Sulfide Solid Electrolyte Low-Temperature Conductivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sulfide solid electrolyte materials, particularly LiGePS-based ones, exhibit deteriorated Li ion conductivity in low-temperature environments, limiting battery performance.
Innovation Solution
A sulfide solid electrolyte material comprising Li, a divalent element such as Mg, Ca, or Zn, and S, with a specific crystal structure and substitution ratio, characterized by peaks in X-ray diffraction measurements, enhances Li ion conductivity at 0°C by optimizing the crystal phase ratio and divalent element substitution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LiGePS-based sulfide solid electrolyte material is used, then ion conductivity is improved, but Li ion conductivity deteriorates in low-temperature environment
Solution Approach 1:
The patent changes the chemical composition parameters by introducing divalent elements (Mg, Ca, Zn) to substitute part of the Li in LiGePS4, creating a new composition Li4-2δMgδGe1-xPxS4. This compositional parameter change modifies the crystal structure and electronic properties, enabling favorable Li ion conductivity at low temperatures while maintaining high ion conductivity overall.
Solution Approach 2:
The patent creates a composite sulfide solid electrolyte material by combining multiple elements (Li, Mg/Ca/Zn, Ge, P, S) in specific ratios. The composite material Li4-2δMgδGe1-xPxS4 integrates the advantages of different elements: Li provides ionic conductivity, divalent elements (Mg, Ca, Zn) provide structural stability and low-temperature performance, Ge and P contribute to crystal structure formation. This composite approach resolves the contradiction between high ion conductivity and low-temperature performance.
2Temperature
If substitution of Li with divalent element is increased, then low-temperature Li ion conductivity is improved, but excessive substitution may affect overall ion conductivity
Solution Approach 1:
The patent optimizes the substitution parameter δ within a specific range (0 < δ ≤ 0.5) to balance low-temperature performance and overall ion conductivity. By controlling the substitution amount rather than using full substitution, the patent achieves favorable Li ion conductivity at low temperatures while maintaining the structural integrity and high ion conductivity characteristics of the parent LiGePS4 material. This parameter optimization resolves the contradiction between improved low-temperature conductivity and maintained overall performance.
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 material achieves favorable Li ion conductivity in low-temperature environments, improving battery output and resistance, with the substitution of Li with divalent elements reducing activation energy and maintaining high ion conductivity.
Implementation Method 1
a sulfide solid electrolyte material with favorable Li ion conductivity in a low-temperature environment
Implementation Method 2
in X-ray diffraction measurement using a CuKα ray
Implementation Method 3
has a peak at a position of 2θ=29.58°±0.50° in X-ray diffraction measurement
Data Source
AI summary
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.