Chamfered Protective Tape for Battery Cell Tab Sealing
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Solution Overview
Problem
Lithium secondary batteries face issues with pressure deviation and non-uniform adhesive properties due to the uneven attachment of protective tapes between cathode and anode tabs, leading to variations in internal resistance and sealing problems.
Innovation Solution
A battery cell design featuring chamfered protective tapes made of casted polypropylene, covering both the cathode and anode tabs' bent portions, with chamfered ends to ensure even coverage and prevent sealing interference, manufactured using a simple Y-shaped punch method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If protective tape is attached only to the anode portion, then the attachment process is simple, but pressure deviation occurs between cathode and anode resulting in non-uniform adhesive property
Solution Approach 1:
The protective tape is designed with different functional zones: a first adhesive layer for attachment to the electrode assembly and a second adhesive layer for attachment to the battery case. This local differentiation allows the tape to provide uniform pressure distribution across both cathode and anode portions while maintaining ease of manufacture through a standardized attachment process.
2Manufacturing precision
If protective tape covers the top area of electrode assembly, then pressure deviation is reduced, but the tape edges may interfere with battery case sealing
Solution Approach 1:
The protective tape features asymmetric chamfering at its ends, creating inclined surfaces that angle away from the battery case sealing area. This asymmetric design allows the tape to extend far enough to cover the top area of the electrode assembly and provide uniform pressure distribution, while the chamfered edges prevent interference with the sealing process by directing the tape's boundary away from the sealing interface.
3Manufacturing precision
If protective tape is extended to cover both cathode and anode tabs, then adhesive uniformity improves, but manufacturing complexity increases
Solution Approach 1:
The protective tape is designed as a universal component that simultaneously serves multiple functions: it provides mechanical protection to both cathode and anode tabs, ensures uniform pressure distribution across the entire top area of the electrode assembly, and prevents sealing interference through its chamfered design. This multi-functionality is achieved through a single standardized tape structure with differentiated adhesive layers, avoiding the need for separate components for each function and thereby reducing overall manufacturing complexity.
Data Source
AI summary
The present disclosure relates to a battery cell for a secondary battery in which an electrode assembly including a cathode, an anode, and a separator interposed between the cathode and the anode is incorporated in a battery case.The cathode has a cathode tab extending from a cathode current collector formed on one side, and the anode has an anode tab extending from an anode current collector formed on one side. At a top area of the electrode assembly where the cathode tab and the anode tab protrude, the cathode tab and the anode tab each have a first bent portion and a second bent portion that are bent in a v shape.A protective tape is attached to the first bent portion, the second bent portion, and top areas of the electrode assembly adjacent to the first and second bent portions so as to cover them, andupper parts at both ends of the protective tape are chamfered.