Plasticized PVDF Binder for Battery Electrodes With Glyme Additives
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Solution Overview
Problem
Current PVDF binders in electrode fabrication for batteries face challenges in enhancing conductivity and ion diffusion, leading to impaired rate performance and cyclability, and existing plasticizers do not effectively address these issues.
Innovation Solution
An electrode slurry comprising 60 wt.% to 98 wt.% electrode active material, 0 wt.% to 20 wt.% conductive carbon, and 1 wt.% to 20 wt.% of a plasticized binder, where the plasticized binder includes polyvinylidene fluoride (PVDF) and a plasticizer such as tetraglyme, diglyme, or triglyme, is used, improving connectivity and electrochemical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional PVDF binder is used in electrode fabrication, then the electrode structure is maintained and adhesion is provided, but the conductivity and ion diffusion are insufficient, leading to impaired rate performance and cyclability
Solution Approach 1:
The patent applies parameter changes by modifying the physical and chemical properties of PVDF binder through plasticization. Specifically, it changes the glass transition temperature (Tg) and molecular chain mobility of PVDF by incorporating plasticizers, which transforms the binder from a rigid state to a more flexible state with enhanced ionic conductivity and ion diffusion capability, thereby improving rate performance and cyclability without compromising structural integrity
Solution Approach 2:
The patent employs composite materials by creating a plasticized PVDF binder system that combines PVDF polymer with plasticizing agents. This composite approach integrates the structural stability of PVDF with the conductivity-enhancing properties of plasticizers, resulting in a binder composite that simultaneously provides mechanical support and enhanced ionic transport pathways for improved electrode performance
2Stability of the object's composition
If existing plasticizers are used with PVDF binder, then some improvement in flexibility is achieved, but the electrochemical performance (conductivity and ion diffusion) is not effectively enhanced
Solution Approach 1:
The patent applies parameter changes by selecting and optimizing specific plasticizing agents that simultaneously address flexibility and electrochemical performance. It modifies the chemical composition parameters of the plasticizer-PVDF system to achieve optimal glass transition temperature reduction while maximizing ionic conductivity enhancement, thereby resolving the contradiction between mechanical flexibility and electrochemical performance
Solution Approach 2:
The patent uses plasticizers as intermediary substances that mediate between the PVDF polymer chains and the electrolyte environment. These intermediaries facilitate ion transport by creating pathways between PVDF chains while maintaining the structural framework, thus simultaneously improving flexibility and electrochemical performance through their dual functional role
Data Source
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AI summary
The presently claimed invention relates to a plasticizer for polyvinylidene fluoride (PVDF), which is used as a binder for electrode fabrication.