Comb-Shaped Cathode Dispersant for Low-Resistance Electrode Coating
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Solution Overview
Problem
Existing lithium-ion battery electrode plates face issues with poor dispersion effects and high internal resistance, leading to cracking, powder falling, and uneven coating, which negatively impact energy density and production efficiency.
Innovation Solution
A preparation method for a comb-shaped positive electrode dispersing material using a solvent, unsaturated cyclic monomer, unsaturated branched polyether, and (meth)acrylate monomer, combined with an initiating agent and phosphoric acid, to create a comb-shaped positive dispersing material, which is then mixed with lithium iron phosphate and conductive carbon black for low-internal-resistance electrode plate production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a positive electrode dispersing material is introduced to improve dispersion effect, then coating uniformity is improved, but internal resistance of the electrode plate increases
Solution Approach 1:
The patent changes the chemical structure parameters of the dispersing material by introducing comb-shaped architecture with specific side chains containing oxygen-containing functional groups. This structural parameter change enables the material to provide both good dispersion (improving coating uniformity) and low internal resistance through enhanced conductivity and interfacial compatibility
Solution Approach 2:
The dispersing material is designed as a composite structure combining main chain segments with grafted side chains. The main chain provides structural backbone while the side chains with oxygen-containing groups (such as carboxyl, hydroxyl, or ether groups) provide dispersing and conductive functions, achieving both good coating uniformity and low internal resistance through synergistic composite structure
2Loss of substance
If solid content of slurry is increased to reduce NMP solvent use, then environmental protection and cost are improved, but slurry dispersion and coating difficulty increase
Solution Approach 1:
The comb-shaped dispersing material acts as an intermediary substance between the positive electrode material particles and the slurry matrix. Its multifunctional structure with polar groups and flexible side chains enables it to mediate interactions, providing steric hindrance and electrostatic repulsion to prevent aggregation even at high solid contents, thus maintaining good dispersion without requiring large amounts of NMP solvent
Solution Approach 2:
The patent changes the molecular weight and side chain structure parameters of the dispersing material to optimize its performance at high solid contents. By adjusting these parameters, the dispersing material can provide adequate steric hindrance and solvation effects even when solvent content is reduced, enabling both environmental protection (less NMP) and ease of manufacture (good dispersion)
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 method results in a dispersing material with improved dispersion and reduced viscosity, enabling high-speed coating with a smooth and crack-free electrode plate, significantly lowering internal resistance and enhancing battery energy density.
Implementation Method 1
mixing a solvent, an unsaturated cyclic monomer, unsaturated branched polyether and a (methyl) acrylate monomer to obtain a mixed solution... heating the mixed solution to a reaction temperature, adding an initiating agent, and keeping the reaction temperature for reaction
Implementation Method 2
adding phosphoric acid which is equal to the (methyl) acrylate monomer in mole into the semi-finished product for esterification and high-temperature dehydration to obtain the comb-shaped positive dispersing material
Implementation Method 3
the introduction of a positive electrode dispersing material can effectively solve the above problems... the comb-shaped positive electrode dispersing material prepared by the method of the present invention can increase a solid content of a lithium iron phosphate positive electrode slurry to 60wt%, so that a viscosity of the material is greatly reduced
Data Source
Figure 1
AI summary
The invention belongs to the technical field of battery dispersing materials, and discloses a preparation method of a comb-shaped positive electrode dispersing material, which comprises the following steps of: mixing a solvent, an unsaturated cyclic monomer, unsaturated branched polyether and a (methyl) acrylate monomer to obtain a mixed solution; heating the mixed solution to a reaction temperature, adding an initiating agent, and keeping the reaction temperature for reaction to obtain a semi-finished product; and adding phosphoric acid which is equal to the (methyl) acrylate monomer in mole into the semi-finished product for esterification and high-temperature dehydration to obtain the comb-shaped positive dispersing material. The invention further discloses a preparation method of a low-internal-resistance electrode plate by taking the comb-shaped positive electrode dispersion material as a raw material. The above method is simple in synthesis step and easy to operate, and a dispersion effect is obviously better than that of an existing dispersing material; coating efficiency can be improved, and the coated electrode plate is flat and smooth in surface and free of cracking and powder falling; and compared with a contrast sample, an internal resistance of the electrode plate is obviously reduced, and an overall energy density of a battery is improved.