Solid electrolyte and preparation method thereof, and electrochemical device and electronic device comprising same

Patent metadata

Field	Value
Publication number	US-11050081-B2
Application number	US-201916458510-A
Country	US
Kind code	B2
Filing date	Jul 1, 2019
Priority date	Mar 13, 2019
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

Embodiments of the present application relate to a solid electrolyte and a preparation method thereof, and an electrochemical device and an electronic device comprising the same. The solid electrolyte of the present application includes a solid electrolyte material being represented by the chemical formula of Li1+2x−2yMyGa2+xP1−xS6, where M is selected from the group consisting of Sr, Ba, Zn, Cd and a combination thereof, 0≤x≤0.2 and 0≤y≤0.05. Embodiments of the present application provides a solid electrolyte having good stability with lithium and ionic conductivity by forming the solid electrolyte using lower cost solid electrolyte materials and optimizing the material composition and a crystal structure thereof. At the same time, this also reduces the manufacturing costs of the solid electrolyte, and improves the structural stability of the solid electrolyte.

First claim

What is claimed is:

1. An electrolyte comprising a solid electrolyte, wherein the solid electrolyte comprises a solid electrolyte material being represented by a chemical formula of Li 1+2x−2y M y Ga 2+x P 1−x S 6 , wherein M is selected from a group consisting of Sr, Ba, Zn, Cd and a combination thereof, 0≤x≤0.2 and 0≤y≤0.05.

2. The electrolyte according to claim 1 , wherein the solid electrolyte material belongs to a monoclinic crystal system and has a crystal structure of a diamond-like structure.

3. The electrolyte according to claim 2 , wherein the crystal structure is composed of corner-sharing tetrahedral structural units.

4. The electrolyte according to claim 2 , wherein a space group of the crystal structure of the solid electrolyte material is Cc, and primitive vectors of a unit cell of the crystal structure are a=11.373±0.5 Å, b=6.946±0.5 Å and c=11.401±0.5 Å.

5. The electrolyte according to claim 1 , further comprising a binder, wherein a mass percentage of the binder is about 10% to about 20% based on a total mass of the solid electrolyte, and the binder is selected from a group consisting of polypropylene, polyethylene, poly(ethylene oxide), polyphenylene oxide, polyvinylidene fluoride, a vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate ester, polyacrylic acid, polyacrylate salt, carboxymethyl cellulose sodium, polyvinylpyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, polyhexafluoropropylene, styrene-butadiene rubber and a combination thereof.

6. The electrolyte according to claim 1 , wherein the solid electrolyte material has ionic conductivity of about 10 −6 S/cm to about 10 −4 S/cm and a lithium ion migration barrier of less than about 0.4 eV.

7. A method for preparing the electrolyte according to claim 1 , the method comprising the following steps:
mixing a lithium (Li)-containing material, an M-containing material, a gallium (Ga)-containing material, a phosphorus (P)-containing material and a sulfur (S)-containing material according to a stoichiometric ratio of Li 1+2x−2y M y Ga 2+x P 1−x S 6 to form a mixture, wherein M is selected from the group consisting of Sr, Ba, Zn, Cd and a combination thereof, 0≤x≤0.2 and 0≤y≤0.05;
heating the mixture to a solid phase reaction critical temperature, and then cooling to obtain the solid electrolyte material; and
forming the solid electrolyte by using the solid electrolyte material.

8. The method according to claim 7 , wherein the step of heating the mixture to a solid phase reaction critical temperature comprises heating the mixture to a range from about 550° C. to about 800° C.

9. The method according to claim 7 , wherein the step of forming the solid electrolyte by using the solid electrolyte material further comprises:
conducting a cold pressing or hot pressing process on the solid electrolyte material to form the solid electrolyte.

10. The method according to claim 9 , wherein the step of forming the solid electrolyte by using the solid electrolyte material further comprises: mixing a binder with the solid electrolyte material before conducting the cold pressing or hot pressing process, wherein the mass percentage of the binder is about 10% to about 20% based on the total mass of the solid electrolyte, and the binder is selected from the group consisting of polypropylene, polyethylene, poly(ethylene oxide), polyphenylene oxide, polyvinylidene fluoride, a vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate ester, polyacrylic acid, polyacrylate salt, carboxymethyl cellulose sodium, polyvinylpyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, polyhexafluoropropylene, styrene-butadiene rubber and a combination thereof.

11. An electrochemical device, comprising:
a cathode;
an anode; and
a solid electrolyte, wherein the solid electrolyte comprises a solid electrolyte material being represented by a chemical formula of Li 1+2x−2y M y Ga 2+x P 1−x S 6 , wherein M is selected from a group consisting of Sr, Ba, Zn, Cd and a combination thereof, 0≤x≤0.2 and 0≤y≤0.05.

12. The electrochemical device according to claim 11 , wherein the solid electrolyte material belongs to a monoclinic crystal system and has a crystal structure of a diamond-like structure.

13. The electrochemical device according to claim 12 , wherein the crystal structure is composed of corner-sharing tetrahedral structural units.

14. The electrochemical device according to claim 12 , wherein a space group of the crystal structure of the solid electrolyte material is Cc, and primitive vectors of a unit cell of the crystal structure are a=11.373±0.5 Å, b=6.946±0.5 Å and c=11.401±0.5 Å.

15. The electrochemical device according to claim 11 , further comprising a binder, wherein a mass percentage of the binder is about 10% to about 20% based on a total mass of the solid electrolyte, and the binder is selected from a group consisting of polypropylene, polyethylene, poly(ethylene oxide), polyphenylene oxide, polyvinylidene fluoride, a vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate ester, polyacrylic acid, polyacrylate salt, carboxymethyl cellulose sodium, polyvinylpyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, polyhexafluoropropylene, styrene-butadiene rubber and a combination thereof.

16. The electrochemical device according to claim 11 , wherein the solid electrolyte material has ionic conductivity of about 10 −6 S/cm to about 10 −4 S/cm and a lithium ion migration barrier of less than about 0.4 eV.

17. An electronic device, comprising a electrochemical device, wherein the electrochemical device comprises:
a cathode;
an anode; and
a solid electrolyte, wherein the solid electrolyte comprises a solid electrolyte material being represented by a chemical formula of Li 1+2x−2y M y Ga 2+x P 1−x S 6 , wherein M is selected from a group consisting of Sr, Ba, Zn, Cd and a combination thereof, 0≤x≤0.2 and 0≤y≤0.05.

18. The electronic device according to claim 17 , wherein the solid electrolyte material belongs to a monoclinic crystal system and has a crystal structure of a diamond-like structure, the crystal structure is composed of corner-sharing tetrahedral structural units, a space group of the crystal structure of the solid electrolyte material is Cc, and primitive vectors of a unit cell of the crystal structure are a=11.373±0.5 Å, b=6.946±0.5 Å and c=11.401±0.5 Å.

19. The electronic device according to claim 17 , further comprising a binder, wherein a mass percentage of the binder is about 10% to about 20% based on a total mass of the solid electrolyte, and the binder is selected from group consisting of polypropylene, polyethylene, poly(ethylene oxide), polyphenylene oxide, polyvinylidene fluoride, a vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate ester, polyacrylic acid, polyacrylate salt, carboxymethyl cellulose sodium, polyvinylpyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, polyhexafluoropropylene, styrene-butadiene rubber and a combination thereof.

20. The electronic device according to claim 17 , wherein the solid electrolyte material has ionic conductivity of about 10'S/cm to about 10'S/cm and a lithium ion migration barrier of less than about 0.4 eV.

Assignees

• Ningde Amperex Technology Ltd

Inventors

• Zhou Molin
• Gu Feng
• Xu Leimin
• Zheng Jianming

Classifications

• C01P2002/77

  by unit-cell parameters, atom positions or structure diagrams · CPC title

• H01M2300/0068

  inorganic · CPC title

• H01M2300/0082

  Organic polymers · CPC title

• C01B17/42 Primary

  Sulfides or polysulfides of magnesium, calcium, strontium, or barium · CPC title

• C01P2006/40

  Electric properties · CPC title