Battery Cap Vent Sealing for Controlled Degassing and Leak Prevention
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Solution Overview
Problem
Secondary batteries are prone to abnormal phenomena such as gas generation, which can lead to fire or explosion, and existing designs do not adequately address the need to safely manage and prevent these occurrences.
Innovation Solution
A secondary battery design featuring a cap assembly with a vent hole and a sealing member that includes a degassing passage, allowing for the controlled release of gas and injection of electrolyte, while using an elastic sealing member to maintain electrical insulation and prevent leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a vent hole is formed in the cap assembly to release gas, then gas generation safety is improved, but electrical insulation and leakage prevention deteriorate
Solution Approach 1:
A sealing member is introduced as an intermediary component inserted into the vent hole. This sealing member allows gas to pass through while blocking electrolyte leakage and maintaining electrical insulation. The sealing member acts as a mediator that resolves the contradiction by enabling gas venting functionality while preventing the harmful effects of electrolyte leakage and electrical short circuits.
Solution Approach 2:
The sealing member is positioned specifically at the vent hole location to provide localized sealing. This local quality approach allows the vent hole to maintain its gas release function while the sealing member provides targeted protection against electrolyte leakage and electrical insulation issues only at the critical vent hole area.
2Reliability
If the sealing member is made elastic to maintain close contact with the vent hole, then leakage prevention is improved, but manufacturing precision deteriorates
Solution Approach 1:
The sealing member's material parameter is changed to be elastic, which allows it to deform and adapt to the vent hole dimensions. This elasticity compensates for variations in manufacturing precision during insertion, enabling the sealing member to achieve reliable close contact with the vent hole inner diameter even when insertion accuracy varies within acceptable tolerances.
3Reliability
If the head portion diameter is larger than the vent hole diameter to ensure sealing contact, then leakage prevention is improved, but device complexity deteriorates
Solution Approach 1:
The sealing member incorporates a dynamic structure with different diameter portions (head portion and tail portion) that allows it to adapt to the vent hole during insertion. The head portion with larger diameter ensures sealing contact by engaging with the vent hole inner diameter, while the tapered transition to the smaller tail portion simplifies the overall structure and facilitates easy insertion without requiring complex assembly mechanisms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design effectively manages gas buildup, preventing safety accidents and maintaining electrical integrity by allowing controlled degassing and electrolyte injection, thereby enhancing the stability and safety of the battery.
Implementation Method 1
the sealing member may be formed of an elastic material, and inserted in close contact with an inner diameter of the vent hole
Data Source
AI summary
A secondary battery includes an electrode assembly, a case accommodating the electrode assembly, the case including an opening on one side thereof, a cap assembly seated in the opening of the case, the cap assembly including a vent hole penetrating the cap assembly in a first direction, and a sealing member in the vent hole, the sealing member including a degassing passage in the first direction.