LITHIUM IONIC CONDUCTOR, FABRICATION METHOD THEREFOR AND ALL-SOLID LITHIUM SECONDARY BATTERY

• US 20150340734A1
• Filed: 08/04/2015
• Published: 11/26/2015
• Est. Priority Date: 02/15/2013
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Homma, Kenji, Watanabe, Satoru
• Application Number:
  US14/817,338
• Publication Number:
  US 20150340734A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01B 1/06 mainly consisting of other non-metallic substances
• CPC Class Codes: H01B 1/10 sulfides
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A lithium ionic conductor (solid electrolyte) includes lithium (Li), phosphorus (P), boron (B) and sulfur (S) as constituent elements and includes a crystal structure including a crystal lattice of a monoclinic system.

Claims

1. A lithium ionic conductor, comprising lithium (Li), phosphorus (P), boron (B) and sulfur (S) as constituent elements and comprising a crystal structure including a crystal lattice of a monoclinic system.

2. The lithium ionic conductor according to claim 1, wherein the lithium ionic conductor has a composition represented by Li_3+3/4xB_xP₁₋

3/4xS₄ (0.9≦

x≦

1.1).

3. The lithium ionic conductor according to claim 1, wherein the lithium ionic conductor has, in an X-ray diffraction (CuKα

₁;

λ

=1.5405 Å

), a diffraction peak at 2θ

=18.83±

0.5 deg, 20.60±

0.5 deg, 28.52±

0.5 deg, 29.53±

0.5 deg, 34.09±

0.5 deg and 39.37±

0.5 deg.

4. The lithium ionic conductor according to claim 1, wherein the lithium ionic conductor has a crystal structure including a skeleton of a three-coordinated planar body centering on boron (B), a four-coordinated tetrahedron centering on boron (B) and another four-coordinated tetrahedron centering on phosphorus (P).

5. A lithium ionic conductor, comprising lithium (Li), phosphorus (P), boron (B) and sulfur (S) as constituent elements, and comprising, in an X-ray diffraction (CuKα

₁;

λ

=1.5405 Å

), a diffraction peak at 2θ

=18.83±

0.5 deg, 20.60±

0.5 deg, 28.52±

0.5 deg, 29.53±

0.5 deg, 34.09±

0.5 deg and 39.37±

0.5 deg.

6. A lithium ionic conductor, comprising a composition represented by Li_3+3/4xB_xP₁₋

3/4xS₄ (0.6≦

x≦

1.1).

7. An all-solid lithium secondary battery, comprising:

a positive electrode;

a negative electrode; and

a solid electrolyte that is provided between the positive electrode and the negative electrode, contains lithium (Li), phosphorus (P), boron (B) and sulfur (S) as constituent elements and has a crystal structure including a crystal lattice of a monoclinic system.

8. The all-solid lithium secondary battery according to claim 7, wherein the solid electrolyte has a composition represented by Li_3+3/4xB_xP₁₋

3/4xS₄ (0.9≦

x≦

1.1).

9. The all-solid lithium secondary battery according to claim 7, wherein the solid electrolyte has, in an X-ray diffraction (CuKα

₁;

λ

=1.5405 Å

), a diffraction peak at 2θ

=18.83±

0.5 deg, 20.60±

0.5 deg, 28.52±

0.5 deg, 29.53±

0.5 deg, 34.09±

0.5 deg and 39.37±

0.5 deg.

10. The all-solid lithium secondary battery according to claim 7, wherein the solid electrolyte has a crystal structure including a skeleton of a three-coordinated planar body centering on boron (B), a four-coordinated tetrahedron centering on boron (B) and another four-coordinated tetrahedron centering on phosphorus (P).

11. An all-solid lithium secondary battery, comprising:

a positive electrode;

a negative electrode; and

a solid electrolyte that is provided between the positive electrode and the negative electrode, contains lithium (Li), phosphorus (P), boron (B) and sulfur (S) as constituent elements and has, in an X-ray diffraction (CuKα

₁;

λ

=1.5405 Å

), a diffraction peak at 2θ

=18.83±

0.5 deg, 20.60±

0.5 deg, 28.52±

0.5 deg, 29.53±

0.5 deg, 34.09±

0.5 deg and 39.37±

0.5 deg.

12. An all-solid lithium secondary battery, comprising:

a positive electrode;

a negative electrode; and

a solid electrolyte provided between the positive electrode and the negative electrode and having a composition represented by Li_3+3/4xB_xP<sub>1−

3/4x</sub>S₄ (0.6≦

x≦

1.1).

13. A fabrication method for a lithium ionic conductor, comprising mixing lithium (Li), phosphorus (P), boron (B) and sulfur (S), melting the mixture by heating, and quenching the melted mixture to fabricate a solid electrolyte having a crystal structure including a crystal lattice of a monoclinic system.

14. The fabrication method for a lithium ionic conductor according to claim 13, wherein the solid electrolyte has a composition represented by Li_3+3/4xB_xP₁₋

3/4xS₄ (0.9≦

x≦

1.1).

15. The fabrication method for a lithium ionic conductor according to claim 13, wherein the solid electrolyte has, in an X-ray diffraction (CuKα

₁;

λ

=1.5405 Å

), a diffraction peak at 2θ

=18.83±

0.5 deg, 20.60±

0.5 deg, 28.52±

0.5 deg, 29.53±

0.5 deg, 34.09±

0.5 deg and 39.37±

0.5 deg.

16. The fabrication method for a lithium ionic conductor according to claim 13, wherein the solid electrolyte has a crystal structure including a skeleton of a three-coordinated planar body centering on boron (B), a four-coordinated tetrahedron centering on boron (B) and another four-coordinated tetrahedron centering on phosphorus (P).

17. A fabrication method for a lithium ionic conductor, comprising mixing lithium (Li), phosphorus (P), boron (B) and sulfur (S), melting the mixture by heating, and quenching the melted mixture to fabricate a solid electrolyte having, in X-ray diffraction (CuKα

₁;

λ

=1.5405 Å

), a diffraction peak at 2θ

=18.83±

0.5 deg, 20.60±

0.5 deg, 28.52±

0.5 deg, 29.53±

0.5 deg, 34.09±

0.5 deg and 39.37±

0.5 deg.

18. A fabrication method for a lithium ionic conductor, comprising mixing lithium (Li), phosphorus (P), boron (B) and sulfur (S), melting the mixture by heating, and quenching the melted mixture to fabricate a solid electrolyte having a composition represented by Li_3+3/4xB_xP₁₋

3/4xS₄ (0.6≦

x≦

1.33).