Solid-State Battery Cathode Interface for Low-Resistance Sulfide Electrolytes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid-state batteries using sulfide-based solid electrolytes face issues with high resistance and excessive heat generation due to decreased ion conductivity when the entire surface is oxidized.
Innovation Solution
A solid-state battery design featuring a high oxygen concentration layer on the contact surface between the oxide-based cathode active material and the sulfide-based solid electrolyte, formed by charging the battery in an oxygen-free atmosphere until the cathode potential exceeds its maximum value and storing it at a controlled temperature, which reduces heat generation and resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the whole surface of sulfide-based solid electrolyte is oxidized, then hydrogen sulfide generation is reduced and capacity-keeping rate is improved, but ion conductivity is largely decreased and resistance increases
Solution Approach 1:
The patent applies local quality by forming a high oxygen concentration layer only at the contact surface between the sulfide-based solid electrolyte and the oxide-based cathode active material, rather than oxidizing the entire surface. This localized oxidation approach maintains high ion conductivity in the bulk electrolyte while providing the protective oxygen-rich interface needed to prevent hydrogen sulfide generation and maintain capacity-keeping rate.
2Object-affected harmful factors
If the whole surface of sulfide-based solid electrolyte is oxidized, then hydrogen sulfide generation is reduced, but heat generation amount increases
Solution Approach 1:
The patent reduces heat generation by limiting oxidation to only the necessary contact surface area between the electrolyte and cathode material. This localized approach provides sufficient protection against hydrogen sulfide generation while minimizing the thermal side effects associated with extensive surface oxidation.
Solution Approach 2:
The patent applies partial action by providing just enough oxidation at the contact surface to prevent hydrogen sulfide generation, rather than oxidizing the entire surface. The high oxygen concentration layer is formed with controlled thickness and distribution, achieving the minimum necessary protective effect while avoiding excessive heat generation.
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 approach results in a solid-state battery with reduced heat generation and lower resistance, effectively addressing the limitations of sulfide-based electrolytes by selectively forming a high oxygen concentration layer, thereby enhancing battery performance.
Implementation Method 1
the sulfide-based solid electrolyte comprises a high oxygen concentration layer on a contact surface with the oxide-based cathode active material, the high oxygen concentration layer having a higher oxygen element concentration than other parts except the contact surface
Data Source
AI summary
A solid-state battery having a low heat generation amount and low resistance, and a method for producing the same. The solid-state battery is a solid-state battery comprising: a cathode comprising a cathode layer that contains an oxide-based cathode active material, an anode comprising an anode layer that contains an anode active material, and a solid electrolyte layer being disposed between the cathode layer and the anode layer and containing a solid electrolyte, wherein at least any one of the cathode layer and the solid electrolyte layer contains a sulfide-based solid electrolyte, and wherein the sulfide-based solid electrolyte comprises a high oxygen concentration layer on a contact surface with the oxide-based cathode active material, the high oxygen concentration layer having a higher oxygen element concentration than other parts except the contact surface.