Staged Roller Pressing for High-Density Battery Electrodes
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Solution Overview
Problem
Existing battery electrode manufacturing methods face challenges in forming high-density active material layers due to uneven compression, which can lead to decreased electronic conductivity.
Innovation Solution
A battery electrode manufacturing device comprising a powder supply unit, a conveyance unit, a preliminary press unit with multiple pairs of small diameter rollers, and a press unit with larger diameter rollers, which compresses the wet powder in stages to form a high-density active material layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a large-diameter roller is used for the first compression, then the compression force is sufficient, but the electrode composition cannot be compressed in a flat state and becomes uneven
Solution Approach 1:
The compression process is divided into two distinct stages: a first compression stage using a large-diameter roller to apply sufficient compression force, and a second compression stage using a small-diameter roller to achieve flat and uniform compression. This segmentation allows each roller to perform its optimal function without compromise.
Solution Approach 2:
The first compression using the large-diameter roller is performed as a preliminary action to provide initial compression force and density to the electrode composition. This preliminary compression prepares the material for the subsequent second compression stage, where the small-diameter roller achieves the final flat and uniform compression.
2Productivity
If a large-diameter roller is used for the first compression, then the compression capacity is high, but the electronic conductivity decreases due to uneven compression
Solution Approach 1:
The compression process is segmented into two stages with different roller sizes: the first stage uses a large-diameter roller for high compression capacity and productivity, while the second stage uses a small-diameter roller to ensure uniform compression that maintains electronic conductivity. This segmentation resolves the conflict between productivity and reliability.
Solution Approach 2:
The first compression by the large-diameter roller serves as a preliminary action that achieves high compression capacity and productivity. The subsequent second compression by the small-diameter roller then ensures the reliability aspect of electronic conductivity is maintained through uniform compression.
3Manufacturing precision
If a small-diameter roller is used for compression, then the flatness is improved, but the compression force is insufficient for high-density formation
Solution Approach 1:
The compression process is segmented so that the small-diameter roller is used in the second compression stage specifically to achieve flatness and uniform compression. The large-diameter roller handles the first compression stage to provide sufficient compression force. This segmentation allows each roller type to excel at its designated function.
4Manufacturing precision
If multiple compression stages are implemented, then the active material layer density is improved, but the device complexity increases
Solution Approach 1:
The compression system is segmented into two straightforward stages using rollers of different diameters, where the first stage uses a large-diameter roller and the second stage uses a small-diameter roller. This simple segmentation achieves high density without excessive device complexity.
Solution Approach 2:
The key parameter that changes between stages is the roller diameter. The first compression uses a large-diameter roller, and the second compression uses a small-diameter roller. This single parameter change (roller diameter) enables the multi-stage compression process to achieve high density while keeping the device complexity manageable.
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 effectively forms high-density active material layers, improving electronic conductivity and preventing uneven compression issues.
Implementation Method 1
a preliminary press unit, that includes a pair of preliminary rollers, and that compresses the wet powder supplied from the powder supply unit to the base film
Implementation Method 2
a press unit having a pair of rollers that compress the wet powder after compression by the preliminary of press unit
Data Source
AI summary
A battery electrode manufacturing device includes: a powder supply device that supplies an electrode composition as a wet powder containing an electrode active material and an electrolytic solution to a strip-shaped base film; a conveyance mechanism that conveys the base film on which the electrode composition supplied from the powder supply device is placed; a preliminary press device, that includes a pair of preliminary rollers, and that compresses the electrode composition supplied from the powder supply device to the base film; and a press device having a pair of rollers that compress the electrode composition after compression by the preliminary press device. The preliminary press device includes a plurality of the pair of preliminary rollers that compress the electrode composition in stages, and the gap between the pair of preliminary rollers is set to be larger than the gap between the pair of rollers.