Battery Cell End Cap Recess Structure for Defect-Resistant Welding
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Solution Overview
Problem
Existing battery cell manufacturing processes often result in welding defects during the connection of electrode terminals and tabs, which can compromise the airtightness and normal operation of battery cells.
Innovation Solution
The battery cell design incorporates an end cap with a recessed area and an arc striking portion, where the welding portion is positioned on the arc striking portion or the thicker face, reducing the risk of welding defects and ensuring that any defects do not affect the airtightness by being on a thicker surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding is performed on a flat surface without a recess, then the welding process is simple, but welding defects occur frequently during arc striking and extinguishing
Solution Approach 1:
The end cap surface is segmented into different regions: a recessed area for stable welding and a surrounding flat area for arc striking and extinguishing. This segmentation allows each region to serve its specific function optimally, reducing welding defects while maintaining structural integrity.
Solution Approach 2:
The recessed area acts as an intermediary structure between the welding zone and the arc striking zone. It provides a transition region that stabilizes the welding process and prevents defects from propagating to critical areas.
2Reliability
If the arc striking portion is made with a long slope, then welding defects are reduced, but the end cap strength and current area are reduced
Solution Approach 1:
The arc striking portion is designed with a specific slope angle (15-45 degrees) and height (≥0.4mm) to provide local quality improvement where needed for welding stability, while maintaining the overall strength of the end cap. The localized recessed structure provides welding stability without compromising the global structural integrity.
3Strength
If the arc striking portion is made with a steep slope, then the end cap strength is maintained, but welding defects cannot be effectively prevented
Solution Approach 1:
The slope angle of the arc striking portion is optimized to be between 15 and 45 degrees, and the height is set to at least 0.4mm. These parameter changes create the ideal geometry for both maintaining end cap strength and preventing welding defects during the welding process.
Data Source
AI summary
A battery cell includes an end cap and a welding portion. The end cap is provided with a recess recessed relative to a first face facing away from the inside of the battery cell, and an arc striking portion is arranged between the recess and the first face. The arc striking portion is a slope and has a first end and a second end opposite to each other, the thinner first end is connected to the recess, the thicker second end is connected to the first face. The welding portion is configured to connect the end cap to a tab of the battery cell, a central portion of the welding portion is located in the recess, and an end portion of the welding portion is located on the arc striking portion or the first face.