Sulfide solid electrolyte material, battery, and producing method for sulfide solid electrolyte material

• US 10,388,985 B2
• Filed: 02/05/2013
• Issued: 08/20/2019
• Est. Priority Date: 02/06/2012
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kato, Yuki, Otomo, Takamasa, Sakano, Mitsuru
• Primary Examiner(s): Cano, Milton I
• Assistant Examiner(s): Ojo-Amoo, Abibatu O
• Application Number:
  US14/375,624
• Publication Number:
  US 20150017548A1
• Time in Patent Office: 2,387 Days
• Field of Search: 429319, 429303, 429387
• CPC Class Codes: C01B 25/14 Sulfur, selenium, or tellurium compounds of phosphorus
• CPC Class Codes: C01G 17/006 Compounds containing, besides germanium, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01G 19/006 Compounds containing, besides tin, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/76 by a space-group or by other symmetry indications
• CPC Class Codes: C01P 2002/77 by unit-cell parameters, atom positions or structure diagrams
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01B 1/10 sulfides
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 4/621 Binders
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The main object of the present invention is to provide a sulfide solid electrolyte material having favorable ion conductivity and high stability against moisture. The present invention solves the above-mentioned problem by providing a sulfide solid electrolyte material comprising an M1 element (such as Li element), an M2 element (such as Ge element, Sn element and P element) and a S element, and having a peak at a position of 2θ=29.58°±0.50° in X-ray diffraction measurement using a CuKα ray, characterized in that when a diffraction intensity at the above-mentioned peak of 2θ=29.58°±0.50° is regarded as IA and a diffraction intensity at a peak of 2θ=27.33°±0.50° is regarded as IB, a value of IB/IA is less than 0.50, and the M2 contains at least P and Sn.

Claims

1. A sulfide solid electrolyte material comprising:

a composition of Li<sub>(4−

x)</sub>(M₂′

<sub>(1−

δ

)</sub>Sn_δ

)<sub>(1−

x)</sub>P_xS₄, where

M₂′

represents the element selected from the group consisting of Si, Ge, Ti, Zr, Nb and combinations thereof,

0<

δ

≤

1, and

0<

x<

1,

wherein

the sulfide solid electrolyte material has a peak at a position of 2θ

=29.58°

±

0.50°

in X-ray diffraction measurement using a CuKα

ray;

the sulfide solid electrolyte material satisfies conditions (i) or (ii);

(i) the sulfide solid electrolyte material does not have a peak at a position of 2θ

=27.33°

±

0.50°

in X-ray diffraction measurement using a CuKα

ray, or

(ii) when a diffraction intensity at the peak of 2θ

=29.58°

±

0.50°

is regarded as I_A and a diffraction intensity at a peak of 2θ

=27.33°

±

0.50°

is regarded as I_B, a value of I_BI_A is less than 0.50 but not 0.

2. The sulfide solid electrolyte material according to claim 1, wherein condition (ii) is satisfied.

3. The sulfide solid electrolyte material according to claim 1, wherein 0<

δ

<

1.

4. The sulfide solid electrolyte material according to claim 1, wherein 0.2≤

δ

≤

1.

5. The sulfide solid electrolyte material according to claim 1, wherein the sulfide solid electrolyte material has a composition of Li₍₄₋

x)Sn<sub>(1−

x)</sub>P_xS₄, where;

0.65≤

x≤

0.75.

6. The sulfide solid electrolyte material according to claim 1, wherein an a-axial length of a lattice constant is 8.70 Å

or more in a crystal phase having the peak at the position of 2θ

=29.58°

±

0.50°

.

11. A battery comprising

a cathode active material layer containing a cathode active material,

an anode active material layer containing an anode active material, and

an electrolyte layer formed between the cathode active material layer and the anode active material layer,

wherein at least one of the cathode active material layer, the anode active material layer and the electrolyte layer contains the sulfide solid electrolyte material according to claim 1.

13. A method for producing the sulfide solid electrolyte material according to claim 1, the method comprising:

synthesizing an amorphized ion conductive material by mechanical milling while using a raw material composition containing the M₁ element, the M₂ element, and the S element, and

obtaining the sulfide solid electrolyte material by heating the amorphized ion conductive material.

15. The sulfide solid electrolyte material according to claim 1, wherein condition (i) is satisfied.

16. The sulfide solid electrolyte material according to claim 1, wherein a molar fraction of the Li element is 3.35 or less based on a total molar fraction of P and the M₂′

element of 1.

17. The sulfide solid electrolyte material according to claim 1, wherein

0.65≤

x≤

0.75.

7. A sulfide solid electrolyte material comprising a crystal structure as a main body, the crystal structure includes:

an octahedron O composed of Li and S;

a tetrahedron T₁ composed of an M₂′

element, and, the tetrahedron T₁ and the octahedron O sharing an edge; and

a tetrahedron T₂ composed of an M₂′

element and, the tetrahedron T₂ and the octahedron O sharing a corner;

P is present in at least one of tetrahedron T₁ and tetrahedron T₂, and

Sn is present in at least one of tetrahedron T₁ and tetrahedron T₂;

wherein

the sulfide solid electrolyte material has a composition of Li<sub>(4−

x)</sub>(M₂′

<sub>(1−

δ

)</sub>Sn_δ

)<sub>(1−

x)</sub> P_xS₄, where

M₂′

represents the element selected from the group consisting of Si, Ge, Ti, Zr, Nb and combinations thereof, and may be the same or different in tetrahedron T₁ and tetrahedron T₂,

0<

δ

≤

1, and

0<

x<

1.

8. The sulfide solid electrolyte material according to claim 7, wherein 0<

δ

<

1.

9. The sulfide solid electrolyte material according to claim 7, wherein 0.2≤

δ

≤

1.

10. The sulfide solid electrolyte material according to claim 7, wherein an a-axial length of a lattice constant is 8.70 Å

or more in the crystal structure.

12. A battery comprising

a cathode active material layer containing a cathode active material,

an anode active material layer containing an anode active material, and

an electrolyte layer formed between the cathode active material layer and the anode active material layer,

wherein at least one of the cathode active material layer, the anode active material layer and the electrolyte layer contains the sulfide solid electrolyte material according to claim 7.

14. A method for producing the sulfide solid electrolyte material according to claim 7, the method comprising:

synthesizing an amorphized ion conductive material by mechanical milling while using a raw material composition containing the M₁ element, the M_2a element, the M_2b element, and the S element, and

obtaining the sulfide solid electrolyte material by heating the amorphized ion conductive material.