KR-102962789-B1 - Positive electrode active material, electrode, and all-solid-state lithium-ion battery for all-solid-state lithium-ion battery

KR102962789B1KR 102962789 B1KR102962789 B1KR 102962789B1KR-102962789-B1

Abstract

A positive electrode active material for an all-solid-state lithium-ion battery comprising particles containing crystals of a lithium metal composite oxide, wherein the lithium metal composite oxide has a layered structure and also contains at least Li and a transition metal, and wherein the particles have a total pore volume of less than 0.0035 cm³/g, which is obtained from the amount of nitrogen adsorbed when the relative pressure (p/ p₀ ) of the adsorption isotherm is 0.99, in terms of pore properties obtained from nitrogen adsorption isotherm measurements and nitrogen desorption isotherm measurements at liquid nitrogen temperature.

Inventors

가도와키 다쿠야
가게우라 준이치
무라카미 지카라

Assignees

스미또모 가가꾸 가부시끼가이샤

Dates

Publication Date: 20260508
Application Date: 20210115
Priority Date: 20200117

Claims (20)

As a positive electrode active material for an all-solid-state lithium-ion battery comprising particles containing crystals of a lithium metal composite oxide, The above lithium metal composite oxide has a layered structure and also contains at least Li and a transition metal, and A positive electrode active material for an all-solid-state lithium-ion battery, wherein, in the pore properties obtained from nitrogen adsorption isotherm measurements and nitrogen desorption isotherm measurements at liquid nitrogen temperature, the total pore volume obtained from the nitrogen adsorption amount when the relative pressure of the adsorption isotherm (p/ p₀ ) is 0.99 is less than 0.0035 cm³/g.
In Article 1, Positive electrode active material for an all-solid-state lithium-ion battery used in an all-solid-state lithium-ion battery containing an oxide-based solid electrolyte.
In Article 1, A positive electrode active material for an all-solid-state lithium-ion battery in contact with a solid electrolyte layer.
In Article 1, A positive electrode active material for an all-solid-state lithium-ion battery, wherein, in the pore distribution obtained from the Taly isotherm by the Barrett-Joyner-Halenda (BJH) method, the ratio of the volume of pores having a diameter of 50 nm or less to the total pore volume of pores having a diameter of 200 nm or less is 45% or more.
In Article 1, A positive electrode active material for an all-solid-state lithium-ion battery, wherein, in a cumulative pore distribution curve obtained by the mercury indentation method, the pore diameter D75 at 25% accumulation is 7.4 μm or less, and the pore diameter D5 at 95% accumulation is 0.0135 μm or more.
In Article 1, A positive electrode active material for an all-solid-state lithium-ion battery in which the above transition metal is at least one element selected from the group consisting of Ni, Co, Mn, Ti, Fe, V, and W.
In Article 6, The above lithium metal composite oxide is a positive electrode active material for an all-solid-state lithium-ion battery represented by the compositional formula (A) shown below. Li[Li x (Ni (1-yzw) Co y Mn z M w ) 1-x ]O 2 Composition formula (A) (However, M is one or more elements selected from the group consisting of Fe, Cu, Ti, Mg, Al, W, B, Mo, Nb, Zn, Sn, Zr, Ga, and V, satisfying -0.10 ≤ x ≤ 0.30, 0 ≤ y ≤ 0.40, 0 ≤ z ≤ 0.40, 0 ≤ w ≤ 0.10, and 0 < y + z + w.)
In Article 7, A positive electrode active material for an all-solid-state lithium-ion battery satisfying 1-yzw ≥ 0.50 and y ≤ 0.30 in the above compositional formula (A).
In Article 1, The above particle is composed of a primary particle, a secondary particle which is an aggregate of the primary particle, and a single particle existing independently of the primary particle and the secondary particle, and A positive electrode active material for an all-solid-state lithium-ion battery in which the content of the single particle in the above particles is 20% or more.
An electrode comprising a positive electrode active material for an all-solid-state lithium-ion battery as described in any one of claims 1 to 9.
In Article 10, Electrode further comprising a solid electrolyte.
having a positive electrode, a negative electrode, and a solid electrolyte layer clamped between the positive electrode and the negative electrode, The above solid electrolyte layer comprises a first solid electrolyte, and The above positive electrode has a positive electrode active material layer in contact with the solid electrolyte layer, and a current collector on which the positive electrode active material layer is stacked. The above positive electrode active material layer comprises a positive electrode active material for an all-solid-state lithium-ion battery as described in any one of claims 1 to 9.
In Article 12, The above positive electrode active material layer is an all-solid-state lithium-ion battery comprising the above positive electrode active material for an all-solid-state lithium-ion battery and a second solid electrolyte.
In Article 13, An all-solid-state lithium-ion battery in which the first solid electrolyte and the second solid electrolyte are the same material.
In Article 12, The above-mentioned first solid electrolyte is an all-solid-state lithium-ion battery having an amorphous structure.
In Article 12, The first solid electrolyte above is an all-solid-state lithium-ion battery that is an oxide-based solid electrolyte.
A positive electrode in contact with a solid electrolyte layer, wherein the positive electrode comprises a positive electrode active material layer in contact with the solid electrolyte layer and a current collector on which the positive electrode active material layer is stacked, and the positive electrode active material layer comprises a positive electrode active material composed of particles including crystals of a lithium metal composite oxide. The above lithium metal composite oxide has a layered structure and also contains at least Li and a transition metal, and The above positive electrode active material is a positive electrode having a total pore volume of less than 0.0035 cm³/g, which is obtained from the nitrogen adsorption amount when the relative pressure (p/ p₀ ) of the adsorption isotherm is 0.99, in the pore properties obtained from the nitrogen adsorption isotherm measurement and the nitrogen desorption isotherm measurement at liquid nitrogen temperature.
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Description

Positive electrode active material, electrode, and all-solid-state lithium-ion battery for all-solid-state lithium-ion battery The present invention relates to a positive electrode active material, an electrode, and an all-solid-state lithium-ion battery for an all-solid-state lithium-ion battery. The present application claims priority based on Japanese Patent Application No. 2020-006341 filed in Japan on January 17, 2020, and incorporates the contents thereof herein by reference. Research on lithium-ion rechargeable batteries is actively underway for applications such as power sources for electric vehicles and household storage batteries. Among these, all-solid-state lithium-ion rechargeable batteries offer advantages over conventional lithium-ion rechargeable batteries using liquid electrolytes, such as higher energy density, a wider operating temperature range, and resistance to degradation. For this reason, all-solid-state lithium-ion rechargeable batteries are attracting attention as next-generation energy storage devices. In the following description, "conventional lithium-ion secondary battery using an electrolyte" may be referred to as a "liquid-based lithium-ion secondary battery" to distinguish it from an all-solid-state lithium-ion secondary battery. Patent Document 1 describes an all-solid-state lithium-ion secondary battery using LiNi 1/3 Mn 1/3 Co 1/3 O 2 as a positive electrode active material. LiNi 1/3 Mn 1/3 Co 1/3 O 2 is a well-known material used as a positive electrode active material for liquid-based lithium-ion secondary batteries. FIG. 1 is a schematic diagram showing a laminated structure provided by an all-solid-state lithium-ion battery of an embodiment. FIG. 2 is a schematic diagram showing the overall configuration of an all-solid-state lithium-ion battery of an embodiment. <Positive electrode active material for all-solid-state lithium-ion batteries> In the case where a coating layer composed of the metal composite oxide described below is provided on the surface of a particulate lithium metal composite oxide, the particle having the coating layer corresponds to a "particle comprising a crystal of lithium metal composite oxide" related to one aspect of the present invention. In addition, if the surface of the particulate lithium metal composite oxide does not have a coating layer made of a metal composite oxide, the lithium metal composite oxide corresponds to the "particle comprising a crystal of lithium metal composite oxide" related to one aspect of the present invention. The positive electrode active material for an all-solid-state lithium-ion battery according to the present embodiment is a particle comprising crystals of a lithium metal composite oxide. The positive electrode active material for an all-solid-state lithium-ion battery according to the present embodiment is a positive electrode active material preferably used in an all-solid-state lithium-ion battery comprising an oxide-based solid electrolyte. Hereinafter, the positive electrode active material for an all-solid-state lithium-ion battery according to the present embodiment may be simply referred to as the "positive electrode active material." The positive electrode active material satisfies the following requirements. (Requirement 1) The lithium metal composite oxide included in the positive electrode active material has a layered structure and also includes at least Li and a transition metal. In addition, in this specification, the term "transition metal" refers to a transition metal element. (Requirement 2) In the pore properties of the positive electrode active material obtained from the nitrogen adsorption isotherm measurement and the nitrogen desorption isotherm measurement at liquid nitrogen temperature, the total pore volume obtained from the nitrogen adsorption amount when the relative pressure of the adsorption isotherm (p/ p₀ ) is 0.99 is less than 0.0035 cm³/g. The following is explained in order. (Requirement 1: Lithium metal composite oxide) The lithium metal composite oxide comprises at least one element selected from the group consisting of Ni, Co, Mn, Ti, Fe, V, and W as a transition metal. When the lithium metal composite oxide includes at least one type selected from the group consisting of Ni, Co, and Mn as a transition metal, the resulting lithium metal composite oxide forms a stable crystal structure capable of extracting or inserting lithium ions. Therefore, when the positive electrode active material is used as the positive electrode of an all-solid-state lithium-ion battery, high charge capacity and discharge capacity are obtained. In addition, when the lithium metal composite oxide includes at least one selected from the group consisting of Ti, Fe, V, and W, the obtained lithium metal composite oxide has a robust crystal structure. Therefore, the positive electrode active material has high thermal stability. In addition, such a positive electrode active material can improve the cycl