Low-Specific-Gravity PTFE Binder Powder for Low-Gas Electrodes
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Solution Overview
Problem
Secondary batteries, such as lithium-ion batteries, face challenges in achieving higher energy densities and maintaining battery characteristics, including gas generation and electrode deterioration, especially during high-temperature storage.
Innovation Solution
A polytetrafluoroethylene (PTFE) powder with a standard specific gravity of 2.200 or less is used as an electrode binder, which is substantially free from water, allowing for improved electrode strength and reduced gas generation, and can be mixed with active materials without organic solvents, enhancing the production process and binding force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional aqueous dispersion of polytetrafluoroethylene is used as a binder, then the electrode can be formed, but gas generation and electrode deterioration occur during high-temperature storage
Solution Approach 1:
The patent changes the physical and chemical parameters of the PTFE binder by controlling its standard specific gravity to 2.200 or less and ensuring it is substantially free from water. This parameter change transforms the binder from a conventional aqueous dispersion that generates gas into a low-specific-gravity, water-free powder that eliminates gas generation while maintaining electrode strength and binding performance.
2Strength
If conventional PTFE binder with higher specific gravity is used, then the binding force is sufficient, but the electrode strength and binding force are insufficient
Solution Approach 1:
The patent identifies standard specific gravity as a critical parameter and sets it to 2.200 or less. This specific gravity threshold creates an optimal balance where the PTFE powder provides sufficient binding force and electrode strength while maintaining the desired low-density characteristic that prevents gas generation and improves overall electrode performance.
3Ease of manufacture
If organic solvents are used to mix PTFE with active materials, then the mixing process is effective, but production costs increase and environmental concerns arise
Solution Approach 1:
The patent extracts and eliminates organic solvents from the mixing process by using PTFE powder that is substantially free from water and other solvents. This allows direct mixing of PTFE with active materials without requiring organic solvent mediators, thereby reducing production costs, eliminating environmental concerns associated with solvent disposal, and simplifying the manufacturing process while maintaining effective mixing and binding.
Data Source
AI summary
The disclosure aims to provide a polytetrafluoroethylene powder for an electrode binder which can not only reduce or prevent gas generation inside a battery cell and deterioration of battery characteristics but also improve the electrode strength, an electrode binder, an electrode mixture, an electrode, and a secondary battery. Provided is a polytetrafluoroethylene powder for use as an electrode binder, the polytetrafluoroethylene having a standard specific gravity of 2.200 or less and being substantially free from water.