Battery Electrode Network Using Water-Soluble Binder for Stable Adhesion
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Solution Overview
Problem
Conventional lithium ion batteries face challenges with binders that require environmentally unfriendly or toxic solvents for processing, and these binders may not provide sufficient mechanical compatibility with electrode active materials to withstand expansion and contraction during charging and discharging.
Innovation Solution
The development of an electrode with a polymeric additive that is soluble in water or alcohol, which promotes a safe and clean manufacturing process, and is integrated into a network of high aspect ratio carbon elements with electrode active material particles, enhancing mechanical stability and electrical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional binders are used to provide good mechanical properties, then mechanical stability is improved, but environmental friendliness deteriorates due to requirement of toxic solvents
Solution Approach 1:
The patent changes the solvent parameter from toxic organic solvents to water or alcohol, and modifies the binder chemistry to use polyacrylic acid or carboxymethyl cellulose that are compatible with these environmentally friendly solvents while maintaining mechanical stability
Solution Approach 2:
The patent uses water-soluble or alcohol-soluble polymers that can be processed with simple, inexpensive, and environmentally benign solvents, eliminating the need for costly and toxic solvent recovery systems
2Strength
If conventional binders are used to maintain film contact with current collector, then adhesion is improved, but mechanical compatibility with electrode active material deteriorates due to inability to withstand expansion and contraction
Solution Approach 1:
The patent creates a composite binder system combining polyacrylic acid or carboxymethyl cellulose with conductive carbon materials and metal oxides, which provides both strong adhesion to the current collector and mechanical flexibility to accommodate electrode active material expansion and contraction during charging and discharging cycles
Solution Approach 2:
The patent applies different functional components within the binder layer at different locations - adhesive components near the current collector for strong bonding, and flexible polymer components throughout the layer to accommodate volume changes of the electrode active material particles
3Power
If electrode film is coated on current collector to contain active material, then electrical performance is improved, but contact stability deteriorates when film does not maintain sufficient contact
Solution Approach 1:
The patent applies a binder layer to the current collector surface before coating the electrode active material, creating a pre-formed adhesive base that ensures stable contact and prevents delamination during subsequent battery assembly and operation
Data Source
AI summary
Disclosed herein is an energy storage device that comprises a cathode and an anode, wherein at least one of the anode and cathode includes an active layer comprising a network of high aspect ratio carbon elements defining void spaces within the network; and a plurality of electrode active material particles disposed in the void spaces within the network; and the network of high aspect ratio carbon elements has an intersection density of at least 0.1 per μm2.