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

• US 10,305,140 B2
• Filed: 05/13/2015
• Issued: 05/28/2019
• Est. Priority Date: 05/15/2014
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kato, Yuki, Ohtomo, Takamasa
• Primary Examiner(s): Barrow, Amanda J
• Application Number:
  US14/710,987
• Publication Number:
  US 20150333367A1
• Time in Patent Office: 1,476 Days
• Field of Search: None
• CPC Class Codes: C01B 17/22 Alkali metal sulfides or polysulfides
• CPC Class Codes: C01B 25/14 Sulfur, selenium, or tellurium compounds of phosphorus
• 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: Y02E 60/10 Energy storage using batteries

Abstract

An object of the present invention is to provide a sulfide solid electrolyte material having satisfactory ion conductivity. In the present invention, the above object is solved by providing a sulfide solid electrolyte material comprising a Li element, a Si element, a P element, a S element, and an X element (in which X represents at least one of F, Cl, Br and I), the sulfide solid electrolyte material having a crystal phase B having a peak at the position of 2θ=30.12°±1.00° measured by X-ray diffractometry using CuKα ray.

Claims

1. A sulfide solid electrolyte material, comprising a Li element, a Si element, a P element, a S element, and an X element (in which X represents at least one of F, Cl, Br and I),

wherein the sulfide solid electrolyte material has a crystal phase B that has peaks at positions of 2θ

=15.60°

±

1.00°

, 18.04°

±

1.00°

, 25.60°

±

1.00°

, 30.12°

±

1.00°

, and 31.46°

±

1.00°

, and that does not have a peak at a position of 27.33°

±

1.00°

, measured by X-ray diffractometry using CuKα

ray,

wherein when the diffraction intensity of the peak of 2θ

=30.12°

±

1.00°

is designated as I₁, and the diffraction intensity of the peak of 2θ

=31.46°

±

1.00°

is designated as I₂, a value of a ratio I₁/I₂ is in a range of 1.4 to 2.8, and

wherein the sulfide solid electrolyte material has a composition of y(LiX)·

(100−

y) (Li_(4-x)Si_(1-x)P_xS₄), in which x satisfies the relationship;

0.55≤

×

≤

0.7, and y satisfies the relationship;

20≤

y ≤

60.

2. The sulfide solid electrolyte material according to claim 1, wherein the sulfide solid electrolyte material has a crystal phase A having a peak at a position of 2θ

=29.58°

±

1.00°

measured by X-ray diffractometry using CuKα

ray.

3. The sulfide solid electrolyte material according to claim 2, wherein when a diffraction intensity of the peak at 2θ

=29.58°

±

1.00°

is designated as I_A, and a diffraction intensity of the peak at 2θ

=30.12°

±

1.00°

is designated as I_B, a value of a ratio I_A/I_B is 1.3 or less.

4. The sulfide solid electrolyte material according to claim 1, wherein x satisfies the relationship:

x =0.6.

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

represented by the following formula satisfies the relationship;

8.2≤

η

≤

9.5;

η

=Σ

_I=1^N V_I m_I/Σ

m_α

,

in which v_I represents a valence of cationic elements comprising the Li element, the Si element, and the P element;

m_I represents a number of moles of the cationic element;

N represents a total number of cation species included in the sulfide solid electrolyte material; and

m_α

represents a number of moles of cationic elements excluding the Li element.

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

represented by the following formula satisfies the relationship;

3.6≤

γ

≤

4.9;

γ

=m_Li/Σ

m_α

,

in which m_Li represents a number of moles of the Li element; and

m_α

represents a number of moles of cationic elements comprising the Si element and the P element, and excluding the Li element.

7. The sulfide solid electrolyte material according to claim 1, wherein X represents Cl.

8. 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.

9. A method for producing the sulfide solid electrolyte material according to claim 1,

comprising steps of:

an ion conductive material synthesis step of synthesizing an amorphized ion conductive material by mechanical milling using a raw material composition containing a constituent component of the sulfide solid electrolyte material; and

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