LiNbO-Coated Cathode Material for Low-Resistance Solid-State Batteries
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Solution Overview
Problem
The interface resistance between the electrode active material and the sulfide solid electrolyte in solid-state batteries increases during charging and discharging, limiting the transportation of lithium ions, which is a challenge in improving battery performance.
Innovation Solution
An active material with specific peak structures in the range of 0.145 nm to 0.185 nm and 0.28 nm to 0.31 nm in the radial distribution function, coated with a LiNbO layer, is used to reduce interface resistance with the sulfide solid electrolyte.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sulfide solid electrolyte is used in a solid-state battery, then safety is improved by eliminating flammable organic solvents, but interface resistance between the electrode active material and the sulfide solid electrolyte increases, restricting lithium ion transport
Solution Approach 1:
The patent applies the intermediary principle by introducing a coating layer comprising LiNbO3 on the surface of the electrode active material. This coating layer acts as a mediator between the electrode active material and the sulfide solid electrolyte, preventing direct harmful reactions while maintaining good contact. The LiNbO3 coating specifically suppresses the formation of resistive layers at the interface, thereby reducing interface resistance and improving lithium ion transport without compromising the safety benefits of using sulfide solid electrolyte.
Solution Approach 2:
The patent employs composite materials by creating a structured system consisting of the electrode active material core combined with a LiNbO3 coating shell. This composite structure allows the inner core to provide the necessary electrochemical activity while the outer coating provides protective functions, including suppressing interfacial reactions with the sulfide solid electrolyte. The composite design enables simultaneous achievement of high safety and low interface resistance.
2Ease of manufacture
If the electrode active material and sulfide solid electrolyte are brought into direct contact, then battery assembly is simplified, but they react with each other to form a resistive layer at the interface
Solution Approach 1:
The LiNbO3 coating serves as an intermediary layer that prevents direct contact and reaction between the electrode active material and the sulfide solid electrolyte. This coating layer is applied to the surface of the electrode active material before assembly, creating a protective barrier that eliminates harmful interfacial reactions while maintaining the simplicity of the battery assembly process. The coating can be applied through conventional methods such as sputtering, chemical vapor deposition, or solution-based coating.
Solution Approach 2:
The patent applies preliminary action by pre-coating the electrode active material with LiNbO3 before assembling the battery. This preliminary protective measure ensures that the resistive layer formation is prevented from the outset, rather than attempting to address it after the fact. The coating is applied in advance to the electrode active material surface, creating a stable interface that resists degradation during battery 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 active material effectively reduces interface resistance, enhancing battery performance by improving lithium ion transport and stability.
Implementation Method 1
exhibiting at least one peak in a range of from 0.145 nm to 0.185 nm and at least one peak in a range of from 0.28 nm to 0.31 nm in a radial distribution function obtained through measurement of an X-ray absorption fine structure of the active material
Data Source
AI summary
Disclosed is an active material that can reduce an interface resistance with a sulfide solid electrolyte and improve the battery performance. The active material exhibits at least one peak in the range of from 0.145 nm to 0.185 nm and at least one peak in the range of from 0.28 nm to 0.31 nm in a radial distribution function obtained through measurement of an X-ray absorption fine structure of the active material. The active material is for use in a solid-state battery. The active material preferably has a core particle, and a coating layer located on the surface of the core particle.