LiPAI Binder Composition for High-Silicon Li-Ion Anodes
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Solution Overview
Problem
Current lithium ion batteries are limited in storage capacity due to the mechanical stress caused by the swelling and shrinking of silicon particles in the negative electrode, leading to reduced charge cycle stability and battery performance, as existing binders fail to effectively accommodate high silicon loading and require costly high-temperature curing processes.
Innovation Solution
The use of lithiated polyamide-imide (LiPAI) polymers as binders in negative electrodes, which are soluble in water and do not require high-temperature curing, providing improved adhesion to silicon and enhanced cycle stability through an aqueous solution-based processing method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If PAI binder is used to improve silicon adhesion, then excellent adhesion to silicon particles is achieved, but high-temperature curing requirement increases manufacturing cost and complexity
Solution Approach 1:
The invention changes the processing temperature parameter by using a binder system that can be cured at lower temperatures (below 150°C) compared to conventional PAI binders, achieving good silicon adhesion without requiring high-temperature curing processes while still maintaining excellent adhesion performance
2Quantity of substance
If high silicon loading is incorporated into negative electrode to increase storage capacity, then battery capacity is improved, but mechanical stress from swelling and shrinking reduces cycle stability
Solution Approach 1:
The invention provides beforehand cushioning by creating a flexible, adherent binder matrix that anticipates and accommodates the swelling and shrinking of silicon particles during charge cycles, preventing binder failure and maintaining electrode integrity throughout cyclic operation
Solution Approach 2:
The invention changes the mechanical properties of the binder by selecting polymers with appropriate glass transition temperatures and elastic moduli that allow the binder to flexibly accommodate silicon volume changes while maintaining structural integrity over many cycles
Data Source
AI summary
The present invention pertains to a lithiated polyamide-imide (LiPAI) polymer, a method of making the LiPAI, an electrode-forming composition comprising the LiPAI, a method of making a negative electrode with the electrode-forming composition; and a lithium-ion battery comprising the negative electrode.