Secondary Battery Safety Vent Structure for Gas Release and Rigidity
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Solution Overview
Problem
Conventional cylindrical secondary batteries face limitations in vibration resistance and structural rigidity due to spatial restrictions on the safety vent, which impede effective gas discharge when internal pressure increases.
Innovation Solution
A secondary battery design featuring a safety vent with a notch portion that is closed, allowing full opening for gas discharge, and a crimping joint for enhanced structural integrity, along with a manufacturing method that includes forming a curling portion to prevent damage during crimping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the safety vent is provided with a notch portion that is open, then gas discharge is facilitated, but vibration resistance and structural rigidity deteriorate
Solution Approach 1:
The gap in the safety vent is closed in advance during manufacturing (before the battery operates) to ensure structural integrity. When gas discharge is needed, the safety vent opens fully despite the closed gap, because the closing was done preliminarily and does not prevent opening under pressure.
Solution Approach 2:
The physical state of the safety vent gap is changed from open to closed during manufacturing. This parameter change (closing the gap) improves vibration resistance while the safety vent's ability to open fully under pressure remains intact, resolving the contradiction between structural rigidity and gas discharge capability.
2Volume of moving object
If the safety vent is constrained by spatial restrictions, then structural compactness is improved, but gas discharge effectiveness deteriorates
Solution Approach 1:
The safety vent is prepared in advance with a closed gap structure that does not prevent full opening under pressure. This preliminary closing allows the battery to maintain compact dimensions while the safety vent can still open completely when needed for effective gas discharge.
3Ease of manufacture
If the safety vent structure is simplified, then manufacturing ease is improved, but structural rigidity deteriorates
Solution Approach 1:
The gap closing is performed as a preliminary step during safety vent manufacturing, integrating the rigidity enhancement into the manufacturing process itself. This maintains manufacturing simplicity while achieving the desired structural rigidity through the closed gap configuration.
Data Source
AI summary
A secondary battery according to an embodiment of the present disclosure includes an electrode assembly, a battery case that houses the electrode assembly and has an opened upper party, and a cap assembly that is coupled to the opened upper part of the battery case.The cap assembly comprises a safety vent formed with a notch portion, and a gap formed by the notch portion is closed.