Dry Electrode Powder Crushing for Uniform Free-Standing Films
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Solution Overview
Problem
Conventional dry electrode manufacturing methods for rechargeable batteries result in non-uniform thickness and width of the free-standing film due to uneven fiberized binder lengths and particle size distributions in the dry powder.
Innovation Solution
A manufacturing method that involves fiberizing a mixture of active material, conductive material, and binder, followed by first and second crushing to form a minute powder with a controlled particle size distribution, and then calendering this powder into a free-standing film with uniform thickness and width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fiberized dry powder is directly calendered without crushing, then the manufacturing process is simpler and faster, but the free-standing film has non-uniform thickness and width
Solution Approach 1:
The patent applies preliminary action by performing first crushing and second crushing of the fiberized dry powder before calendering. This pre-processing step creates a minute powder with controlled particle size distribution (94-99 wt% in 45-1000 μm range), which then enables uniform calendering into free-standing films with consistent thickness and width, resolving the contradiction between manufacturing efficiency and film uniformity
2Ease of manufacture
If the fiberized binder length is not controlled, then the mixing and fiberization process is simpler, but the particle size distribution is uneven leading to non-uniform film properties
Solution Approach 1:
The patent applies segmentation by dividing the fiberized dry powder into smaller particles through first crushing and second crushing operations. This segmentation process transforms the fiberized structure into minute powder with controlled particle size distribution (94-99 wt% in 45-1000 μm range), achieving uniform particle size while maintaining process simplicity through staged crushing operations
Solution Approach 2:
The patent applies parameter changes by controlling the particle size distribution through specific crushing parameters. The first crushing and second crushing operations use optimized parameters to achieve a particle size distribution where 94-99 wt% of particles fall within 45-1000 μm, directly improving the uniformity of the resulting free-standing film
Data Source
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AI summary
A manufacturing method of a dry electrode includes fiberizing a mixture including an active material, a conductive material, and a binder into a fiberized dry powder; first crushing and second crushing the dry powder into a minute powder; and calendering the minute powder into a free-standing film.