Negative Electrode Slurry Suspending Agent for Low-Impedance Li-Ion Batteries
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Solution Overview
Problem
Lithium ion batteries face issues with the instability of negative electrode slurries, high internal resistance and impedance due to excessive sodium carboxymethyl cellulose (CMC), leading to increased costs and difficulty in improving discharge rates.
Innovation Solution
A preparation method for a suspending agent comprising a mixture of polyvinyl alcohol, polyacrylic acid polymer, xanthan gum, and inorganic powders, along with acidic reagents and cellulose polymers, which replaces CMC, improving slurry stability and reducing internal resistance and impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If sodium carboxymethyl cellulose (CMC) is used as a suspending agent, then the slurry can be prepared, but the slurry stability is poor and carbon materials sediment
Solution Approach 1:
The patent uses a composite suspending agent system comprising polyvinyl alcohol, polyacrylic acid polymer, xanthan gum, and inorganic powder in specific weight ratios. This composite formulation synergistically improves slurry stability and suspending performance, preventing carbon material sedimentation while maintaining uniform distribution, thereby resolving the contradiction between slurry stability and suspending reliability.
2Quantity of substance
If a large amount of CMC is used, then the slurry viscosity increases, but the internal resistance and impedance of the battery increase
Solution Approach 1:
The patent optimizes the composition parameters of the suspending agent system, specifically controlling the weight ratios of polyvinyl alcohol (87-94 parts), polyacrylic acid polymer (0.1-1 part), xanthan gum (5-8 parts), and inorganic powder (0.1-1 part). This parameter optimization achieves effective suspension with minimal total additive quantity, reducing internal resistance and impedance while maintaining necessary viscosity.
3Stability of the object's composition
If a large amount of CMC is used, then the slurry can maintain stability, but the production cost increases
Solution Approach 1:
The patent employs a composite suspending agent system where each component contributes specific functions at optimized concentrations. The synergistic effect of polyvinyl alcohol, polyacrylic acid polymer, xanthan gum, and inorganic powder achieves superior slurry stability with reduced total additive quantity compared to using CMC alone, thereby lowering material costs while maintaining manufacturing feasibility.
4Productivity
If traditional CMC-based slurry is used, then the battery can be assembled, but the discharge rate cannot be improved
Solution Approach 1:
The patent modifies the chemical composition parameters of the suspending agent by replacing CMC with a optimized mixture of polyvinyl alcohol, polyacrylic acid polymer, xanthan gum, and inorganic powder. This parameter change in the slurry formulation improves ion transport properties and electrode interface characteristics, enabling enhanced discharge rate performance while maintaining assembly compatibility.
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 new suspending agent enhances the stability of the negative electrode slurry, reduces internal resistance and impedance, lowers production costs, and improves discharge rates, effectively addressing market feedback and existing battery limitations.
Implementation Method 1
the solubilizing agent is an acidic reagent
Implementation Method 2
adding a solubilizing agent and a pH value regulator... stirring for 1 hour to 2 hours
Implementation Method 3
the negative electrode slurry is insufficient in stability, and the sedimentation of carbon materials such as graphite often occurs
Implementation Method 4
a suspending agent for a negative electrode slurry... enhances the stability of the negative electrode slurry
Implementation Method 5
step 1): sequentially adding a main suspending agent and a synergist in a formula ratio into a vacuum disperser, and starting to stir
Data Source
AI summary
Disclosed are a suspending agent for a negative electrode slurry of a lithium ion battery and a preparation method and application thereof. The suspending agent for the negative electrode slurry comprises the following ingredients in parts by weight: 87 parts to 94 parts of main suspending agent, 0.1 part to 1 part of solubilizing agent, 5 parts to 8 parts of synergist, and 0.1 part to 1 part of pH value regulator. According to the invention, by adding the suspending agent into the negative electrode slurry of the lithium ion battery, a traditional negative electrode suspending agent sodium carboxymethyl cellulose (hereinafter referred to as CMC) material can be replaced, the suspending agent has better suspension stability compared with the CMC material, an amount of the suspending agent is reduced compared with the CMC material.