Resistance-Reduction Coating for Solid-State Battery Cathodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
All solid-state lithium secondary batteries face increased interfacial resistance due to reactions between the cathode active material and solid electrolyte, leading to reduced battery performance and output.
Innovation Solution
A cathode active material coated with a resistance-reduction coating layer that contains no fine particles of the cathode active material, preventing the formation of high-resistance portions and ensuring lithium-ion conductivity, thereby reducing the resistance between the cathode active material and the solid electrolyte.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cathode active material is coated with a coating layer to prevent reaction with solid electrolyte, then the interfacial resistance is reduced, but fine particles of cathode active material may be mixed into the coating layer causing high-resistance portions to form
Solution Approach 1:
The coating layer is designed with specific local properties: it is formed to contain substantially no fine particles of cathode active material, creating a localized quality difference between the coating layer and the bulk cathode mixture. This local quality control prevents high-resistance portions while maintaining the protective function against solid electrolyte reaction.
Solution Approach 2:
The invention changes the compositional parameter of the coating layer by controlling the absence of fine particles of cathode active material. This parameter change (from containing fine particles to substantially free of fine particles) transforms the coating layer from potentially harmful to beneficial, reducing interfacial resistance without forming high-resistance portions.
2Stability of the object's composition
If a coating layer is applied to the cathode active material surface, then reaction with solid electrolyte is prevented, but the output of the battery is reduced due to increased resistance
Solution Approach 1:
The coating layer exhibits local quality by being substantially free of fine particles of cathode active material, creating a distinct compositional region that maintains low resistance. This localized quality control allows the coating to prevent solid electrolyte reaction while maintaining electrical conductivity for high battery output.
Solution Approach 2:
The invention uses a composite structure consisting of the coating layer formed from the cathode mixture on the cathode active material surface. This composite material approach combines the protective function against solid electrolyte reaction with the electrical conductivity needed for high power output, resolving the contradiction between stability and power.
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 solution effectively suppresses the reduction of battery output by minimizing interfacial resistance and maintaining lithium-ion conductivity, enhancing the performance of all solid-state lithium secondary batteries.
Implementation Method 1
the resistance-reduction coating layer contains substantially no fine particles of the cathode active material... reducing the resistance to movement of lithium ions between the cathode active material and the solid electrolyte
Data Source
AI summary
In a cathode active material coated with a resistance-reduction coating layer for preventing formation of a resistive layer, which has a cathode active material and a resistance-reduction coating layer with which a surface of the cathode active material is coated, the resistance-reduction coating layer contains substantially no fine particles of the cathode active material.