Button Cell Vent Structure for Internal Gas Pressure Relief
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Solution Overview
Problem
Conventional button cells are prone to explosion due to increased internal pressure caused by gas generation from short circuits within the case.
Innovation Solution
A button cell design featuring a terminal plate with a vent portion recessed from its rear surface, allowing gas to be discharged externally through a through-hole, preventing pressure buildup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the case is sealed to protect the electrode assembly, then protection is improved, but gas discharge capability deteriorates leading to pressure buildup and explosion risk
Solution Approach 1:
The bonding layer serves as an intermediary component between the cap plate and terminal plate. It provides both sealing protection and gas discharge functionality through its viscoelastic properties, allowing it to seal during normal operation but deform to create discharge paths when gas pressure builds up
Solution Approach 2:
The bonding layer's physical state changes under different pressure conditions. During normal operation, it maintains a sealed state. When gas pressure increases, the bonding layer deforms and changes its structural parameters to create discharge channels, allowing gas to escape while maintaining electrical insulation
2Strength
If the terminal plate is made thick for structural strength, then strength is improved, but gas discharge capability deteriorates
Solution Approach 1:
The terminal plate exhibits different thickness characteristics at different locations. The main body maintains sufficient thickness for structural strength and electrical insulation, while the vent portion has reduced thickness to facilitate gas discharge. This local variation in thickness allows simultaneous achievement of strength and gas discharge capabilities
Solution Approach 2:
The terminal plate is segmented into functionally distinct regions: a thick main body for structural support and electrical insulation, and a thinner vent portion for gas discharge. This segmentation allows each region to be optimized for its specific function without compromising the other
3Object-generated harmful factors
If the vent portion is made thin for easy gas discharge, then gas discharge is improved, but electrical insulation deteriorates
Solution Approach 1:
The bonding layer acts as an intermediary insulating layer between the cap plate and the vent portion of the terminal plate. It provides electrical insulation while allowing mechanical deformation for gas discharge, resolving the conflict between thinness for discharge and insulation requirements
Data Source
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AI summary
According to the invention, a button cell (100) comprises an electrode assembly (100), a case (200), a cap plate (300) and a terminal plate (400), wherein, in order to evacuate cases building within the button cell (1000), the terminal plate (400) comprises with a vent portion (430).