Coated Active Material for Oxidation-Stable Battery Interfaces
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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 and limitations in battery performance.
Innovation Solution
A coated active material is developed with a specific log differential pore volume at 1.2 μm, ranging from 55 μL/g to 152 μL/g, which includes a coating layer on the active material to prevent direct contact with the solid electrolyte, thereby reducing interface resistance and enhancing ion conductivity and oxidation stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sulfide solid electrolyte is used in the battery, then ion conductivity is improved, but oxidation resistance deteriorates during charging
Solution Approach 1:
An oxide coating layer is introduced as an intermediary between the sulfide solid electrolyte and the active material. This coating layer acts as a protective barrier that prevents direct contact and oxidative decomposition reactions, allowing the sulfide electrolyte to maintain its high ion conductivity while gaining oxidation resistance through the coating layer's protection
2Stability of the object's composition
If the coating layer completely covers the active material surface, then oxidation resistance is improved, but interface resistance increases
Solution Approach 1:
The coating layer is applied with controlled coverage rather than complete surface coverage. This local quality approach ensures that sufficient active material surface remains exposed to maintain good electrical contact and low interface resistance, while the coating layer provides oxidation protection at critical interfaces where it does contact the active material
3Stability of the object's composition
If the coating layer thickness is increased, then oxidation stability is improved, but ion conductivity deteriorates
Solution Approach 1:
The thickness of the oxide coating layer is precisely controlled within an optimal range. This parameter change approach ensures that the coating layer is thick enough to provide effective oxidation protection but thin enough to allow sufficient ion transport, balancing oxidation stability and ion conductivity requirements
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 effectively reduces interface resistance, improves battery output, and allows the use of solid electrolytes with inferior oxidation resistance, leading to enhanced energy density and charge/discharge efficiency.
Implementation Method 1
a coating layer coating at least a part of the surface of the active material
Implementation Method 2
enhancing ion conductivity
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 log differential pore volume of the coated active material at a pore diameter of 1.2 μm is within a range of greater than or equal to 55 μL/g and less than 152 μL/g. The electrode material of the present disclosure includes a coating material and a solid electrolyte. A battery of the present disclosure includes a positive electrode including the electrode material, a negative electrode, and an electrolyte layer disposed between the positive electrode and the negative electrode.