Lithium Battery Electrode Plate With Crosslinked Polyimide Binder
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Solution Overview
Problem
Existing rechargeable lithium batteries face challenges in achieving high adhesive strength between active materials and current collectors while minimizing the use of fluorine-containing binders to comply with environmental regulations, which affects battery resistance and lifespan.
Innovation Solution
The use of a polyimide-based binder crosslinked with diamine, amino alcohol, or dialcohol compounds to form an active material layer on the current collector, increasing adhesive strength and active material content without fluorine, thereby reducing resistance and improving battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If PVDF binders are used to provide strong adhesive strength, then adhesive strength is improved, but environmental compliance deteriorates due to fluorine content
Solution Approach 1:
The invention changes the chemical composition parameters by replacing fluorine-containing PVDF binders with fluorine-free alternatives such as carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR), achieving both environmental compliance and adequate adhesive strength without fluorine
Solution Approach 2:
The invention uses composite binder systems combining multiple fluorine-free materials (CMC, SBR, and conductive additives) to achieve the adhesive performance previously provided by PVDF, while eliminating harmful fluorine content
2Quantity of substance
If binder content is reduced to increase active material amount, then energy density is improved, but adhesive strength deteriorates
Solution Approach 1:
The invention optimizes the binder content parameter to minimal effective levels (0.1-5 wt%) while using highly efficient fluorine-free binder systems that maintain strong adhesion at lower concentrations, allowing maximum active material loading
Solution Approach 2:
The invention replicates the high adhesive performance characteristic of PVDF binders using fluorine-free alternatives, achieving the same functional effect (strong adhesion at low concentrations) without the harmful fluorine content
3Loss of energy
If binder content is reduced to improve energy density, then resistance is reduced, but adhesive strength deteriorates
Solution Approach 1:
The invention changes the binder composition parameters to use fluorine-free materials with optimized molecular structures that provide high adhesive efficiency at minimal concentrations, reducing overall binder content to 0.1-5 wt% and thereby reducing resistance while maintaining adhesion
Solution Approach 2:
The invention employs composite binder formulations combining CMC, SBR, and conductive additives in optimized ratios that maximize adhesive performance per unit mass, enabling ultra-low binder content that simultaneously reduces resistance and maintains strong adhesion
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 crosslinked polyimide-based binder system enhances adhesive strength, allowing for higher active and conductive material content, thus reducing battery resistance and improving rate capability and lifespan while being environmentally friendly.
Implementation Method 1
a crosslinked product of a binder and a crosslinking agent, the binder includes a polyimide based binder, and the crosslinking agent includes at least one of a diamine based compound, an amino alcohol based compound, or a dialcohol based compound
Data Source
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AI summary
An electrode plate for rechargeable lithium batteries and a rechargeable lithium battery including the same are disclosed. The electrode plate for rechargeable lithium batteries includes a current collector and an active material layer on the current collector, wherein the active material layer includes an active material; and a crosslinked product of a binder and a crosslinking agent. The binder includes a polyimide based binder, and the crosslinking agent includes at least one of a diamine based compound, an amino alcohol based compound, and a dialcohol based compound.