Positive electrode for rechargeable lithium battery and rechargeable lithium battery including the same
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Solution Overview
Problem
Rechargeable lithium batteries face challenges in increasing cycle-life while reducing electrical resistance and enhancing adhesion of the positive electrode, as polyvinylidene fluoride-based binders limit performance.
Innovation Solution
The use of a hydrogenated nitrile butadiene rubber (HNBR) derivative as a binder in the positive electrode mixture layer, either in reduced amounts or as a complete replacement for polyvinylidene fluoride-based binders, to improve adhesion and lower electrical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyvinylidene fluoride-based binders are used in the positive electrode mixture layer, then adhesion is improved, but electrical resistance increases and cycle-life is limited
Solution Approach 1:
The patent changes the chemical composition parameter of the binder from polyvinylidene fluoride-based to carboxymethyl cellulose-based, which fundamentally alters the electrical and mechanical properties of the positive electrode mixture layer, thereby reducing electrical resistance while maintaining adhesion and improving cycle-life
Solution Approach 2:
The patent uses a composite binder system comprising carboxymethyl cellulose and at least one of polyvinylidene fluoride or its derivatives, combining the adhesive properties of carboxymethyl cellulose with the conductive properties of polyvinylidene fluoride or its derivatives to achieve both good adhesion and low electrical resistance
2Strength
If polyvinylidene fluoride-based binders are used in the positive electrode mixture layer, then adhesion is improved, but electrical resistance increases
Solution Approach 1:
The patent changes the chemical composition parameter of the binder from polyvinylidene fluoride-based to carboxymethyl cellulose-based, which fundamentally alters the electrical and mechanical properties of the positive electrode mixture layer, thereby reducing electrical resistance while maintaining adhesion and improving cycle-life
Solution Approach 2:
The patent uses a composite binder system comprising carboxymethyl cellulose and at least one of polyvinylidene fluoride or its derivatives, combining the adhesive properties of carboxymethyl cellulose with the conductive properties of polyvinylidene fluoride or its derivatives to achieve both good adhesion and low electrical resistance
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
This approach enhances the cycle-life of rechargeable lithium batteries by increasing adhesion strength and reducing electrical resistance, thereby improving overall battery performance.
Implementation Method 1
the first binder includes a hydrogenated nitrile butadiene rubber (HNBR) derivative... increasing the adhesion of the positive electrode and lowering the resistance
Data Source
AI summary
Disclosed are a positive electrode for a rechargeable lithium battery and a rechargeable lithium battery including the same. The positive electrode includes a positive electrode current collector and a positive electrode mixture layer on the positive electrode current collector, wherein the positive electrode mixture layer includes a positive electrode active material and a first binder, and the first binder is a hydrogenated nitrile butadiene rubber (HNBR) derivative.