Pouch Battery Valve Structure for Pressure-Triggered Gas Venting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pouch-type secondary batteries experience swelling due to gas generation during charging/discharging, which deforms the pouch and poses a risk of explosion, necessitating a mechanism to safely discharge the gas.
Innovation Solution
A secondary battery with a valve system comprising an inner and outer tube, filled with adhesive, where the inner tube deforms to create a gap for gas discharge when pressure increases, using gaseous nitrogen to protect the inner tube and adjust pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pouch-type secondary battery is sealed to maintain integrity, then the pouch structure is protected, but gas generated during charging/discharging causes swelling and deformation
Solution Approach 1:
A valve structure is introduced as an intermediary component between the sealed pouch interior and exterior. The valve includes an inner tube with adhesive and an outer tube that acts as a mediator to control gas release. When internal pressure increases due to gas generation, the adhesive in the inner tube deforms and creates a gap, allowing gas to escape through the valve to the outside, thus preventing pouch swelling while maintaining sealed integrity during normal operation.
Solution Approach 2:
The valve mechanism utilizes parameter changes in the adhesive material's physical state. Under normal pressure conditions, the adhesive maintains a sealed state. When internal pressure increases beyond a threshold, the adhesive deforms and changes its physical configuration, creating a gap that transitions the valve from a closed to an open state, enabling controlled gas discharge.
2Object-affected harmful factors
If a valve is added to discharge gas, then swelling is prevented, but the device complexity increases
Solution Approach 1:
The valve structure is designed to operate autonomously without external control mechanisms. The inner tube contains adhesive that automatically responds to internal pressure changes. When gas generation increases internal pressure, the adhesive self-deforms under the pressure differential, opening the valve pathway. When pressure normalizes, the adhesive returns to its original state, closing the valve. This self-service mechanism eliminates the need for complex control systems, sensors, or actuators.
Solution Approach 2:
The complex active control system is extracted and replaced with a passive, pressure-responsive adhesive mechanism. The valve extracts only the essential function of pressure-responsive opening/closing, removing unnecessary complexity from the battery system while maintaining effective gas discharge capability.
3Ease of operation
If the inner tube is made flexible to create gaps for gas discharge, then gas venting is enabled, but the inner tube becomes vulnerable to external impacts
Solution Approach 1:
The inner tube is nested within the outer tube, creating a protective hierarchical structure. The flexible inner tube maintains its gas discharge functionality through adhesive deformation, while the rigid outer tube serves as a protective shell that absorbs and distributes external impact forces. This nested configuration allows the inner flexible component to perform its function while being shielded by the outer protective structure.
Solution Approach 2:
The outer tube provides beforehand cushioning protection for the inner tube against external impacts. By positioning the rigid outer tube surrounding the flexible inner tube before any impact occurs, the structure pre-establishes a protective barrier that cushions the inner tube from mechanical damage while allowing the inner tube to remain flexible enough for gas discharge 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
Effectively prevents swelling by allowing controlled gas discharge, protecting the inner tube from external impacts and maintaining the pouch's integrity.
Implementation Method 1
the inner tube is deformed in a direction in which an inner diameter of the inner tube is expanded when swelling is generated in the pouch to increase in pressure
Implementation Method 2
Gaseous nitrogen may be injected into the chamber formed between the inner tube and the outer tube to protect the inner tube
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention provides a secondary battery provided with a pouch, in which a sealing potion formed on an edge thereof is sealed when an electrode assembly and an electrolyte are enclosed, the secondary battery comprising: a valve which is mounted on a sealing portion so that one end thereof is disposed inside the pouch, and the other end thereof is disposed outside the pouch and discharges a gas generated inside the pouch to the outside, wherein the valve comprises an inner tube filled with an adhesive and made of a material that is deformed when swelling occurs, and when the swelling occurs to increase in pressure inside the pouch, a gap is generated in a portion that is filled with the adhesive, and the gas within the pouch is discharged to the outside though the gap. In the present invention having the above configuration, the adhesive may be filled in the inner tube to prevent the electrolyte from leaking and prevent external moisture from being permeated, but only when the pressure inside the pouch increases, the gap may be generated to discharge the gas, thereby efficiently preventing the swelling from occurring.