Electrode Assembly Overhang Layout for Uniform Battery Height
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Solution Overview
Problem
Existing secondary batteries, particularly cylindrical batteries, face issues with height uniformity of the electrode assembly, which affects capacity uniformity and assembly compatibility with housing, leading to potential lithium plating and reduced energy density.
Innovation Solution
The electrode assembly design includes specific overhang distances (Lp and Ln) for the negative and positive coated areas, along with controlled standard deviations and ratios, to enhance height uniformity, ensuring consistent electrode assembly heights and improved energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the electrode assembly is wound with traditional stacking methods, then the manufacturing process is simple, but the height uniformity of the electrode assembly is poor
Solution Approach 1:
The patent applies parameter changes by precisely controlling the overhang distances (Lp and Ln) of the negative and positive coated areas relative to the current collectors. By optimizing these dimensional parameters within specific ranges, the electrode assembly achieves uniform height without complex additional structures, directly resolving the contradiction between manufacturing precision and device complexity.
2Reliability
If the electrode assembly height is not uniform, then the manufacturing process is simpler, but lithium plating occurs and capacity consistency deteriorates
Solution Approach 1:
The patent controls the overhang parameters Lp and Ln within specific ranges to ensure uniform electrode assembly height. This parameter optimization prevents lithium plating during charging and discharging processes, improving reliability and capacity consistency while maintaining manufacturing simplicity through conventional winding techniques.
Solution Approach 2:
The patent applies preliminary anti-action by pre-controlling the overhang distances of the coated areas before the battery operates. By designing the electrode structure with appropriate overhang margins, the patent prevents harmful lithium plating from occurring in the first place, rather than attempting to mitigate it after the fact.
3Adaptability or versatility
If the electrode assembly height varies significantly, then manufacturing is easier, but assembly compatibility with standardized housings is poor
Solution Approach 1:
The patent achieves adaptability to standardized housings by controlling the height uniformity of the electrode assembly through optimized overhang parameters. By maintaining consistent height across the electrode assembly, it becomes compatible with standardized housing dimensions and assembly processes, resolving the contradiction between manufacturing precision and adaptability.
Data Source
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AI summary
A secondary battery (100) is provided, including an electrode assembly (120) which includes a negative pole sheet (11), a first separator (12), a positive pole sheet (13), and a second separator (14). The negative pole sheet (11) includes a negative coated area (211) and a negative tab (311) protruding from the negative coated area (211). The positive pole sheet (13) includes a positive coated area (213) and a positive tab (313) protruding from the positive coated area (213). A direction from the negative tab (311) to the positive tab (313) is a height direction (H). Along the height direction (H), an upper end of the negative coated area (211) overhangs an upper end of the positive coated area (213). Along a direction away from the height direction (H), a lower end of the negative coated area (211) overhangs a lower end of the positive coated area (213).