Negative Electrode Composition for Lithium Battery Volumetric Expansion
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Solution Overview
Problem
Lithium batteries used in high-temperature applications, such as electric vehicles, face challenges in maintaining discharge capacity and lifespan due to the volumetric expansion of negative active materials during charging and discharging, which affects their performance and longevity.
Innovation Solution
A negative electrode composition comprising a metal/metalloid-containing active material, an acrylate-based binder, and guanidine carbonate, where the acrylate-based binder includes lithium polyacrylate and the guanidine carbonate enhances adhesion and electric conductivity, helping to manage volumetric changes and improve cycle properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If metal/metalloid negative active materials are used to increase capacity, then energy density is improved, but volumetric expansion during charging/discharging worsens lifespan
Solution Approach 1:
The patent applies beforehand cushioning by incorporating a binder composition containing acrylate-based binder and guanidine carbonate that anticipates and compensates for the volumetric expansion of metal/metalloid negative active materials during charging and discharging cycles. This binder system is designed to accommodate expansion before it causes damage, thereby preventing electrode degradation and maintaining battery lifespan while utilizing high-capacity metal/metalloid materials.
2Ease of manufacture
If conventional binder systems are used, then manufacturing simplicity is maintained, but adhesion properties and cycle stability deteriorate
Solution Approach 1:
The patent applies composite materials by creating a binder composition that combines acrylate-based binder with guanidine carbonate in specific ratios (where guanidine carbonate is 3-30 parts by weight per 100 parts by weight of acrylate-based binder). This composite binder system leverages the adhesive properties of acrylate and the conductive and stabilizing effects of guanidine carbonate to achieve superior adhesion and cycle stability compared to conventional single-component binders, while maintaining compatibility with existing manufacturing processes.
Data Source
AI summary
Provided are a composition for a negative electrode, and a negative electrode and lithium battery including the composition. The composition includes a negative active material that contains one or more of a metal or a metalloid, an acrylate-based binder, and a guanidine carbonate.