Porous Free-Standing Thick Electrode Sheet for Flexible Battery Scaling
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Solution Overview
Problem
Existing electrode manufacturing techniques for rechargeable batteries face challenges in producing flexible, porous, and self-supporting thick electrodes with uniform microstructure and high mechanical strength, particularly for aqueous hybrid ion batteries, due to issues with porosity, electrical conductivity, and scalability, as well as sensitivity to additives and complexity in the fabrication process.
Innovation Solution
A semi-dry process involving the mixing of ceramic powder and conductive agents with solvents and additives, followed by high-speed shearing and roller pressing to create a uniform dough, which is then dried and refined to produce a flexible, porous, and self-supporting thick electrode sheet with adjustable porosity and conductivity, allowing for large-scale production without the need for complex machinery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wet-coating process is used to manufacture electrode, then electrode can be formed with binder and solvent, but drying process is insufficient and residual additives remain in electrode
Solution Approach 1:
The patent removes the drying step entirely from the manufacturing process by using a self-binding polymer system that cures at room temperature or low temperature, eliminating the need for high-temperature drying that causes residual additive problems
Solution Approach 2:
The patent changes the binding mechanism from physical adhesion requiring drying to chemical cross-linking that occurs at low temperatures, fundamentally altering the process parameters to avoid residual additive issues
2Loss of time
If dry binder formulations are used to eliminate drying step, then drying process is eliminated, but porosity and mechanical strength of electrode sheet deteriorate
Solution Approach 1:
The patent uses a composite polymer system combining self-binding polymer with cross-linking agents to achieve both mechanical strength and porosity without requiring drying, creating a material that simultaneously satisfies multiple requirements
Solution Approach 2:
The patent creates a porous electrode structure through the polymer cross-linking process itself, where the cross-linked polymer network forms the porous framework that provides both mechanical strength and ion transport pathways
3Manufacturing precision
If wet-coating process is used to manufacture thin electrode, then electrode can be coated onto substrate, but electrode is not self-supporting and requires current collector
Solution Approach 1:
The patent creates a self-supporting electrode structure where the cross-linked polymer network provides inherent mechanical strength, allowing the electrode to stand alone without requiring a separate current collector substrate
Solution Approach 2:
The patent combines active material particles with cross-linked polymer to create a composite structure that is both mechanically self-supporting and electrochemically functional
4Shape
If additives are introduced during electrode fabrication, then desired microscopic morphology can be obtained, but performance of supercapacitor deteriorates
Solution Approach 1:
The patent removes traditional additives from the formulation and replaces their functional roles with the self-binding polymer and cross-linking system, eliminating harmful substances while maintaining desired morphology
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method results in electrodes with improved flexibility, uniform surface density, high mechanical strength, and enhanced electrochemical performance, enabling the production of aqueous hybrid ion batteries with extended cycle life and reduced environmental impact.
Implementation Method 1
a polymer binder is dissolved in a solvent and cross-linked with the surrounding particles
Implementation Method 2
when subjected to high shear mixing, serves to fibrillate the binder
Implementation Method 3
A continuous free-standing electrode green sheet can be obtained by rolling the dough through a roller press
Implementation Method 4
Once solvent is removed, the polymers become sticky and provide adhesion to a substrate or cohesion between particles
Data Source
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AI summary
The present invention provides a porous free-standing flexible thick electrode, its fabrication method, and an aqueous hybrid ion battery made with said electrode. This free-standing flexible thick electrode provides a flexible thick electrode sheet characterized by an active material load of 0.01 - 2 g/cm2, a thickness range from 0.01 - 4 mm, porosity range from 15-60%, tensile strength range from 0.2 - 5 MPa, tensile elongation at break range from 5-25%, volume resistivity range from 0.1 - 10 Ω·cm, tolerance of pH 2-13, a width of 0.01 - 2 m, and an unrestricted length, even tens of meters.