LGPS Sulfide Solid Electrolyte Composition for High Ion Conductivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sulfide solid electrolytes for solid-state batteries lack high ion conductivity, which is essential for improving battery performance.
Innovation Solution
A sulfide solid electrolyte with a LGPS-type crystal phase containing Li, P, and S, along with elements like Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, and Nb, where the half value width of a peak in 31P-NMR measurement and the rate of impurity phase satisfy specific formulas, enhancing ion conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sulfide solid electrolytes are used, then the battery structure can be simplified with solid electrolyte, but the ion conductivity is insufficient for high performance
Solution Approach 1:
The patent changes the chemical composition parameters of the sulfide solid electrolyte by incorporating specific elements (Li, M1, M2, P, S) in controlled ratios defined by formulas (1) and (2). This compositional parameter optimization enables the electrolyte to achieve ion conductivity of 5.0 mS/cm or more at 25°C, resolving the contradiction between reliability and productivity.
Solution Approach 2:
The patent creates a composite sulfide solid electrolyte system by combining multiple elements (Li, M1 from groups 13-16, M2 from groups 1-12 or 14-16, P, and S) in a unified crystal structure. This composite approach leverages the synergistic effects of different elements to achieve high ion conductivity while maintaining structural stability, thereby improving battery performance.
2Ease of manufacture
If impurity phase is present in the sulfide solid electrolyte, then manufacturing tolerance is increased, but ion conductivity decreases
Solution Approach 1:
The patent converts the harmful effect of impurity phases into a beneficial relationship by establishing a mathematical tolerance range (formulas (1) and (2)) that defines the maximum acceptable impurity level (x%) corresponding to the required half value width (y ppm). This allows manufacturers to produce electrolytes with acceptable performance variations while ensuring ion conductivity remains above 5.0 mS/cm, thus converting manufacturing variability from a harm into a controlled parameter.
Data Source
AI summary
A main object of the present disclosure is to provide a sulfide solid electrolyte with high ion conductivity. The present disclosure achieves the object by providing a sulfide solid electrolyte including a LGPS-type crystal phase containing a Li element, an M element, a P element, and a S element, wherein: the M element is at least one kind or more of an element selected from Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb; and in a 31P-NMR measurement, when y (ppm) designates a half value width of a peak having an apex at a position of 77 ppm±1 ppm, and x (%) designates a rate of impurity phase measured, the sulfide solid electrolyte satisfies a below formula (1):y≤−0.0431x+4.28 (1).