Coated Active Material for Oxidation-Resistant Battery Interfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery technologies face challenges in reducing interface resistance, particularly when a sulfide solid electrolyte is oxidatively decomposed during charging, leading to inefficiencies in ion conductivity and battery performance.
Innovation Solution
A coated active material is developed with a coating layer containing a first coating material, where the supernatant NV rate is less than 23%, preventing direct contact between the active material and solid electrolyte and enhancing ion conductivity and oxidation resistance, thereby reducing interface resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a sulfide solid electrolyte is used in the battery, then high ion conductivity is achieved, but oxidation resistance deteriorates during charging
Solution Approach 1:
A coating layer comprising an oxide solid electrolyte is formed on the surface of the active material to serve as an intermediary barrier. This coating layer prevents direct contact between the sulfide solid electrolyte and the active material, thereby preventing oxidative decomposition of the sulfide solid electrolyte during charging while maintaining high ion conductivity through the coating layer.
2Reliability
If the active material surface is coated to prevent oxidation, then oxidation resistance is improved, but interface resistance increases
Solution Approach 1:
The coating layer is designed with controlled thickness (5 nm to 500 nm) and specific compositional parameters to optimize both oxidation protection and ion conductivity. By adjusting these parameters, the coating provides sufficient oxidation barrier while maintaining low interface resistance for efficient ion transport.
Solution Approach 2:
The battery structure combines the sulfide solid electrolyte (for high ion conductivity) with the oxide solid electrolyte coating (for oxidation resistance) to create a composite system that achieves both high ion conductivity and oxidation resistance simultaneously, eliminating the trade-off between these two properties.
3Reliability
If a coating layer is applied to the active material, then oxidation resistance is improved, but manufacturing complexity increases
Solution Approach 1:
The coating layer is formed on the active material surface before assembling the battery components. This preliminary coating action ensures that the oxidation protection is already in place before the sulfide solid electrolyte is introduced, simplifying the overall manufacturing process by preventing oxidation issues from arising during subsequent assembly and operation.
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 coated active material significantly reduces interface resistance in batteries, improving ion conductivity and output properties, even when using sulfide or halide solid electrolytes with inferior oxidation resistance.
Implementation Method 1
a coating layer coating at least a part of the surface of the active material... preventing direct contact between the active material and solid electrolyte
Implementation Method 2
enhancing ion conductivity... improving ion conductivity and output properties
Implementation Method 3
enhancing... oxidation resistance... even when using sulfide or halide solid electrolytes with inferior oxidation resistance
Data Source
AI summary
A 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 coating layer includes a first coating material. The coated active material has a supernatant NV rate of less than 23%, where the supernatant NV rate is a ratio of the NV value of a supernatant liquid to the mass content ratio of the first coating material in a dispersing liquid obtained by dispersing the coated active material in a solvent, and the NV value of the supernatant liquid is a ratio of the mass of a non-volatile component to the mass of the supernatant liquid obtained by precipitating the coated active material by leaving the dispersing liquid to stand.