Secondary Battery Electrode Tape Layout for Uncoated Crack Suppression
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Solution Overview
Problem
Secondary batteries experience cracks due to continuous stress from high volume expansion during charging and discharging, leading to inefficient electron movement, increased resistance, and potential safety issues like heat generation and fire.
Innovation Solution
The electrode includes a coated portion with an active material layer and an uncoated portion, where a tab is fixed, and a tape is attached to the uncoated portion to alleviate stress and prevent cracks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the electrode structure includes a tab fixed to the electrode plate, then current collection is enabled, but continuous stress from volume expansion causes crack generation in the electrode
Solution Approach 1:
The patent applies a protective coating specifically to the uncoated portion of the electrode plate where the tab is attached, creating local reinforcement only where stress concentration occurs. This selective coating approach protects the vulnerable attachment region without affecting other areas of the electrode, resolving the contradiction between maintaining current collection functionality and preventing cracks at the tab interface.
Solution Approach 2:
The protective coating is applied in advance to the uncoated portion of the electrode plate before the tab attachment and subsequent charging-discharging cycles. This pre-applied coating acts as a cushioning layer that prevents crack initiation and propagation at the stress concentration point, allowing the tab to collect current reliably without causing electrode damage during repeated volume expansion.
2Reliability
If cracks occur in the electrode, then electron movement is blocked, but this leads to increased resistance and heat generation
Solution Approach 1:
The protective coating is selectively applied to the uncoated portion where the tab attaches, creating a localized protective zone. This prevents cracks specifically at the electron collection interface, ensuring continuous electron flow from the active material to the tab without blocking pathways, thereby maintaining low resistance and preventing heat generation from electron transport interruptions.
3Reliability
If the active material layer is applied on the substrate, then electrochemical activity is enabled, but the uncoated portion becomes vulnerable to stress and cracking
Solution Approach 1:
The patent creates a differentiated structure where the electrode plate has both coated portions (with active material for electrochemical activity) and uncoated portions (without active material but with protective coating for strength). The uncoated portion with protective coating serves as a reinforced attachment zone that resists stress from volume expansion while the coated portions maintain electrochemical functionality, thus resolving the contradiction between electrochemical activity and stress resistance.
Solution Approach 2:
The electrode plate is segmented into functionally distinct regions: coated portions for electrochemical reactions and uncoated portions for mechanical reinforcement and tab attachment. This segmentation allows each region to optimize its specific function without compromising the other, enabling both electrochemical activity and stress resistance in the overall electrode structure.
Data Source
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AI summary
The present disclosure relates to an electrode, and a technical problem to be solved is to provide an electrode capable of suppressing cracks from occurring in an uncoated portion. The present disclosure provides an electrode including: an electrode plate including a coated portion, which is a region in which an active material layer is applied on a substrate, and an uncoated portion, which is a region in which the active material layer is not applied on the substrate; a tab fixed to at least a part of the uncoated portion and protruding from the electrode plate; and a tape adjacent to the tab and attached onto the uncoated portion.