Pouch Cell Venting Assembly With Ball-Spring Pressure Relief
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Solution Overview
Problem
Pouch-type secondary batteries lack effective gas discharge mechanisms, leading to potential explosions due to increased internal pressure from gas generation, which can cause component damage, early protection circuit activation, and deformation, unlike can-type batteries that have safety vents.
Innovation Solution
A venting device is inserted into the sealing part of the pouch, comprising a housing, a sheet with a passage for gas discharge, a metal plate spring that opens and closes based on internal pressure, and a hemispherical ball that interacts with the plate spring to control passage opening, minimizing plate spring bending and pressure deviation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a protection member is not provided in pouch type secondary batteries, then the device complexity is reduced and manufacturing is easier, but safety reliability deteriorates due to potential explosions from internal pressure increase
Solution Approach 1:
The venting device is designed to automatically activate based on internal pressure conditions without requiring external control systems. The plate spring and ball mechanism self-regulate the passage opening and closing based on pressure differential, providing safety through self-service operation.
Solution Approach 2:
The invention utilizes pressure as a changing parameter to trigger the safety mechanism. When internal pressure exceeds a threshold, the pressure differential causes the ball to move and open the passage, automatically relieving pressure without complex control systems.
2Device complexity
If a simple venting structure is used, then device complexity is reduced, but manufacturing precision deteriorates due to plate spring bending and pressure deviation
Solution Approach 1:
The ball component with its spherical geometry provides stable, consistent contact with the passage opening. The curved surface ensures uniform force distribution and predictable opening pressure, reducing manufacturing precision requirements while maintaining consistent operation.
Solution Approach 2:
The plate spring is pre-loaded to a specific curvature and tension during manufacturing to establish a predetermined opening pressure threshold. This preliminary action ensures that the venting device opens at a consistent pressure regardless of minor manufacturing variations.
3Ease of operation
If the plate spring is allowed to bend freely, then the device complexity is reduced and operation is simpler, but manufacturing precision deteriorates due to inconsistent opening pressure
Solution Approach 1:
The spherical ball provides a consistent geometric reference that guides the plate spring's bending motion. This curvature ensures that the spring deforms in a predictable manner, maintaining opening pressure consistency while allowing simple, free-bending operation.
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 venting device effectively discharges gases from the pouch, reducing plate spring bending and pressure deviation, thereby enhancing safety by minimizing the risk of explosion and maintaining consistent opening pressure.
Implementation Method 1
a plate spring which opens and closes the passage according to an internal pressure of the pouch and is made of made of a metal having elasticity
Implementation Method 2
a ball disposed between the sheet and the plate spring so as to contact or be spaced apart from the sheet at an outlet-side of the passage, thereby closing or opening the passage
Data Source
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AI summary
A venting device, which is inserted into a sealing part of a pouch of a secondary battery, according to an embodiment of the present invention for solving the above problem includes: a housing inserted between both surfaces of the sealing part so as to be sealed together with the sealing part; a sheet which is formed in the housing and through which a passage, through which the inside and outside of the pouch communicate with each other, passes; a plate spring which opens and closes the passage according to an internal pressure of the pouch and is made of made of a metal having elasticity; and a ball disposed between the sheet and the plate spring so as to contact or be spaced apart from the sheet at an outlet-side of the passage, thereby opening and closing the passage, wherein the ball has a hemispherical shape to be attached to an inner surface of the plate spring.