Coated Active Material for Low-Resistance Solid-State Battery Interfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery technologies face challenges in reducing interface resistance, particularly when a positive electrode active material and sulfide solid electrolyte come into contact during charging, leading to oxidative decomposition and increased resistance.
Innovation Solution
A coated active material is developed with a coating layer that has a supernatant transmittance of greater than 64% and less than 93%, using a coating material that includes Li, M1, and X1, where M1 is a metal element and X1 is a halogen, to prevent direct contact between the active material and solid electrolyte, thereby reducing interface resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating layer is applied to prevent oxidative decomposition, then reliability is improved, but device complexity increases
Solution Approach 1:
A coating layer comprising Li, M1, and X1 is applied to the surface of the positive electrode active material to serve as an intermediary barrier. This coating prevents direct contact between the active material and sulfide solid electrolyte, thereby preventing oxidative decomposition of the electrolyte during battery charging while maintaining reliable electrochemical performance.
2Power
If interface resistance is reduced through coating, then power is improved, but manufacturing precision requirements increase
Solution Approach 1:
The coating layer composition is optimized with specific parametric ranges: M1 content of 0.1-2.0 atomic ratios, X1 content of 0.1-2.0 atomic ratios, and controlled coating thickness. These parameter changes enable reduced interface resistance while maintaining manufacturability through standard coating processes.
Data Source
AI summary
The coated active material of the present disclosure includes an active material and a coating layer coating at least a part of the surface of the active material. The coated active material has a supernatant transmittance of greater than 64% and less than 93%. The supernatant transmittance is a transmittance of light with a wavelength of 550 nm measured for a supernatant liquid obtained by dispersing and precipitating the coated active material in a solvent. The supernatant liquid is placed in a quartz cell with a 10 mm optical path length and devoted to measurement of the transmittance.