4, the surface material of the electrode current collector layer in contact with the electrode compound layer has a copper content of 0.05% by mass. It should be noted that the "electrode contained in the battery of Example 4" refers to the positive electrode.

[0255] <Example 5>

[0256] In the fabrication of the positive electrode, a stainless steel SUS304 foil (copper content: 0% by mass, thickness: 10 μm) was used as the electrode current collector layer. All other aspects were performed in the same manner as in Example 1, resulting in the battery of Example 5. In the electrode contained in the battery of Example 5, the surface material of the electrode current collector layer in contact with the electrode compound layer had a copper content of 0% by mass. It should be noted that the "electrode contained in the battery of Example 5" refers to the positive electrode.

[0257] <Comparative Example 1>

[0258] In the production of the positive electrode, as the electrode current collector layer, a rolled copper foil (copper content: more than 99 mass%, thickness: 12 μm) was used. Other than this, the items were implemented in the same manner as the method of Example 1 described above, and the battery of Comparative Example 1 was obtained. The copper content of the surface material of the electrode current collector layer in contact with the electrode mixture layer in the electrode contained in the battery of Comparative Example 1 was >99 mass%.

[0259] <Evaluation of the battery>

[0260] [Charge-discharge test]

[0261] The charge-discharge test was implemented using the batteries of Examples 1 to 5 and Comparative Example 1 described above, respectively, under the following conditions.

[0262] The batteries were arranged in a constant-temperature tank at 25°C.

[0263] The batteries were charged at a current density of a current value of 0.05C rate (20 hour rate) with respect to the theoretical capacity of the positive electrode active material (Li(Ni, Co, Mn)02) until the voltage was 4.2 V. Subsequently, the batteries were discharged at the same current density until the voltage was 2.5 V.

[0264] The above charge-discharge was repeated for 10 cycles.

[0265] Through the above operation, the discharge capacity maintenance rate of the 10th cycle (=discharge capacity of the 10th cycle / initial discharge capacity) was obtained for each of the batteries of Examples 1 to 5 and Comparative Example 1 described above. The results thereof are shown in Table 1.

[0266] [Table 1]

[0267]

[0268] [X-ray photoelectron spectroscopy]

[0269] For the battery of Comparative Example 1 after the implementation of the above charge-discharge test, the electrode current collector layer was peeled off. The elemental analysis of the surface of the positive electrode mixture layer in contact with the electrode current collector layer and the depth direction thereof was implemented by X-ray photoelectron spectroscopy (XPS). The results thereof are shown in Table 2.

[0270] [Table 2]

[0271] Atomic concentration (at. %)

[0272] Depth (nm) Cu Ni Y Br Cl 0 5 2 4 12 19 1 10 5 7 14 25 3 9 6 9 16 29 5 10 10 9 16 27 10 8 11 11 15 25 20 8 15 11 14 23 30 6 16 13 14 21 50 2 22 12 13 19 70 2 22 12 12 15 100 1 28 11 11 13

[0273] <Investigation>

[0274] From the comparison of the results of Examples 1 to 5 with the result of Comparative Example 1 shown in Table 1, it was confirmed that in the case of the battery using the electrode in which the copper content of the surface material of the electrode current collector layer in contact with the electrode mixture layer was less than 50 mass%, the discharge capacity retention rate at the 10th cycle was high, and the cycle characteristics of the battery were improved.

[0275] Further, from the surface and depth analysis of the positive electrode mixture layer of Comparative Example 1 by XPS shown in Table 2, copper (Cu) contained in the electrode current collector layer was detected. From this result, it was inferred that in the case where the charge and discharge, that is, the redox reaction, was repeated, the copper was eluted, diffused, and precipitated into the halide solid electrolyte material.

[0276] From the above, it was confirmed that the cycle characteristics of the battery were improved by using the electrode of the present disclosure. Note that the electrode of the present disclosure refers to the electrode described below:

[0277] which has an electrode mixture layer and an electrode current collector layer,

[0278] wherein the electrode current collector layer is in contact with the electrode mixture layer,

[0279] the electrode mixture layer contains a solid electrolyte material and an active material,

[0280] the solid electrolyte material contains Li, M, and X,

[0281] M is at least one selected from metal elements other than Li and semimetal elements,

[0282] X is at least one selected from F, Cl, Br, and I,

[0283] the copper content of the surface material of the electrode current collector layer in contact with the electrode mixture layer is less than 50 mass%.

[0284] Industrial applicability

[0285] The battery of the present disclosure can be used, for example, as a full solid lithium ion secondary battery or the like.

Claims

1. An electrode comprising: Electrode mixture layer, and Electrode current collector layer, in, The electrode current collector layer is in contact with the electrode mixture layer. The electrode mixture layer contains solid electrolyte materials and active substances. The solid electrolyte material contains Li, M, and X. M is at least one metallic element or half-metallic element selected from elements other than Li. X is selected from at least one of F, Cl, Br and I. The electrode current collector layer comprises an aluminum alloy. In the electrode current collector layer, the copper content in the surface material in contact with the electrode compound layer is less than 50% by mass. The aluminum alloy is an Al-Cu alloy, an Al-Mn-Cu alloy, or an Al-Fe-Cu alloy.

2. The electrode according to claim 1, wherein, The copper content in the surface material is less than 4.5% by mass.

3. The electrode according to claim 2, wherein, The copper content in the surface material is 0.05% by mass or more and 0.20% by mass or less.

4. The electrode according to claim 1, wherein, The solid electrolyte material is represented by the following composition formula (1). Li α M β X γ Formula (1) Wherein, α, β and γ are all values ​​greater than 0.

5. The electrode according to claim 1, wherein, The M contains yttrium.

6. The electrode according to claim 1, wherein, The electrode current collector layer contains aluminum as its main component.

7. The electrode according to claim 6, wherein, The electrode current collector layer further contains elements other than aluminum.

8. The electrode according to claim 1, wherein, The active material is a lithium-containing transition metal oxide.

9. The electrode according to claim 8, wherein, The active material is lithium nickel cobalt manganese oxide.

10. A battery comprising: positive electrode, Negative electrode, and An electrolyte layer disposed between the positive electrode and the negative electrode. in, The electrode selected from at least one of the positive electrode and the negative electrode is any one of claims 1 to 9.

11. The battery according to claim 10, wherein, The positive electrode is the electrode according to any one of claims 1 to 9.

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