Battery Electrode Slurry Mixing for Faster Homogeneous Fabrication
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Solution Overview
Problem
Current methods for fabricating battery electrodes, such as the pressed powder process, are inefficient and result in inhomogeneous mixing and low mechanical integrity due to the use of ball mills or low to medium speed overhead mixers, which take a long time to achieve the necessary granulation and often produce undesirably low-quality active media.
Innovation Solution
A method involving the preparation of a slurry with a solid content less than 80 wt% in solvents, mixed at a high shear rate exceeding 94,200/minute to form a homogenous active medium, which is then separated from the solvents, significantly reducing mixing time and improving the efficiency of the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ball mill or low to medium speed overhead mixer is used for powder mixing, then the mixing process can be performed with simple equipment, but the mixing time exceeds one day and the mechanical integrity is undesirably low
Solution Approach 1:
The patent changes the physical state parameter of the mixture from dry powder to slurry form (adding liquid binder), and changes the mixing mechanism parameter from low-speed mechanical mixing to high-speed dispersion mixing. This transforms the mixing process from a time-consuming mechanical operation to a rapid dispersion process, reducing mixing time from over one day to significantly shorter duration while improving homogeneity and mechanical integrity.
2Device complexity
If ball mill or low to medium speed overhead mixer is used for powder mixing, then the equipment complexity remains low, but the homogeneity of powder mixing is inhomogeneous
Solution Approach 1:
The patent changes the physical state parameter from dry powder to slurry, enabling the use of high-speed mixing equipment that provides superior homogeneity. The liquid binder acts as a medium that facilitates uniform distribution of active material particles, achieving homogeneous mixing that dry powder processes cannot accomplish, even with complex equipment.
3Ease of manufacture
If pressed powder process is used for electrode fabrication, then the manufacturing cost is cost effective, but the mechanical integrity is undesirably low
Solution Approach 1:
The patent changes the binding mechanism from mechanical pressing of dry powders to chemical bonding through liquid binder infiltration. The slurry formulation with appropriate binder content and viscosity enables the binder to penetrate and bond particles together, creating stronger mechanical integrity that cannot be achieved by pressing alone, while maintaining cost-effectiveness through the simplicity of the slurry casting process.
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 allows for the rapid and efficient production of high-quality battery electrodes, reducing the time from powdered ingredients to active medium from several days to less than 10 hours, with improved mechanical integrity and homogeneity.
Implementation Method 1
The slurry is mixed so as to apply a shear rate higher than 94200/minute to the slurry and form a mixed slurry
Data Source
AI summary
Preparing a battery electrode includes preparing a slurry having a solid content less than 80 wt %. The slurry includes ingredients in one or more solvents. The ingredients are components of an active medium of the battery electrode. The slurry is mixed so as to apply a shear rate higher than 94200/minute to the slurry and form a mixed slurry. The ingredients are separated from the one or more solvents in the mixed slurry. The ingredients are applied to a current collector after the ingredients are separated from the one or more solvents in the mixed slurry.