Solid Electrolyte Surface Roughness for Faster All-Solid-State Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
All-solid-state batteries in the related art suffer from insufficient ionic conductivities, leading to low discharge capacity at high current densities and poor rate characteristics.
Innovation Solution
A solid electrolyte material with a surface ten-point average roughness of 20 nm or more and 1500 nm or less, comprising at least one of halide-based or sulfide-based solid electrolytes, is used, with an average thickness of 2.0 μm or more, to enhance ionic conductivity and rate characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solid electrolytes with conventional smooth surfaces are used, then manufacturing is easier, but ionic conductivity is insufficient and rate characteristics are poor
Solution Approach 1:
The invention changes the surface roughness parameter of the solid electrolyte from smooth (conventional) to controlled roughness (Rz 20-1500 nm) to improve ionic conductivity and rate characteristics while maintaining manufacturability through standardized surface treatment processes
Solution Approach 2:
The surface roughening treatment is performed in advance during the solid electrolyte manufacturing process, before battery assembly, to pre-establish the optimal surface conditions for high ionic conductivity and prevent electrical deterioration during battery operation
2Strength
If solid electrolyte thickness is increased to improve mechanical strength, then reliability improves, but ionic conductivity decreases
Solution Approach 1:
The invention optimizes the thickness parameter to a specific range (2.0 μm or more) that balances mechanical strength requirements with ionic conductivity performance, preventing both mechanical failure and electrical deterioration
Solution Approach 2:
The invention applies different surface qualities to different regions - the bulk maintains sufficient thickness for mechanical strength while the surface is roughened to enhance ionic conductivity, creating local optimization in both mechanical and electrical properties
Data Source
AI summary
A solid electrolyte material has a pair of surfaces which face each other and includes at least one of a predetermined halide-based solid electrolyte or a predetermined sulfide-based solid electrolyte, in which a surface ten-point average roughness RzJIS of at least one of the pair of surfaces falls in the range from 20 nm or more and 1500 nm or less.