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EP-4741347-A1 - ALKALI METAL-CONTAINING OXIDE, ELECTRODE, AND BATTERY

EP4741347A1EP 4741347 A1EP4741347 A1EP 4741347A1EP-4741347-A1

Abstract

The present disclosure provides an alkali metal-containing oxide including an alkali metal element and a metal element M other than the alkali metal element, wherein a ratio X/Y of a substance amount X of the alkali metal element included in the alkali metal-containing oxide to a substance amount Y of the metal element M is 1.2 to 2.0, and the metal element M includes two or more kinds of metal elements M S , each having a valence such that an absolute value of a difference between an average valence for the same element and an integer closest to the average valence is 0.1 to 0.5.

Inventors

  • YAMABAYASHI Tsutomu
  • KAGEYAMA HIROSHI

Assignees

  • Sumitomo Chemical Company, Limited
  • Kyoto University

Dates

Publication Date
20260513
Application Date
20240806

Claims (11)

  1. An alkali metal-containing oxide comprising an alkali metal element and a metal element M other than the alkali metal element, wherein a ratio X/Y of a substance amount X of the alkali metal element included in the alkali metal-containing oxide to a substance amount Y of the metal element M is greater than 1.0 and not more than 2.0, and the metal element M includes two or more kinds of metal elements M S , each having a valence such that an absolute value of a difference between an average valence for a same element and an integer closest to the average valence is 0.1 to 0.5.
  2. The alkali metal-containing oxide according to claim 1, wherein the metal element M S contains V and Mn.
  3. The alkali metal-containing oxide according to claim 1 or 2, wherein the metal element M S includes a combination of two kinds of metal elements in which an absolute value of a difference in average valence is 1 or more.
  4. An alkali metal-containing oxide comprising an alkali metal element and a metal element M other than the alkali metal element, wherein a ratio X/Y of a substance amount X of the alkali metal element included in the alkali metal-containing oxide to a substance amount Y of the metal element M is greater than 1.0 and not more than 2.0, the metal element M includes a metal element M 1 and a metal element M 2 , an average valence for a same element of the metal element M 1 is a non-integer, an average valence for a same element of the metal element M 2 is tetravalent or higher, and a difference: {(the average valence of the metal element M 2 ) - (the average valence of the metal element M 1 )} is 1 or more.
  5. The alkali metal-containing oxide according to claim 4, wherein the metal element M 1 contains Mn, and the metal element M 2 contains V.
  6. The alkali metal-containing oxide according to claim 1 or 4, having a crystal phase of a disordered rock-salt structure.
  7. The alkali metal-containing oxide according to claim 1 or 4, having an amorphous phase.
  8. The alkali metal-containing oxide according to claim 1 or 4, represented by a general formula: A x Mn a M' b V c O 2+y . (In the formula, 1<x≤2.0, 0.3≤a≤0.8, 0≤b≤0.3, 0.3≤c≤0.6, and 0≤y≤1.0, A is an alkali metal element, and M' contains at least one kind of element selected from the group consisting of Cr, Fe, Co, Ni, and Cu.)
  9. The alkali metal-containing oxide according to claim 1 or 4, wherein when powder X-ray diffraction measurement is performed at 25°C using a CuKα ray, a peak having a half width of 0.5 to 5° is observed in a range of 2θ of 42 to 46°.
  10. An electrode comprising the alkali metal-containing oxide according to claim 1 or 4.
  11. A battery comprising the electrode according to claim 10.

Description

Technical Field The present disclosure relates to an alkali metal-containing oxide, an electrode, and a battery. Background Art Secondary batteries that perform charging and discharging by moving alkali metal ions between a positive electrode and a negative electrode are known. Among such secondary batteries, lithium-ion secondary batteries are representative and have already been put into practical use as small power sources for mobile phones, laptop computers, and the like. Furthermore, because lithium-ion secondary batteries can be used as large power sources such as power sources for automobiles such as electric vehicles and hybrid vehicles, and power sources for distributed power storage, the demand for them is increasing. As an attempt to improve the capacity of lithium-ion secondary batteries, Patent Literature 1 discloses a lithium-excess positive electrode material with a high compositional ratio of lithium. Non-Patent Literature 1 reports a lithium-excess positive electrode material having a disordered rock-salt structure, Li1.2Mn0.4Ti0.4O2, and the like. Citation List Patent Literature [Patent Literature 1] Japanese Unexamined Patent Application Publication No. 2008-98154 Non Patent Literature [Non-Patent Literature 1] nature communications 7, Article number: 13814 (2016) Summary of Invention Technical Problem However, existing lithium-excess positive electrode materials are accompanied by voltage hysteresis during charging and discharging, and there is still room for improvement in energy efficiency. The present disclosure has been made in view of the above-described circumstances, and an object thereof is to provide an alkali metal-containing oxide with high energy efficiency, and an electrode and a battery using the same. Solution to Problem The present disclosure includes the following exemplary embodiments. [1] An alkali metal-containing oxide including an alkali metal element and a metal element M other than the alkali metal element, wherein a ratio X/Y of a substance amount X of the alkali metal element included in the alkali metal-containing oxide to a substance amount Y of the metal element M is greater than 1.0 and not more than 2.0, andthe metal element M includes two or more kinds of metal elements MS, each having a valence such that an absolute value of a difference between an average valence for the same element and an integer closest to the average valence is 0.1 to 0.5.[2] The alkali metal-containing oxide of [1], wherein the metal element MS contains V and Mn.[3] The alkali metal-containing oxide of [1] or [2], wherein the metal element MS includes a combination of two kinds of metal elements in which an absolute value of a difference in average valence is 1 or more.[4] An alkali metal-containing oxide including an alkali metal element and a metal element M other than the alkali metal element, wherein a ratio X/Y of a substance amount X of the alkali metal element included in the alkali metal-containing oxide to a substance amount Y of the metal element M is greater than 1.0 and not more than 2.0,the metal element M includes a metal element M1 and a metal element M2,an average valence for the same element of the metal element M1 is a non-integer, an average valence for the same element of the metal element M2 is tetravalent or higher, anda difference: {(the average valence of the metal element M2) - (the average valence of the metal element M1)} is 1 or more.[5] The alkali metal-containing oxide according to [4], wherein the metal element M1 contains Mn, and the metal element M2 contains V.[6] The alkali metal-containing oxide of any one of [1] to [5], having a crystal phase of a disordered rock-salt structure.[7] The alkali metal-containing oxide of any one of [1] to [6], having an amorphous phase.[8] The alkali metal-containing oxide of any one of [1] to [7], wherein when powder X-ray diffraction measurement is performed at 25°C using a CuKα ray, a half width of a peak observed in a range of 2θ of 42 to 46° is 0.5 to 5°.[9] The alkali metal-containing oxide of any one of [1] to [8], represented by a general formula: AxMnaM'bVcO2+y. (In the formula, 1<x≤2.0, 0.3≤a≤0.8, 0≤b≤0.3, 0.3≤c≤0.6, and 0≤y≤1.0, A is an alkali metal element, and M' contains at least one kind of element selected from the group consisting of Cr, Fe, Co, Ni, and Cu.)[10] An electrode including the alkali metal-containing oxide of any one of [1] to [9].[11] A battery including the electrode of [10]. Advantageous Effects of Invention According to the present disclosure, it is possible to provide an alkali metal-containing oxide with high energy efficiency, and an electrode and a battery using the same. Brief Description of Drawings [FIG. 1] FIG. 1 is an X-ray diffraction chart of each lithium-containing oxide of Examples and Comparative Examples.[FIG. 2] FIG. 2 is a diagram showing results of a charge/discharge test of Example 1.[FIG. 3] FIG. 3 is a diagram showing results of a charge/discharge test of Example