Battery Tab Insulation Fold-Over to Reduce Joining Stress
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Solution Overview
Problem
Existing battery designs apply a load to the tab portion and the joined portion between the tab portion and the current collector when joining overlapping portions of an insulating sheet, leading to decreased reliability.
Innovation Solution
A battery design that includes an insulating sheet disposed between the electrode assembly and the battery case, with a fold-over portion where the current collector faces the side surface of the battery case, and a joined portion formed by folding the insulating sheet over the tab portion to alleviate stress on the tab and joined areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the insulating sheet is joined by heat-sealing using the current collector as a pad, then the insulating sheet can be securely fixed, but a load is applied to the tab portion and the joined portion between the tab portion and the current collector, resulting in decreased reliability
Solution Approach 1:
A dedicated sealing member (insulating sheet sealing portion) is introduced as an intermediary component between the insulating sheet and the current collector. This sealing member performs the heat-sealing function while preventing direct load transmission to the tab portion and its joined portion, thus resolving the contradiction between securing the insulating sheet and maintaining reliability of the tab connection.
2Stability of the object's composition
If the insulating sheet is folded and joined to cover the electrode assembly, then the electrode assembly is protected and secured, but stress is concentrated on the tab portion and joined portion, reducing structural integrity
Solution Approach 1:
The sealing member acts as a mediator that distributes the securing function away from the tab portion. By placing the sealing member between the insulating sheet and the current collector, the structural load is transferred to the sealing member rather than concentrating stress on the tab portion and its joined portion, thereby maintaining structural integrity while still securing the electrode assembly.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design enhances the reliability of the battery by reducing stress on the tab and joined portions, thereby improving the overall structural integrity and performance.
Implementation Method 1
Portions of the overlapping third sections on the open end side are heat-sealed together while using an intermediate part of the current collector as a pad
Data Source
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AI summary
An electrode assembly (20) has a positive electrode plate (200) and a negative electrode plate (250). The battery case (10) accommodates the electrode assembly (20). A tab portion (21) is provided on at least one of the positive electrode plate (200) and the negative electrode plate (250) and extends on a side of the electrode assembly (20). A current collector is connected to the tab portion (21). An insulating sheet (50) is disposed between the electrode assembly (20) and the battery case (10) and has a fold-over portion (550) between the battery case (10) and the current collector. The current collector faces a side surface of the battery case (10) with the tab portion (21) being folded. A joined portion (560) at which portions of the insulating sheet (50) are joined to each other is formed in the fold-over portion (550).