Secondary Battery Electrode Tab Structure With Minimal Non-Coating Area
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Solution Overview
Problem
Existing secondary batteries face issues with reduced battery capacity and mechanical strength due to the formation of non-coating portions required for attaching multiple electrode tabs, which also increase electrical resistance.
Innovation Solution
A secondary battery design featuring a notching tab part extending from the coating portion of the electrode collector, forming multiple overlapping layers, minimizing non-coating areas and enhancing mechanical strength through a bent and bonded connection to the can member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If multiple electrode tabs are attached to reduce electrical resistance, then electrical resistance decreases, but battery capacity is lowered due to increased non-coating portions
Solution Approach 1:
The electrode tab is segmented into multiple tabs (first electrode tab and second electrode tab) that are separated by a predetermined distance. This segmentation allows multiple connection points to the current collector without requiring large non-coating portions, as each tab can be independently positioned to minimize active material loss while maintaining low electrical resistance through distributed connectivity.
2Loss of energy
If multiple electrode tabs are attached to reduce electrical resistance, then electrical resistance decreases, but mechanical strength is reduced
Solution Approach 1:
The electrode tabs are designed with extended portions that protrude from the wound electrode assembly before sealing. This preliminary configuration allows the tabs to be pre-positioned and secured to the current collector in a manner that distributes mechanical stress, preventing tab breakage while maintaining low electrical resistance through optimal positioning.
3Ease of manufacture
If non-coating portions are increased to attach multiple electrode tabs, then ease of manufacture improves, but battery capacity is lowered
Solution Approach 1:
The electrode structure implements local quality by having coating portions and non-coating portions strategically distributed. The non-coating portions are minimized and localized only where necessary for tab attachment, while the majority of the electrode surface maintains active material coating. This allows easy manufacture through standard tab attachment processes while preserving battery capacity by limiting non-active material areas.
4Strength
If electrode tabs are notched and extended to form multiple layers, then mechanical strength increases, but device complexity increases
Solution Approach 1:
The electrode assembly is wound into a cylindrical or spiral configuration, creating a curved, multi-layered structure. The electrode tabs extend from this wound structure, naturally forming multiple overlapping layers that provide mechanical strength. This curved geometry achieves enhanced strength through the wound configuration itself rather than requiring complex notching or additional structural elements, thereby limiting device complexity.
Data Source
AI summary
An electrode for a secondary battery may include an electrode collector, a coating portion having an active material coated on the electrode collector, a first non-coating portion on which the active material is not applied to the electrode collector, and a second non-coating portion on which the active material is not applied to the electrode collector. The first non-coating portion may be adjacent to the coating portion in a width direction perpendicular to a longitudinal direction of the electrode collector, the first non-coating portion having a longitudinal dimension extending along the longitudinal direction, the first non-coating portion configured to be bent and electrically coupled to a can member of the secondary battery. The second non-coating portion may be adjacent to the coating portion in the longitudinal direction. The electrode may be stacked into a stack with a separator and a second electrode of an opposite polarity than the electrode.