Secondary Battery Top Cover Valve Sleeve for Pressure-Triggered Venting
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Solution Overview
Problem
Secondary batteries, such as lithium-ion batteries, face increased internal pressure due to gas production, leading to bulging and performance degradation, and existing vents are disposable and ineffective in managing slow gas production, posing safety risks.
Innovation Solution
A top cover assembly with a deformable valve sleeve and valve part, where the valve sleeve forms a gas exhaust passage under pressure, allowing controlled gas release while maintaining tight coupling at lower pressures, and a venting system that includes a valve cover and accommodation groove to manage gas exhaust without deforming the battery or vent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vent is used to exhaust gas from the secondary battery, then gas pressure can be reduced, but the vent is disposable and cannot handle slow gas production over time
Solution Approach 1:
The valve sleeve is designed to dynamically change its state between tight coupling (sealed) and deformation (exhausting) based on internal pressure conditions. This dynamic response allows the same structure to function continuously for both slow gas production management and rapid pressure relief, eliminating the need for disposable vents.
Solution Approach 2:
The valve sleeve automatically responds to pressure changes without external control. When internal pressure increases, the gas force causes the valve sleeve to deform and form an exhaust passage. When pressure normalizes, the valve sleeve returns to tight coupling. This self-regulating mechanism ensures continuous operation without replacement.
2Stress or pressure
If gas is exhausted through a vent, then internal pressure is reduced, but the battery case may bulge and deform due to pressure changes
Solution Approach 1:
The valve sleeve's deformation state changes based on pressure parameters. At normal pressure, it maintains tight coupling to prevent gas escape. When pressure exceeds the deformation threshold, it automatically forms an exhaust passage to release gas, thereby controlling internal pressure within safe limits and preventing case bulging.
3Reliability
If the valve sleeve is always in tight coupling with the valve part, then sealing is maintained, but gas cannot be exhausted when pressure increases
Solution Approach 1:
The valve sleeve transitions between two states: tight coupling for sealing during normal operation, and deformation for gas exhaust when pressure increases. This dynamic behavior allows the system to maintain both sealing performance and pressure relief capability using the same component.
Solution Approach 2:
The sealing state of the valve sleeve is controlled by pressure parameters. When internal pressure is normal, the valve sleeve maintains tight coupling with the valve part for sealing. When pressure exceeds the deformation threshold, the valve sleeve deforms to create an exhaust passage, automatically switching between sealing and venting functions.
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 reduces internal pressure through controlled gas release, enhancing safety by preventing excessive pressure buildup and ensuring the battery's deformable components operate within a preset pressure range without failure.
Implementation Method 1
the valve sleeve is configured to deform under a force applied by gas exhausted from the at least one gas exhaust hole so as to form the gas exhaust passage between the valve sleeve and the valve part
Implementation Method 2
the valve sleeve is configured to be in tight coupling with the valve part when the force applied by the gas is smaller than a force under which the valve sleeve begins to deform
Data Source
Figure 1~2
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AI summary
The present disclosure provides a secondary battery and a top cover assembly thereof. The top cover assembly includes: a top cover plate and a valve sleeve. The top cover plate includes an accommodation groove and a valve part protruding upward from a bottom wall of the accommodation groove, and the valve part is provided with at least one gas exhaust hole that communicates with an interior of the secondary battery. The valve sleeve is located in the accommodation groove and covers the valve part, a gas exhaust passage that communicates with outside is disposed between the valve sleeve and the valve part, and the gas exhaust passage communicates with the at least one gas exhaust hole.