Battery Cell Venting Structure for Faster Thermal Runaway Gas Release
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Solution Overview
Problem
Existing battery cells face safety hazards due to limited gas exhausting rates during thermal runaway, often resulting in blocked pressure relief mechanisms and increased risk of explosion or fire, primarily because the space available for gas flow is restricted and the pressure relief mechanism is prone to being obstructed by internal components.
Innovation Solution
The battery cell design incorporates a duct on the support member to guide gas into a pressure relief mechanism, with a recess on the side plate to increase spacing and accommodate the electrode assembly, allowing for a larger duct size and enhanced gas exhausting rate, thereby improving safety by ensuring timely pressure release during thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the space for gas flow is increased to improve gas exhausting rate, then safety is improved, but the volume available for electrode assembly is reduced, decreasing battery capacity
Solution Approach 1:
The side plate is segmented into multiple regions: a first recess for accommodating the electrode assembly, a second recess for forming the duct, and a third recess for the pressure relief mechanism. This segmentation allows each region to serve its specific function independently, enabling the duct to have sufficient cross-sectional area for gas flow without compromising the space available for the electrode assembly, thus resolving the contradiction between safety and battery capacity.
Solution Approach 2:
The duct is formed by utilizing the thickness dimension of the side plate through the second recess, rather than reducing the planar area. This dimensional approach allows the duct to have adequate cross-sectional area for gas flow while maintaining the overall footprint available for electrode assembly accommodation, effectively resolving the space conflict between safety requirements and capacity optimization.
2Reliability
If a larger duct is provided to increase gas exhausting rate, then safety is improved, but the structural complexity increases
Solution Approach 1:
The duct is merged with the side plate structure itself, formed by the second recess rather than being a separate component. This integration eliminates the need for additional parts and assembly steps, reducing structural complexity while still providing the necessary duct size for effective gas exhaustion and maintaining safety.
3Productivity
If the spacing between electrode assembly and side plate is increased to accommodate duct, then gas flow is improved, but the overall battery cell volume increases
Solution Approach 1:
The side plate is designed with local quality variations through different recesses: the first recess maintains close spacing for electrode assembly accommodation, the second recess creates localized thickness reduction for the duct, and the third recess provides space for the pressure relief mechanism. This localized approach allows gas flow improvement through the duct without increasing the overall battery cell volume, as the duct utilizes the side plate's thickness rather than expanding the external dimensions.
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
This design effectively increases the gas exhausting rate and enhances safety by ensuring the pressure relief mechanism is actuated in a timely manner, reducing the risk of explosion and fire by providing a more efficient path for gas release while maintaining a high energy density.
Implementation Method 1
a duct, configured to guide gas between the second side plate and the support member into the pressure relief mechanism
Implementation Method 2
the pressure relief mechanism is actuated to release a pressure when the pressure reaches a threshold
Data Source
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AI summary
Embodiments of this application provide a battery cell, a method and system for manufacturing same, a battery, and an electrical device. The battery cell according to embodiments of this application includes: an electrode assembly; a shell assembly, configured to accommodate the electrode assembly and including a first side plate and a second side plate, where the first side plate and the second side plate are located on two sides of the electrode assembly along a first direction respectively; a pressure relief mechanism, disposed on the first side plate; and a support member, disposed between the electrode assembly and the first side plate, and configured to support the electrode assembly. A duct is provided on the support member. The duct is configured to guide gas between the second side plate and the support member into the pressure relief mechanism, so that the pressure relief mechanism is actuated to release a pressure when the pressure reaches a threshold. A first recess is formed on a side that is of the second side plate and that faces the electrode assembly, and the first recess is configured to accommodate at least a part of the electrode assembly. This application can increase the gas exhausting rate during thermal runaway of the battery cell on the basis of ensuring a relatively high capacity of the battery cell, thereby improving safety of the battery cell.