Electrode Rolling Roughness Control for Uniform Lithium Battery Coating
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Solution Overview
Problem
Existing methods for manufacturing electrodes for rechargeable lithium batteries face issues with electrolyte overflow, crack formation, and non-uniform thickness, leading to decreased battery capacity.
Innovation Solution
A method involving the use of rolling rolls with specific surface roughness and travel distance limits to prevent electrolyte overflow and crack formation, ensuring a uniform electrode thickness by replacing the first rolling roll with a second rolling roll when surface roughness exceeds 150% to 400% of the initial or travel distance reaches 5,000 to 7,000 km.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a rolling roll is used for electrode manufacturing, then electrode thickness uniformity is improved, but after extended use (5000-7000 km), the rolling roll surface roughness increases to 150%-400% of initial, causing electrolyte overflow and crack formation
Solution Approach 1:
The patent implements a dynamic replacement strategy where the rolling roll is monitored for surface roughness changes and replaced when it reaches 150%-400% of its initial roughness value or after 5000-7000 km of use. This dynamic approach maintains manufacturing precision while preventing the reliability degradation that occurs with extended roll usage.
Solution Approach 2:
The patent establishes specific parameter thresholds for roll replacement: surface roughness reaching 150%-400% of initial value or travel distance of 5000-7000 km. By monitoring and responding to these parameter changes, the system maintains both electrode thickness uniformity and prevents electrolyte overflow and crack formation.
2Productivity
If the rolling roll is used beyond the specified travel distance or roughness threshold, then productivity is maintained, but battery capacity decreases due to crack formation and electrolyte overflow
Solution Approach 1:
The patent performs preliminary replacement of the rolling roll before significant degradation occurs by establishing replacement thresholds at 150%-400% of initial surface roughness or 5000-7000 km travel distance. This preliminary action prevents crack formation and electrolyte overflow that would otherwise occur with extended use, thereby maintaining battery capacity while preserving manufacturing continuity.
3Productivity
If the rolling roll surface roughness increases, then the rolling process continues without interruption, but electrode cracks form and thickness uniformity deteriorates
Solution Approach 1:
The patent implements a feedback mechanism by continuously monitoring the rolling roll's surface roughness and comparing it against the initial value. When the roughness reaches 150%-400% of the initial value or after 5000-7000 km of use, the system triggers roll replacement, thereby maintaining electrode thickness uniformity while minimizing interruptions to manufacturing productivity.
Data Source
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AI summary
A method of manufacturing an electrode for a rechargeable lithium battery includes forming a coating layer of a slurry including a positive electrode active material on at least one surface of a current collector and rolling the current collector using a first rolling roll. The first rolling roll has an initial surface roughness Ra of 0.2 µm to 0.4 µm. The method includes replacing the first rolling roll with a second rolling roll when the surface roughness Ra of the first rolling roll ranges from 150% to 400% of the initial surface roughness Ra or a traveling distance of the first rolling roll is 5,000 km to 7,000 km.