Battery Electrode Tab Layout for Needle-Penetration Short-Circuit Risk
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Solution Overview
Problem
Lithium-ion batteries have a safety vulnerability due to a large exposed conductive region on the current collector, which increases the risk of short circuits during needle penetration and other mechanical stresses.
Innovation Solution
The design of the electrochemical apparatus includes a current collector with a first active material layer and a first insulation layer, where the orthographic projection of the insulation layer surrounds the exposed conductive region of the tab, reducing the exposed conductive area and enhancing the stability of the connection between the tab and the electrode plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a large exposed conductive region is reserved on the current collector for tab welding position, then the tab welding is facilitated, but the safety risk of short circuit increases during needle penetration
Solution Approach 1:
The current collector surface is segmented into multiple regions: a first region with active material layer, a second region with insulation layer, and a first portion of a third region as exposed conductive region. This segmentation allows the exposed conductive region to be isolated and controlled, reducing short circuit risk while maintaining tab welding capability.
Solution Approach 2:
Different regions of the current collector are given different properties: the second region has insulation layer coverage to prevent short circuits, while the first portion of the third region remains exposed for tab welding. This local differentiation of properties allows simultaneous achievement of safety and manufacturability.
2Object-affected harmful factors
If the exposed conductive region is reduced to improve safety, then the short circuit risk decreases, but the tab welding position availability may be affected
Solution Approach 1:
The current collector surface is divided into functional zones where the first portion of the third region provides sufficient exposed area for tab welding while being spatially separated from other conductive regions by the insulation layer, thus maintaining welding accessibility while minimizing overall exposed conductive area.
Solution Approach 2:
The insulation layer acts as an intermediary element that separates the exposed conductive region from other conductive areas. This mediator allows the exposed region to remain accessible for welding while preventing harmful electrical interactions with surrounding conductive structures.
3Reliability
If the orthographic projection of the insulation layer surrounds the exposed conductive region, then the electrical insulation is improved, but the device complexity increases
Solution Approach 1:
The insulation layer is applied selectively only in the second region where it is needed for electrical isolation, rather than covering the entire current collector. This localized application achieves the required electrical insulation while minimizing the added complexity and material usage.
Solution Approach 2:
The insulation layer covers the second region completely to ensure full electrical isolation of the exposed conductive region, providing sufficient (slightly excessive) insulation coverage that guarantees safety while the surrounding structure remains relatively simple.
Data Source
AI summary
An electrochemical apparatus and an electronic apparatus are disclosed. The electrochemical apparatus includes an electrode plate and a tab, where the electrode plate includes a current collector, a first active material layer, and a first insulation layer. The current collector includes a first region, a second region, and a first portion of a third region, where the first region is provided with the first active material layer, and the second region is provided with the first insulation layer. Along a thickness direction of the current collector, an orthographic projection of the second region at least partially surrounds an orthographic projection of the first portion of the third region. In this way, the electrode plate has a small exposed conductive region. This can reduce the safety risk such as a short circuit risk caused during a needle penetration operation on the electrochemical apparatus.