Sulfide Solid Electrolyte Ion Conductivity via Crystal Phase Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current solid electrolyte materials for lithium batteries lack favorable ion conductivity, which hinders the development of high-output batteries.

Innovation Solution

A sulfide solid electrolyte material with a specific composition of LixSiyPzS1-x-y-z-wXw (0.37≤x≤0.40, 0.054≤y≤0.078, 0.05≤z≤0.07, 0≤w≤0.05, where X is F, Cl, Br, or I) is developed, characterized by the absence or minimal presence of a crystal phase B, ensuring high ion conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If crystal phase B is present in sulfide solid electrolyte material, then material stability is improved, but ion conductivity deteriorates

Engineering Contradiction:

Improvematerial stabilityVSAvoidion conductivity

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent applies parameter changes by controlling the crystal phase composition parameter (IB/IA ratio ≤ 0.6) to suppress crystal phase B while maintaining material stability, thereby achieving high ion conductivity

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The sulfide solid electrolyte material achieves favorable ion conductivity, enabling the production of high-output batteries with improved safety and reduced production costs by eliminating the need for flammable organic solvents.

Implementation Method 1

A solid electrolyte material with favorable ion conductivity has been demanded from the viewpoint of achieving higher output of a battery

Methodology Applied

Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 2

the sulfide solid electrolyte material has a crystal phase A having a peak at a position of 2θ=29.58°±1.00° in X-ray diffraction measurement using a CuKα ray

Methodology Applied

Scientific EffectX-ray diffraction: Bragg Diffraction

Data Source

PatentUS10333170B2Sulfide solid electrolyte material, battery, and method for producing sulfide solid electrolyte material

Publication Date: 2019.06.25 TOYOTA JIDOSHA KK

AI summary

An object of the present invention is to provide a sulfide solid electrolyte material with favorable ion conductivity. In the present invention, the above object is achieved by providing a sulfide solid electrolyte material comprising a composition of LixSiyPzS1-x-y-z-wXw (0.37≤x≤0.40, 0.054≤y≤0.078, 0.05≤z≤0.07, 0≤w≤0.05, and X is at least one of F, Cl, Br, and I), characterized in that the sulfide solid electrolyte material has a crystal phase A having a peak at a position of 2θ=29.58°±1.00° in X-ray diffraction measurement using a CuKα ray, the sulfide solid electrolyte material does not have a crystal phase B having a peak at a position of 2θ=30.12°±1.00° in X-ray diffraction measurement using a CuKα ray, or slightly has the crystal phase B.