Outer Can Bent Portion Sealing Reliability
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Solution Overview
Problem
Existing power storage devices, such as lithium ion batteries, face challenges in maintaining high airtightness and sealing reliability, especially with increasing capacity and output demands, necessitating improved sealing mechanisms to prevent moisture ingress and enhance overall device reliability.
Innovation Solution
The power storage device incorporates an annular groove portion in the outer can and a bent portion in the sealing member, with the bent portion's wall thickness being thicker than the circumferential edge, securely holding the sealing member from both sides, and a thicker far end portion to enhance sealing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the upper end portion of the outer can is bent inward to seal the opening, then sealing reliability is improved, but the wall thickness at the bent portion decreases due to thinning during bending
Solution Approach 1:
The patent applies local quality by creating a thick-walled portion at the bent end through localized material accumulation during the bending process. This thick-walled portion is specifically positioned where maximum stress occurs during sealing, providing enhanced strength and reliability at the critical sealing location while maintaining thinner walls in non-critical areas to reduce overall weight and material usage.
Solution Approach 2:
The patent employs preliminary action by pre-forming a thick-walled portion at the intended bent end location before the actual bending operation. This pre-formed thick section ensures that when bending occurs, the critical sealing area has sufficient material thickness to prevent cracking and maintain structural integrity, thereby ensuring reliable sealing from the outset.
2Reliability
If the outer can is bent inward to hold the sealing member, then sealing performance is improved, but waving or deformation may occur at the bent portion
Solution Approach 1:
The patent applies local quality by creating a thick-walled portion at the bent end through localized material accumulation during the bending process. This thick-walled portion is specifically positioned where maximum stress occurs during sealing, providing enhanced strength and reliability at the critical sealing location while maintaining thinner walls in non-critical areas to reduce overall weight and material usage.
Solution Approach 2:
The patent employs preliminary action by pre-forming a thick-walled portion at the intended bent end location before the actual bending operation. This pre-formed thick section ensures that when bending occurs, the critical sealing area has sufficient material thickness to prevent cracking and maintain structural integrity, thereby ensuring reliable sealing from the outset.
Data Source
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AI summary
Comprised are: an electrode body (10); a cylinder (21); an outer can (20) that has an opening formed at one end of this cylinder (21), and that houses the electrode body (10); and a sealing member (24) that closes the opening. In the opening of the cylinder (21), a ring-shaped groove (23) is formed recessed inward, a bending part (210) bent inward is formed in the margin part of the opening, the peripheral part of the sealing member (24) is sandwiched from both sides by the groove (23) and the bending part (210), and the thickness of a bent part that leads from the margin part extending in the axial direction of the outer can (20) to the bending part (210) that extends facing inward is thicker than at least a portion of the bending part (210).