Boron-Modified Lithium Battery Anode for Fast-Charge Resistance Control
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Solution Overview
Problem
Rechargeable lithium batteries face challenges in achieving excellent rapid charge performance, particularly in reducing interfacial resistance and improving lithium diffusion rates.
Innovation Solution
A negative electrode active material layer comprising a boron compound, such as B2O3 or H3BO3, mixed with a silicon-based or carbon-based active material and an aqueous binder, is used to enhance charge transfer resistance and suppress the thickening of the SEI layer, improving high-rate charge and discharge characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional negative electrode materials are used, then the battery structure is simple, but the rapid charge performance is poor due to high interfacial resistance and slow lithium diffusion rates
Solution Approach 1:
The patent employs composite materials by combining boron compounds (B2O3 or H3BO3) with conventional negative electrode active materials (silicon-based or carbon-based materials). This composite structure reduces interfacial resistance and enhances lithium diffusion rates, thereby improving rapid charge performance without fundamentally changing the electrode architecture
Solution Approach 2:
The patent modifies the chemical composition parameters of the negative electrode by incorporating boron compounds at specific concentrations (0.1-3 wt% B2O3 or H3BO3). This parameter change alters the interfacial properties and lithium diffusion characteristics, enabling excellent rapid charge performance while maintaining structural simplicity
2Reliability
If the negative electrode active material layer is optimized for high-rate charge, then charge transfer resistance is reduced, but the SEI layer thickening is suppressed less effectively
Solution Approach 1:
The patent optimizes the boron compound concentration parameter (0.1-3 wt%) to achieve a balance between reducing charge transfer resistance and suppressing SEI layer thickening. The aqueous binder parameter is also optimized (1-5 wt%) to enhance the protective effect on the SEI layer while maintaining good charge transfer characteristics
Solution Approach 2:
The boron compound acts as an intermediary substance between the negative electrode active material and the electrolyte. It modifies the interfacial properties to reduce charge transfer resistance while simultaneously protecting the SEI layer from excessive thickening, thus mediating between charge performance and stability 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 use of boron compounds in the negative electrode active material layer reduces charge transfer resistance and improves lithium diffusion rates, resulting in excellent high-rate charge and discharge characteristics and increased thermal decomposition temperature, thereby enhancing battery performance and safety.
Implementation Method 1
improving lithium diffusion rates
Implementation Method 2
suppress the thickening of the SEI layer formed on a surface of the negative electrode during charging and discharging
Implementation Method 3
increased thermal decomposition temperature
Data Source
AI summary
Provided are a negative electrode for a rechargeable lithium battery and a rechargeable lithium battery including same, the negative electrode for a rechargeable lithium battery including a negative electrode active material layer which comprises a boron compound and negative electrode active material.