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

• US 9,929,433 B2
• Filed: 12/18/2013
• Issued: 03/27/2018
• Est. Priority Date: 01/17/2013
• Status: Active Grant

• Current Assignee: Tokyo Institute of Technology (National University Corporation Tokyo Institute of Technology), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Tokyo Institute of Technology (National University Corporation Tokyo Institute of Technology), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kanno, Ryoji, Hirayama, Masaaki, Kato, Yuki, Yamasaki, Hisatsugu
• Primary Examiner(s): Slifka, Sarah A.
• Assistant Examiner(s): Greso, Aaron J
• Application Number:
  US14/760,344
• Publication Number:
  US 20150357673A1
• Time in Patent Office: 1,560 Days
• CPC Class Codes: H01B 1/10 sulfides
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The problem is to provide a sulfide solid electrolyte material with favorable Li ion conductivity in a low-temperature environment. The problem is overcome by providing a sulfide solid electrolyte material comprising an M₁ element (such as an Li element and an Mg element), an M₂ element (such as a Ge element and a P element) and a S element, 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, does not have a peak at a position of 2θ=27.33°±0.50° or slightly having the peak, and a substituted amount δ(%) of the divalent element in the M₁ element is in such a range that the sulfide solid electrolyte material exhibits higher Li ion conductance at 0° C. than the case of δ=0.

Claims

1. A sulfide solid electrolyte material comprising an M₁ element, an M₂ element and a S element,

the M₁ being a combination of Li and a divalent element of at least one kind selected from the group consisting of Mg, Ca and Zn, and

the M₂ being at least one kind selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V and Nb,

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,

does not have a peak at a position of 2θ

=27.33°

±

0.50°

in X-ray diffraction measurement using a CuKα

ray, or

when diffraction intensity at the peak of 2θ

=29.58°

±

0.50°

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

=27.33°

±

0.50°

is regarded as I_B in a case of having a peak at the position of 2θ

=27.33°

±

0.50°

, a value of I_B/I_A is less than 0.50, and

a substituted amount δ

(%) of the divalent element is in such a range that the sulfide solid electrolyte material exhibits higher Li ion conductance at 0°

C. than a case of δ

=0, and satisfies 0<

δ

(%)<

1;

substituted amount δ

(%)=2X_1B/(X_1A+2X_1B)*100

(X_1A is a molar fraction of the Li in the M₁ and X_1B is a molar fraction of the divalent element in the M₁).

3. 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.

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

an ion conductive material synthesizing step of 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

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

7. The sulfide solid electrolyte material of claim 1,

wherein the M_2a is P, and the M_2b is Ge.

2. A sulfide solid electrolyte material having an octahedron O composed of an M₁ element and a S element, a tetrahedron T₁ composed of an M_2a element and a S element, and a tetrahedron T₂ composed of an M_2b element and a S element, the tetrahedron T₁ and the octahedron O sharing an edge, and the tetrahedron T₂ and the octahedron O containing a crystal structure sharing a corner as a main body,

wherein the M₁ is a combination of Li and a divalent element of at least one kind selected from the group consisting of Mg, Ca and Zn,

the M_2a and the M_2b are each independently at least one kind selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V and Nb, and

a substituted amount δ

(%) of the divalent element is in such a range that the sulfide solid electrolyte material exhibits higher Li ion conductance at 0°

C. than a case of δ

=0, and satisfies 0<

δ

(%)<

1;

substituted amount δ

(%)=2X_1B/(X_1A+2X_1B)*100

(X_1A is a molar fraction of the Li in the M₁ and X_1B is a molar fraction of the divalent element in the M₁).

4. 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 2.

6. A producing method for a sulfide solid electrolyte material, the sulfide solid electrolyte material being the sulfide solid electrolyte material according to claim 2, the producing method comprising:

an ion conductive material synthesizing step of 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

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