Cylindrical Battery Case Vent Structure for Pressure-Triggered Gas Release
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Solution Overview
Problem
Cylindrical secondary batteries face safety risks due to gas generation and temperature rise, with existing safety devices failing to adequately address these issues.
Innovation Solution
A case for secondary batteries featuring a gas discharge device with recessed areas and adhesion parts that form a passage for gas release when pressure exceeds a threshold, allowing rapid discharge of gas and reducing internal pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If safety devices such as CID filter and safety vent are provided in cylindrical secondary batteries, then safety is improved, but gas discharge speed is insufficient and safety is not completely guaranteed
Solution Approach 1:
The gas discharge device transitions from a static structure to a dynamic one where the adhesion part automatically separates under pressure. The recess part and adhesion part remain adhered during normal operation, maintaining structural integrity, but automatically separate when internal pressure exceeds the adhesion force, enabling rapid gas discharge without requiring complex active control mechanisms.
Solution Approach 2:
The invention changes the state of the gas discharge passage from closed to open by altering the adhesion parameter. Under normal conditions, the adhesion part maintains strong adhesion to keep the passage closed. When pressure increases, the adhesion parameter changes as the adhesive force is overcome, automatically opening the passage for gas discharge.
2Speed
If a gas discharge device with recess part and adhesion part is used, then gas discharge speed is improved, but device complexity increases
Solution Approach 1:
The gas discharge device is integrally formed with the battery can, merging the discharge mechanism into the existing structural component. The recess part and adhesion part are formed as integral features of the battery can itself, eliminating the need for separate discrete components and reducing overall device complexity while maintaining the rapid discharge capability.
Solution Approach 2:
The adhesion part automatically separates and reattaches based on pressure conditions without external control. The system serves itself by using the pressure differential to control the adhesion state, eliminating the need for sensors, actuators, or control systems that would increase complexity.
3Productivity
If adhesion part is spaced from inner surface of body part, then gas discharge passage is effectively formed, but manufacturing precision requirements increase
Solution Approach 1:
The adhesion part is spaced from the inner surface only at specific locations where gas discharge is needed, while maintaining adhesion in other areas. This local spacing creates effective discharge passages without requiring precise spacing across the entire surface, reducing manufacturing precision requirements to only critical discharge zones.
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 gas to enhance safety by preventing explosion and ignition, ensuring rapid pressure reduction.
Implementation Method 1
a first adhesion part formed by allowing at least a portion of the first recess area and at least a portion of the second recess area to adhere to each other
Implementation Method 2
when the pressure of the empty space in the body part exceeds the predetermined value, the passage is formed through the cutoff area of the recess part
Data Source
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AI summary
Disclosed are a case for secondary battery, a secondary battery including the case for secondary battery, and a method for manufacturing the case for secondary battery. According to the present invention, a gas discharge device formed in the case for secondary battery may include a recess part, wherein a cut cutoff area may be formed in the recess part, and a passage through which a gas is discharged through the cutoff area of the recess part when a pressure of the empty space in the body part exceeds a predetermined value may be formed.