Electrode Paste Production Using Micromixing Shear Energy
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Solution Overview
Problem
Existing methods for producing electrode pastes struggle to achieve high solid content concentrations above 65% by mass without increasing viscosity to problematic levels, making application challenging.
Innovation Solution
A micromixing treatment step using a micromixer with shear energy between 4,000 kJ/L and 16,000 kJ/L is employed to knead a mixture of active materials and solvents, allowing for the production of low-viscosity electrode pastes with high solid content concentrations, along with the addition and uniform dispersion of additives like lithium phosphate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the solid content concentration of the electrode paste is increased to exceed 65% by mass, then the drying time and solvent volume are reduced, but the viscosity of the electrode paste becomes too high making application problematic
Solution Approach 1:
The patent changes the physical-chemical parameters of the mixture by controlling the particle size distribution of the active material (D10: 1-5 μm, D50: 5-15 μm, D90: 15-30 μm) and using a specific binder (polyacrylonitrile with specific molecular weight and acrylonitrile content). These parameter changes enable the paste to maintain low viscosity even at high solid content concentrations (65-75 wt%), resolving the contradiction between productivity and ease of operation
Solution Approach 2:
The patent uses a composite material system consisting of active material particles with specific size distribution, a specific binder (polyacrylonitrile), and a solvent (NMP). This composite formulation creates a paste with optimized rheological properties that allows high solid content (65-75 wt%) while maintaining applicability, thus resolving the contradiction between reduced drying time and ease of application
2Loss of substance
If the solid content concentration of the electrode paste is increased to exceed 65% by mass, then the solvent volume is reduced, but the viscosity of the electrode paste becomes too high making application problematic
Solution Approach 1:
The patent changes the particle size distribution parameters (D10: 1-5 μm, D50: 5-15 μm, D90: 15-30 μm) and binder characteristics to optimize paste flow properties. This enables reducing solvent volume while maintaining low viscosity and good applicability at high solid content concentrations (65-75 wt%), resolving the contradiction between loss of substance and ease of operation
Solution Approach 2:
The patent employs a composite material system with specifically sized active material particles, polyacrylonitrile binder, and NMP solvent. This composite formulation reduces the required solvent volume while maintaining paste applicability through optimized interfacial interactions and rheological properties, resolving the contradiction between solvent reduction and ease of application
3Device complexity
If conventional mixing methods are used for high solid content mixtures, then the mixing process is simpler, but the viscosity becomes too high and dispersion is insufficient
Solution Approach 1:
The patent performs preliminary classification of the active material into specific particle size ranges (D10: 1-5 μm, D50: 5-15 μm, D90: 15-30 μm) before mixing. This preliminary action ensures that the subsequent mixing process, even with simple equipment, achieves excellent dispersion uniformity and low viscosity at high solid content concentrations, resolving the contradiction between device complexity and manufacturing precision
Solution Approach 2:
The patent changes the particle size distribution parameters of the active material and selects specific binder characteristics (polyacrylonitrile with specific molecular weight and acrylonitrile content). These parameter changes enable achieving uniform dispersion with simple mixing equipment, resolving the contradiction between mixing process complexity and dispersion uniformity
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 method enables the production of electrode pastes with high solid content concentrations that are easily applicable, while maintaining low viscosity and improving battery performance by uniformly distributing additives, thereby suppressing electrolyte decomposition and enhancing capacity retention and output.
Implementation Method 1
the shear energy in the mixing section of the micromixer is preferably within a range from not less than 4,000 kJ/L to not more than 16,000 kJ/L
Data Source
AI summary
Provided is an electrode paste production method that can produce a low-viscosity electrode paste which can be readily applied even if the solid content concentration is high, for example in excess of 65% by mass. The electrode paste production method, in which the paste contains an active material and a solvent, includes a micromixing treatment step in which a mixture of a solid fraction containing an active material blended at a high solid content concentration and a solvent is kneaded using a micromixer.