Solid electrolyte-containing dispersion, all-solid-state lithium-ion secondary battery, and method for manufacturing an all-solid-state lithium-ion secondary battery

Abstract

The present invention provides a solid electrolyte-containing dispersion suitable for forming an oxide-based solid electrolyte layer containing a combination of lithium tetraborate and a lithium salt, which contains finer solid particles while exhibiting excellent stability over time, as well as an all-solid-state lithium-ion secondary battery including a solid electrolyte layer formed using the solid electrolyte-containing dispersion, and a method for manufacturing the same. [Solution] In an all-solid-state lithium-ion secondary battery 10 having a positive electrode layer composed of a positive electrode active material layer 4, a solid electrolyte layer 3 formed using a solid electrolyte-containing dispersion, and a negative electrode layer composed of a negative electrode active material layer 2, the solid electrolyte-containing dispersion contains lithium tetraborate, a lithium salt, a carboxymethylcellulose compound, and water, the water content in the solid electrolyte-containing dispersion is 15 to 68% by mass, and the particle size measured by a particle gauge determined using the solid electrolyte-containing dispersion is 50 μm or less.

Claims

1. A dispersion containing a solid electrolyte, The above solid electrolyte-containing dispersion contains lithium tetraborate, a lithium salt, a carboxymethylcellulose compound, and water. The water content in the solid electrolyte-containing dispersion is 15 to 68% by mass. The particle size measured by the particle gauge, determined using the aforementioned solid electrolyte-containing dispersion, is 50 μm or less. Solid electrolyte-containing dispersion.

2. The solid electrolyte-containing dispersion according to claim 1, wherein the water content is 20 to 50% by mass.

3. The solid electrolyte-containing dispersion according to claim 1, wherein the content of the lithium salt (lithium salt / lithium tetraborate) relative to the content of the lithium tetraborate is 0.0010 to 3.0000 in molar ratio.

4. where the lithium salt is LiN(R ｆ１ SO ２ )(R ｆ２ SO ２ ), LiF, LiCl, LiBr, LiI, CH ３ COOLi, Li ２ CO ３ ), LiCF ３ SO ３ ), LiC ４ F ９ SO ３ ), Li ２ SO ４ ), LiClO ４ ), LiH ２ PO ４ ), LiNO ３ ), and at least one of Li ３ C ６ H ５ O ７ ; the solid electrolyte-containing dispersion according to claim 1. However, R ｆ１ and R ｆ２ Each of these independently represents a halogen atom or a perfluoroalkyl group.

5. The lithium salt is LiN(R) ｆ１ SO ２ ) (Caution ｆ２ SO ２ ), CH ３ COOLi, Li ２ CO ３ LiCF ３ SO ３ LiC ４ F ９ SO ３ Li ２ SO ４ LiClO ４ LiH ２ PO ４ LiNO ３ , and Li ３ C ６ H ５ O ７ A solid electrolyte-containing dispersion according to claim 1, comprising at least one of the following. However, R ｆ１ and R ｆ２ Each of these independently represents a halogen atom or a perfluoroalkyl group.

6. The solid electrolyte-containing dispersion according to claim 1, wherein the content of the carboxymethylcellulose compound is 1.0 to 12.0 parts by mass per 100.0 parts by mass of lithium tetraborate.

7. The solid electrolyte-containing dispersion according to claim 1, wherein the weight-average molecular weight of the carboxymethylcellulose compound is 40,000 to 10,000,000.

8. The solid electrolyte-containing dispersion according to claim 7, wherein the carboxymethylcellulose compound has a weight-average molecular weight of 1,000,000 to 1,000,000 and a degree of etherification of 0.50 to 1.

50.

9. The solid electrolyte-containing dispersion according to claim 1, wherein the pH of the solid electrolyte-containing dispersion is 5.1 to 8.

6.

10. Shear rate 1s －１ The solid electrolyte-containing dispersion according to claim 1, wherein the shear viscosity in is 100 to 1,000,000 mPa·s.

11. An all-solid-state lithium-ion secondary battery having a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, An all-solid-state lithium-ion secondary battery, wherein the solid electrolyte layer is formed using a solid electrolyte-containing dispersion according to any one of claims 1 to 10.

12. A method for producing an all-solid-state lithium-ion secondary battery, comprising forming a solid electrolyte layer using a solid electrolyte-containing dispersion according to any one of claims 1 to 10.

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