Silicon Composite Anode Dispersion for Stable Dry Electrode Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrode films in lithium ion batteries face reduced performance due to mechanical properties and volumetric changes during cell cycling, particularly when incorporating silicon materials, leading to non-uniform distribution and aggregation of binders, graphite, and carbon additives.
Innovation Solution
A dry composite material comprising silicon active material, carbon active material, and carbon additive, which are homogeneously dispersed, forming a self-supporting and solvent-free electrode film, fabricated through processes like spray drying to maintain uniform distribution and reduce aggregation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon materials are incorporated into electrode films to increase capacity, then the theoretical capacity increases significantly, but the electrode films suffer from mechanical degradation and non-uniform distribution due to volumetric changes during cycling
Solution Approach 1:
The patent employs composite materials by combining silicon active material particles with carbon additive particles to form a composite electrode film. The carbon matrix provides mechanical stability and structural support, while the silicon particles provide high capacity. This composite structure allows the electrode to withstand volumetric changes during cycling while maintaining electrical conductivity and mechanical integrity, thus resolving the contradiction between high capacity and mechanical stability.
2Manufacturing precision
If conventional wet electrode film processes are used to uniformly distribute binders and carbon additives, then uniform distribution is achieved, but the process requires processing solvents and additional manufacturing complexity
Solution Approach 1:
The patent extracts and eliminates the processing solvent from the conventional wet electrode film process. By using a dry process where carbon additives and silicon active material are mixed without solvent, the method achieves uniform distribution through simple mechanical mixing while avoiding the complexity of solvent handling, drying steps, and associated equipment. This resolves the contradiction by achieving uniform distribution through a simpler, solvent-free process.
Data Source
AI summary
Methods for forming dry composite material for an energy storage device electrode are provided. The method may comprise forming a slurry by mixing a solvent, a silicon active material, a carbon active material, and a carbon additive; and forming the dry composite material comprising the silicon active material, the carbon active material, and the carbon additive by removing the solvent. The carbon additive, silicon active material and carbon active material are substantially homogeneously dispersed in the dry composite material. The dry composite material may be used to form a dry electrode film in dry fabrication processes.