Aqueous Cellulose Binder for Lithium Battery Electrodes
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Solution Overview
Problem
Conventional lithium rechargeable batteries face challenges in achieving optimal dispersion properties and adherence of active materials in electrodes, leading to increased resistance and reduced power performance.
Innovation Solution
An aqueous active material composition is developed, comprising a combination of cellulose compounds with specific degrees of substitution, along with a binder and conductive materials, to enhance dispersion and adsorption strength, thereby improving electrode performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single type of cellulose binder is used in the electrode slurry, then the manufacturing process is simple, but the dispersion properties and adherence of active materials are insufficient leading to increased resistance
Solution Approach 1:
The patent applies composite materials by combining two different cellulose compounds (first cellulose compound and second cellulose compound) with distinct degrees of substitution to form a composite binder system. This composite approach leverages the complementary properties of each cellulose type to achieve superior dispersion and adherence of active materials compared to using a single cellulose binder, thereby resolving the contradiction between improved reliability and increased complexity.
Solution Approach 2:
The patent utilizes parameter changes by varying the degree of substitution of cellulose compounds to optimize performance. The first cellulose compound has a degree of substitution of about 0.5 to about 0.9, while the second cellulose compound has a degree of substitution of about 1.1 to about 1.5. By controlling and adjusting this critical parameter, the patent achieves optimal balance between water solubility, dispersion properties, and adherence, resolving the contradiction without requiring complex multi-component systems.
2Productivity
If water is used as a solvent with a single cellulose binder, then the manufacturing is simple and cost-effective, but the dispersion properties of active material are poor resulting in increased resistance
Solution Approach 1:
The patent employs composite materials by formulating a slurry that contains both first and second cellulose compounds with different degrees of substitution. This composite binder system in aqueous solution provides enhanced dispersion properties for active materials compared to single-cellulose systems, thereby improving power performance while maintaining the simplicity of water-based processing and manufacturing.
3Power
If conventional single-cellulose binders are used, then the manufacturing process is straightforward, but the electrode exhibits higher resistance and reduced power performance
Solution Approach 1:
The patent resolves the contradiction between improved power performance and increased formulation complexity by using a composite of two cellulose compounds. The synergistic interaction between the first cellulose compound (degree of substitution 0.5-0.9) and the second cellulose compound (degree of substitution 1.1-1.5) enhances active material dispersion and reduces electrode resistance, delivering superior power performance while keeping the formulation relatively simple and manufacturable.
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 composition achieves reduced resistance and improved adherence, resulting in enhanced power performance of rechargeable lithium batteries by ensuring effective dispersion and adsorption of active materials.
Implementation Method 1
a water-soluble cellulose mixture, wherein the water-soluble cellulose mixture includes a first cellulose compound having a degree of substitution of about 0.5 to about 0.9, and a second cellulose compound having a degree of substitution of about 1.1 to about 1.5
Data Source
AI summary
An aqueous active material composition, an electrode, and a rechargeable lithium battery including the same, the aqueous active material composition including an active material; a binder; and a water-soluble cellulose mixture, wherein the water-soluble cellulose mixture includes a first cellulose compound having a degree of substitution of about 0.5 to about 0.9 and a second cellulose compound having a degree of substitution of about 1.1 to about 1.5.