Battery Cell Separator Sealing for Tab-Edge Adhesion
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Solution Overview
Problem
Conventional battery cell sealing technologies experience separator folding and interference issues due to the use of straight-shaped sealing members, resulting in weak adhesive forces at corner portions and potential damage during the sealing process.
Innovation Solution
A battery cell design featuring larger rectangular separators with protruding tabs and a sealing member with a folded portion, allowing for stronger adhesion at tab edges and preventing interference with electrode plates, along with a manufacturing method that includes forming recessed corners on the negative electrode plate to avoid sealing member interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a straight sealing member is used for separator adhesion, then the sealing process is simple, but the adhesive force at corner portions is weak causing separator folding
Solution Approach 1:
The sealing member is designed with a folded portion that creates a curved or bent shape instead of a straight line, allowing the sealing member to conform to the corner geometry of the separator and apply uniform adhesive force across the entire separator edge including corners
2Device complexity
If a straight sealing member is used for separator adhesion, then the device structure is simple, but separator folding occurs due to insufficient adhesion at corners
Solution Approach 1:
The folded portion of the sealing member creates a curved configuration that matches the corner geometry of the separator, ensuring stable adhesion and preventing separator folding while maintaining reasonable device complexity
3Reliability
If the sealing member presses during sealing, then adhesion is achieved, but interference with electrode plates occurs causing potential damage
Solution Approach 1:
The sealing member is designed with different geometric configurations at different locations: the folded portion targets the separator corners for adhesion, while the main body is positioned to clear the electrode plates, allowing localized adhesion action without causing harmful interference to other components
Data Source
AI summary
A battery cell includes an electrode assembly formed by stacking a first separator, a negative electrode plate, a second separator, and a positive electrode plate; a negative electrode tab protruding from the negative electrode plate; and a positive electrode tab protruding from the positive electrode plate, the first and second separators have larger size in all four surfaces than the negative and positive electrode plates, and the whole of the tab edge portions of the first and second separators located on the surface on which the positive electrode tab and the negative electrode tab are formed and a part of the both side edge portions connected to the tab edge portion are adhered to each other, the inward adhesion width at the tab edge portion is smaller than the inward adhesion width at both ends where the tab edge portion and the both side edges portions are connected.