Thick-Film Negative Electrode Binder for Faster Lithium-Ion Transfer
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Solution Overview
Problem
Existing rechargeable lithium batteries face challenges in achieving high energy density, reduced volume and weight, and improved rapid charging performance, particularly with thick-film negative electrodes that slow down lithium ion movement.
Innovation Solution
A negative electrode design featuring a thick-film active material layer (>40 µm) with a high ionic conductive binder composed of (meth)acrylic acid-based, (C1-C10) alkylene glycol-based, and zwitterionic vinyl- or (meth)acryl-based monomer units, enhancing lithium ion transfer and adhesive strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the negative electrode active material layer thickness is increased to improve energy density, then the energy density increases, but the lithium ion transfer speed decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the binder by incorporating zwitterionic monomer units with specific functional groups that enhance ionic conductivity. This allows the thick electrode structure to maintain fast lithium ion transfer by modifying the binder's physical-chemical properties rather than changing the electrode thickness itself.
Solution Approach 2:
The patent uses a composite binder system combining multiple monomer types (acrylic acid-based, alkylene glycol-based, and zwitterionic vinyl/methacryl-based monomers) to create a material with superior ionic conductivity. This composite approach enables the thick electrode to achieve both high energy density and rapid charging by integrating multiple functional properties in the binder material.
2Quantity of substance
If a thick-film negative electrode is used to increase energy density, then the energy density increases, but the rapid charging performance deteriorates
Solution Approach 1:
The patent modifies the binder's ionic conductivity parameter by introducing zwitterionic monomer units with specific functional groups. This parameter change enables rapid lithium ion diffusion throughout the thick electrode during fast charging, resolving the contradiction between energy density and charging speed.
Solution Approach 2:
The patent enhances the local quality of the binder material at the molecular level by incorporating zwitterionic structures that create favorable local environments for lithium ion transport. This localized improvement in ionic conductivity within the thick electrode structure enables rapid charging performance despite the increased thickness.
3Speed
If the binder ionic conductivity is increased to improve lithium ion transfer, then the rapid charging performance improves, but the adhesive strength may be compromised
Solution Approach 1:
The patent creates a composite binder combining multiple monomer types where zwitterionic units provide ionic conductivity and acrylic acid/alkylene glycol units provide adhesive properties. This composite structure allows simultaneous achievement of high lithium ion transfer speed and strong adhesive strength through synergistic material design.
Solution Approach 2:
The patent designs a multi-functional binder that simultaneously performs multiple roles: zwitterionic monomer units enhance ionic conductivity for fast charging, while acrylic acid and alkylene glycol units provide adhesive strength for electrode integrity. This multi-functionality resolves the contradiction between ion transfer speed and adhesive strength.
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 design increases energy density, reduces battery volume and weight, and improves rapid charging performance by optimizing lithium ion movement and adhesive strength.
Implementation Method 1
a high ionic conductive binder... enhancing lithium ion transfer
Implementation Method 2
an active material capable of intercalating and deintercalating lithium ions
Implementation Method 3
electrical energy is produced through oxidation and reduction reactions when lithium ions are intercalated and deintercalated
Data Source
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AI summary
The present invention relates to a negative electrode, wherein the electrode includes a current collector, and a negative electrode active material layer located on the current collector and including a negative electrode active material and a high ionic conductive binder. The high ionic conductive binder includes a first structural unit derived from a (meth)acrylic acid-based monomer, a second structural unit derived from a (C1-C10) alkylene glycol-based monomer, and a third structural unit derived from a zwitterionic vinyl-based monomer or a zwitterionic (meth)acryl-based monomer. A thickness of the negative electrode active material layer is greater than or equal to about 40 µm. The negative electrode can increase the energy density of a rechargeable lithium battery, while reducing the volume and weight of the rechargeable lithium battery and contributing to improving rapid charging performance.