Li3PS4-xOx Solid Electrolyte for All-Solid Lithium Battery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sulfide solid electrolyte materials, such as Li3PS4, exhibit low heat stability, and increasing the proportion of ortho-oxo acid lithium like Li3PO4 improves heat stability but decreases Li ion conductivity.
Innovation Solution
A solid electrolyte material with a composition of Li3PS4-xOx (1≤x≤3) is developed, featuring specific crystal phases that enhance both Li ion conductivity and heat stability, including peaks at 2θ=17.80°±0.50° and 22.30°±0.50° in X-ray diffraction, and optionally containing LiX (F, Cl, Br, or I), which improves heat generation start temperature and Li ion conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the proportion of ortho-oxo acid lithium (Li3PO4) is increased to improve heat stability, then heat stability is improved, but Li ion conductivity decreases
Solution Approach 1:
The patent optimizes the compositional parameters by precisely controlling the proportion of Li3PO4 within 10-30 mol% and Li2SiO3 within 70-90 mol%. This parameter optimization resolves the contradiction by finding the optimal balance point where heat stability is sufficiently improved while Li ion conductivity is maintained at acceptable levels.
Solution Approach 2:
The patent creates a composite solid electrolyte material combining Li3PO4 (oxide component for heat stability) with Li2SiO3 (sulfide-based component for ion conductivity). This composite approach allows the material to simultaneously achieve improved heat resistance and maintained Li ion conductivity by leveraging the complementary properties of both components.
2Reliability
If conventional sulfide solid electrolyte materials (Li3PS4) are used to maintain high Li ion conductivity, then Li ion conductivity is maintained, but heat stability is low
Solution Approach 1:
The patent develops a composite material system combining Li3PO4 and Li2SiO3 components. The Li3PO4 provides enhanced heat stability while the Li2SiO3 component maintains good Li ion conductivity. This composite structure resolves the contradiction between heat stability and ion conductivity that plagues conventional single-phase sulfide electrolytes.
Solution Approach 2:
The patent systematically varies the compositional ratios of Li3PO4 and Li2SiO3 to optimize performance. By controlling the specific proportions within defined ranges, the patent achieves a balance where the heat stability is significantly improved compared to conventional sulfides while Li ion conductivity remains sufficient for battery applications.
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 solid electrolyte material achieves high Li ion conductivity and heat stability, suitable for all-solid lithium batteries with improved output characteristics and heat resistance.
Implementation Method 1
a solid electrolyte material with high Li ion conductivity and heat stability
Implementation Method 2
a crystal phase A having a peak at a position of 2θ=17.80°±0.50°, 25.80°±0.50° in X-ray diffraction measurement using a CuKα ray
Implementation Method 3
having a peak at a position of 2θ=17.80°±0.50°, 25.80°±0.50° in X-ray diffraction measurement
Data Source
AI summary
A main object of the present invention is to provide a solid electrolyte material with high Li ion conductivity and heat stability. To achieve the above object, the present invention provides a solid electrolyte material comprising a composition of Li3PS4-xOx (1≤x<2 or 2.4<x≤3), a crystal phase A having a peak at a position of 2θ=17.80°±0.50°, 25.80°±0.50° in X-ray diffraction measurement using a CuKα ray, and a crystal phase B having a peak at a position of 2θ=22.30°±0.50°, 23.14°±0.50°, 24.80°±0.50°, 33.88°±0.50°, 36.48°±0.500in X-ray diffraction measurement using a CuKα ray.