Battery Electrode Tab Structure to Prevent Welding Through
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Solution Overview
Problem
The phenomenon of electrode assembly damage during production and assembly of battery cells leads to poor production quality, affecting the product qualification rate of battery cells.
Innovation Solution
An electrode assembly design with two electrode sheets of opposite polarities, a separation member, and tab portions with protrusions, arranged in a specific direction to enhance thickness and stability, reducing the risk of welding through and improving assembly quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the tab portions are stacked without protrusions, then the assembly is simple, but the local thickness is small causing welding through risk
Solution Approach 1:
The patent applies local quality by adding protrusions only to the tab portions where increased thickness is needed, rather than uniformly thickening the entire tab. The protrusions are specifically positioned at the stacking interfaces of tab portions to localize the thickness enhancement exactly where welding through risk occurs, maintaining simplicity elsewhere in the structure.
Solution Approach 2:
The patent resolves the thickness issue by transitioning from a two-dimensional stacking arrangement to a three-dimensional structure with protrusions extending in the thickness direction. This dimensional change allows the tab portions to maintain their compact stacked layout while achieving sufficient local thickness through the added protrusion dimension.
2Reliability
If the tab portions are made thicker to prevent welding through, then welding reliability improves, but the assembly complexity increases
Solution Approach 1:
The protrusions are strategically positioned only at critical welding locations on the tab portions, providing localized thickness enhancement where welding reliability is most needed. This avoids unnecessary complexity in regions where the tab structure does not require additional thickness protection.
Solution Approach 2:
The tab structure is segmented into multiple tab portions with protrusions, allowing the thickness enhancement to be distributed across discrete segments rather than requiring a monolithic thickening of the entire tab. This segmentation enables targeted reliability improvement without proportionally increasing overall complexity.
3Manufacturing precision
If multiple protrusions are added to increase tab thickness, then welding through risk reduces, but the manufacturing complexity increases
Solution Approach 1:
The protrusions are positioned only at specific critical locations on the tab portions where thickness uniformity is most needed during stacking. This localized approach achieves the necessary manufacturing precision without adding protrusions to every surface, thereby limiting the increase in manufacturing complexity to only the essential areas.
4Volume of moving object
If the tab portions are stacked closely without protrusions, then the assembly is compact, but damage to electrode assembly occurs
Solution Approach 1:
The patent maintains compact volume by keeping the tab portions closely stacked in the primary plane, then uses the protrusions extending in the thickness direction to provide protective spacing and structural reinforcement. This dimensional approach prevents damage without requiring increased lateral spacing that would expand the overall volume.
Solution Approach 2:
The protrusions act as pre-positioned protective elements that cushion and prevent damage to the electrode assembly during assembly operations. By having these protective features in place before assembly occurs, the structure is preemptively protected against potential damage from handling or welding operations.
Data Source
AI summary
An electrode assembly, a battery cell, a battery, and an electric device are provided. The electrode assembly includes two electrode sheets having opposite polarities and a separator used for separating the two electrode sheets, the two electrode sheets and the separator being wound in a winding direction to form a main body and two tabs. The tabs and the main body are arranged in a first direction; each tab comprises a plurality of tab portions arranged at intervals in the winding direction; the tab portions are bent relative to the first direction; at least parts of the plurality of tab portions are stacked in the first direction; and a protrusion is formed on at least one side of each tab portion in the thickness direction thereof.