Electrode Tab Indentation for Lithium Battery Rolling Integrity
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Solution Overview
Problem
Conventional lithium secondary batteries face issues with the vulnerability of electrode tabs during the rolling process due to uncoated regions, leading to potential breakage and reduced active material capacity.
Innovation Solution
The introduction of indented portions at the lower ends of the electrode tabs reduces the uncoated region, alleviating stress and improving processability, while maintaining a coupling space for electrode leads, thereby enhancing the stability and capacity of the battery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an uncoated region is provided at the electrode tab to secure a connection space for electrode lead, then the electrode lead can be connected to the electrode tab, but the uncoated region becomes vulnerable to physical impact and breakage during hot rolling of the electrode material mixture
Solution Approach 1:
The patent applies preliminary action by pre-forming indented portions at the lower ends of the electrode tab before the electrode material mixture is applied. This creates a structural reinforcement that prevents breakage during subsequent rolling processes while maintaining the necessary uncoated region for electrode lead connection. The indented portions are formed in advance to anticipate and prevent the vulnerability issue during manufacturing.
2Ease of manufacture
If the area of the uncoated region is increased to secure a connection space, then the electrode lead connection is ensured, but the amount of active material accommodated by the electrode plate relatively decreases
Solution Approach 1:
The patent applies local quality by concentrating the uncoated region specifically at the lower ends of the electrode tab where the indented portions are formed, rather than having a large uncoated area throughout. This localized approach provides sufficient connection space for electrode leads while minimizing the loss of active material accommodation capacity in other regions of the electrode plate.
3Quantity of substance
If the uncoated region is reduced to increase active material capacity, then more active material can be accommodated, but the connection space for electrode lead may be compromised
Solution Approach 1:
The patent forms indented portions in advance at the lower ends of the electrode tab before applying the electrode material mixture. This preliminary structuring ensures that even with a minimized uncoated region, there is sufficient localized space and structural support for electrode lead connection, thus maintaining manufacturing ease while maximizing active material capacity.
Data Source
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AI summary
The present invention relates to an electrode assembly including at least two electrode plates and a separator interposed between the electrode plates, wherein indented portions are formed from lower ends of opposite sides of the electrode tab in an opposite direction to an externally extending direction of the electrode tab in a side of the electrode body in which the electrode tab externally extends, in the electrode plates.