Dual Gasket Cap Assembly for Secondary Battery Impact Safety
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Solution Overview
Problem
Conventional cap assemblies for secondary batteries fail to ensure safety against external impacts, which can cause shorts and potentially lead to damage, firing, or explosion due to deformation of the battery can.
Innovation Solution
A cap assembly with a dual gasket structure, where a first gasket surrounds the current intercepting member and a second gasket surrounds the top cap, safety element, and safety vent, creating a horizontal space that prevents the current intercepting member from contacting the battery can, even under external impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional single gasket structure is used in the cap assembly, then the device complexity is low, but the safety against external impact is insufficient as the current intercepting member may contact the battery can causing shorts
Solution Approach 1:
The single gasket is divided into two separate gaskets: a first gasket that surrounds and supports the current intercepting member, and a second gasket that surrounds the top cap, safety element, and safety vent. This segmentation allows each gasket to perform its specific protective function independently, preventing the current intercepting member from contacting the battery can during external impacts while maintaining overall structural safety.
2Reliability
If the cap assembly is tightly sealed to the battery can, then the sealing performance is good, but the current intercepting member may contact the battery can under external impact causing internal shorts
Solution Approach 1:
The first gasket acts as an intermediary protective element between the current intercepting member and the battery can. It provides a physical barrier and support structure that prevents direct contact between these two components during external impacts, thereby preventing internal shorts while maintaining the sealed connection between the cap assembly and battery can through the second gasket.
3Quantity of substance
If the current intercepting member is positioned close to the battery can for compact design, then the battery capacity is increased, but the safety margin against impact-induced contact is reduced
Solution Approach 1:
The first gasket is positioned beforehand to surround and support the current intercepting member, creating a protective cushion between the member and the battery can. This pre-positioned protective structure ensures that even when the current intercepting member is placed close to the battery can for compact design and increased capacity, there remains a safety margin against impact-induced contact through the intervening gasket structure.
Data Source
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AI summary
A cap assembly for a secondary battery is coupled to an open end of a battery can receiving an electrode assembly in which a separator is interposed between cathode and anode plates, and includes a top cap disposed on an uppermost portion in a protrusive form to form a cathode terminal; a safety element disposed below the top cap to contact the top cap; a safety vent disposed to contact the safety element; a current intercepting member having an upper portion welded to a lower end of the safety vent and a lower portion capable of being connected to the electrode assembly; a first gasket surrounding an outer circumference of the current intercepting member; and a second gasket surrounding the rims of the top cap, the safety element, and the safety vent, and a lower end portion extending to surround the lower portion of the current intercepting member.