Dual Sealing Cap Assembly for Cylindrical Battery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cylindrical secondary batteries with jelly-roll type electrode assemblies face issues of electrolyte leakage due to low adhesion strength between metal interfaces, leading to potential explosions from internal shorts and external impacts.
Innovation Solution
A cap assembly design where the safety vent and current interrupt device (CID) are fixed together in a fitting state, with the CID seated in the inclined or terraced portion of a gasket, enhancing the bonding strength and providing additional sealing between the CID and the gasket, thus preventing electrolyte leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the CID is simply placed in the cap assembly without additional fixation structures, then the device complexity is reduced, but the reliability of fixing the CID and preventing electrolyte leakage deteriorates
Solution Approach 1:
The patent introduces a gasket as an intermediary component between the CID and the cap assembly. The gasket includes an inclined portion that receives the support unit of the CID, creating a mechanical interlocking structure. This intermediary element enhances the fixation reliability without significantly increasing overall device complexity, as the gasket serves multiple functions including sealing and mechanical support.
Solution Approach 2:
The patent adds a dimensional feature to the gasket by creating an inclined portion (a sloped surface) rather than using a flat sealing surface. This dimensional change allows the support unit of the CID to be seated at an angle, providing mechanical retention through the inclination. This geometric feature prevents the CID from dislodging while maintaining a relatively simple overall structure.
2Strength
If the support unit of the CID is seated in the inclined portion of the gasket, then the bonding strength and sealing efficacy are improved, but the device complexity increases
Solution Approach 1:
The patent merges multiple functions into the gasket component: it serves as both the sealing element and the mechanical fixation structure for the CID. The inclined portion of the gasket simultaneously provides the sealing surface and the retention feature for the support unit. This consolidation of functions increases bonding strength without proportionally increasing device complexity, as one component performs multiple roles.
Solution Approach 2:
The patent applies a localized geometric feature (the inclined portion) to a specific area of the gasket where the CID needs to be retained. Rather than making the entire gasket complex, only a localized region has the inclined geometry necessary for securing the support unit. This localized approach enhances bonding strength at the critical interface while keeping the overall structure relatively simple.
Data Source
AI summary
The present invention relates to a cap assembly and a battery including the same. More particularly, the present invention relates to a cap assembly for a cylindrical secondary battery, in which the support unit of a current interrupt device (CID) is seated in the inclined portion or the terraced portion of a gasket and thus the battery is dually sealed, thereby preventing the leakage of an electrolyte, and a cylindrical secondary battery including the cylindrical secondary battery. The cap assembly of the present invention is dually sealed for the leakage of an electrolyte. Accordingly, there is an advantage in that the safety of the battery can be greatly improved because the electrolyte is rarely leaked although the battery is shocked because of dropping.