Coated Negative Electrode Material for Stable Li-Ion Battery Interfaces
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Solution Overview
Problem
Lithium ion batteries face challenges in improving cycle performance and first cycle coulombic efficiency due to irreversible consumption of lithium ions at the interface between the negative electrode and electrolyte, which affects their overall performance.
Innovation Solution
A negative electrode active material is developed with a coating layer comprising polymethyl methacrylate, sodium maleate, or oleic diethanolamide borate, applied to the surface of the negative electrode active substance, which inhibits interfacial reactions and reduces irreversible ion consumption, enhancing cycle performance and coulombic efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating layer is applied to the negative electrode active substance surface, then cycle performance and first cycle coulombic efficiency are improved, but device complexity increases
Solution Approach 1:
The coating layer is applied in advance to the negative electrode active substance surface before battery operation. This preliminary action prevents structural damage and inhibits interfacial reactions between the electrolyte and electrode material during subsequent cycling, thereby improving cycle performance and first cycle coulombic efficiency without requiring complex operational controls
Solution Approach 2:
A thin coating layer (5-50 nm) is formed on the negative electrode active substance surface. This thin film structure provides protective functions including reducing structural damage from lithium ion insertion/extraction and inhibiting electrolyte decomposition, while maintaining lithium ion transmission efficiency and avoiding excessive complexity
2Reliability
If the coating layer thickness is increased, then the inhibition of interfacial reaction is improved, but lithium ion transmission rate decreases
Solution Approach 1:
The coating layer thickness is optimized to a specific range of 5-50 nm. This parameter optimization ensures sufficient coverage to inhibit interfacial reactions between the electrolyte and electrode material, while maintaining adequate lithium ion transmission rate. The thickness is carefully controlled to balance protective function with ion conductivity
Solution Approach 2:
The coating layer provides localized protection at the critical electrode-electrolyte interface. By concentrating the protective function at this specific location rather than throughout the entire electrode structure, the coating effectively inhibits interfacial reactions while minimizing impact on bulk lithium ion transmission properties
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 coating layer improves the cycle performance and first cycle coulombic efficiency of lithium ion batteries by reducing structural damage and enhancing lithium ion deintercalation efficiency, forming a stable solid electrolyte interface film.
Implementation Method 1
inhibit the interfacial reaction between an electrolyte and the surface of the negative electrode plate
Implementation Method 2
improve the deintercalation efficiency of the lithium ions
Data Source
AI summary
A negative electrode active material and a preparation method therefore, and a related device are disclosed. The negative electrode active material comprises a negative electrode active substance and a coating layer. The coating layer is coated on the surface of the negative electrode active substance, and the coating layer comprises at least one of polymethyl methacrylate, sodium maleate, and oleic acid diethanolamide borate. The cycle performance and the initial coulombic efficiency of batteries are improved.