Cylindrical Battery Vent Structure for Internal Gas Discharge
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Solution Overview
Problem
Conventional cylindrical batteries face safety issues and performance reduction due to internal gas buildup during the activation process, which cannot be effectively removed.
Innovation Solution
A cylindrical battery design incorporating a metal can, an electrode assembly, a top cap with an exhaust hole, a safety vent, and a gas discharge member featuring a thin film structure composed of shape memory alloys to facilitate the removal of internal gases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional cylindrical battery structure is used, then the battery is easy to manufacture and has high energy density, but internal gas generated during activation cannot be removed causing safety issues and performance reduction
Solution Approach 1:
The top cap is segmented into multiple functional components: a vent hole for gas escape, a valve mechanism with membrane and cap for controlled venting, and a seal portion for maintaining pressure when needed. This segmentation allows the single top cap structure to simultaneously provide both safety venting and pressure maintenance functions, resolving the contradiction between ease of manufacture and safety.
Solution Approach 2:
A valve mechanism acting as an intermediary is introduced between the battery interior and exterior environment. The valve with its membrane and cap structure selectively controls gas flow - allowing gas to escape through the vent hole when pressure builds up during activation, while maintaining seal integrity during normal operation. This intermediary mechanism enables the battery to achieve both safety through gas removal and manufacturing simplicity through integration into the existing top cap.
2Use of energy by moving object
If a conventional cylindrical battery structure is used, then the battery has high energy density per weight, but internal gas buildup reduces performance and lifetime
Solution Approach 1:
The vent hole and valve mechanism are pre-configured in the top cap structure before battery activation. This preliminary arrangement ensures that when gas is generated during the activation process, there is already an established escape path available. The valve mechanism is pre-positioned to automatically respond to pressure changes, allowing gas to be removed at the appropriate moment during activation, thereby preventing performance degradation and extending battery lifetime while preserving high energy density.
3Strength
If the top cap is sealed to maintain pressure, then structural integrity is maintained, but gas generated during activation cannot be discharged
Solution Approach 1:
The top cap structure incorporates dynamic elements - specifically a valve mechanism with a membrane that can change state based on internal pressure conditions. When gas pressure builds up during activation, the membrane deforms or the valve opens to allow gas discharge through the vent hole. When pressure is normal, the valve remains sealed to maintain structural integrity. This dynamic response allows the structure to adapt between sealed and vented states, resolving the contradiction between maintaining strength and releasing harmful gas pressure.
Solution Approach 2:
The valve mechanism utilizes parameter changes in membrane deformation or cap positioning in response to pressure changes. As internal gas pressure increases during activation, the membrane deflects or the valve components move, triggering the opening of the vent hole. When pressure returns to normal levels, the membrane returns to its original position or the valve components re-seal, maintaining structural integrity. This parameter-based control enables automatic switching between sealed and vented states, simultaneously achieving strength maintenance and harmful gas discharge.
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 solution effectively discharges internal gases, enhancing battery performance and extending its lifespan by managing pressure and preventing explosions.
Implementation Method 1
a gas discharge member provided in the safety vent, and the gas discharge member may include a thin film part having at least two thin films
Data Source
AI summary
A cylindrical battery includes a metal can, an electrode assembly mounted in the metal can, a top cap closing an upper end of the metal can, the top cap having an exhaust hole, a safety vent located at an upper end of the electrode assembly, and a gas discharge member provided in the safety vent, in which the gas discharge member includes a thin film part having at least two thin films.