Pouch Secondary Battery Venting With Dual Gas Pockets
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Solution Overview
Problem
Conventional pouch type batteries experience reduced performance and life due to gas generation, which can lead to venting, leakage of electrolyte solution, and structural damage when the generated gas exceeds the pouch's accommodation limit.
Innovation Solution
A secondary battery design featuring dual gas pockets with separate exhaust ports that open at different pressures, equipped with a gas sensor and air pressure sensor, allowing for efficient gas collection and controlled exhaust, preventing direct air contact and structural rupture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas is generated inside the pouch during charging and discharging, then battery operation is enabled, but gas accumulation causes reduced battery performance, volume changes, and potential venting
Solution Approach 1:
The battery case is divided into multiple functional regions: a gas collection space separated from the electrode assembly, and a venting space for gas discharge. This segmentation allows gas to be collected in a dedicated space during normal operation, preventing gas accumulation in the electrode assembly area, while providing a controlled path for gas venting when pressure exceeds thresholds, thus maintaining both operational functionality and structural reliability
Solution Approach 2:
A valve mechanism acts as an intermediary between the gas collection space and the external environment. The valve remains closed during normal operation to maintain battery sealing and prevent moisture ingress, but opens automatically when gas pressure exceeds a predetermined threshold, providing controlled gas release while protecting the battery structure from damage
2Quantity of substance
If the pouch accommodates more gas, then gas generation during operation is tolerated, but the pouch structure becomes weaker and more prone to rupture and leakage
Solution Approach 1:
The battery case is divided into multiple functional regions: a gas collection space separated from the electrode assembly, and a venting space for gas discharge. This segmentation allows gas to be collected in a dedicated space during normal operation, preventing gas accumulation in the electrode assembly area, while providing a controlled path for gas venting when pressure exceeds thresholds, thus maintaining both operational functionality and structural reliability
Solution Approach 2:
The valve mechanism is pre-configured with a predetermined opening pressure threshold that acts as a safety buffer. Before gas pressure can reach levels that would cause pouch rupture or structural damage, the valve opens to release excess gas, thereby cushioning the system against pressure-related structural failures
3Stress or pressure
If venting is implemented to release gas, then gas pressure is reduced, but electrolyte solution leaks and the battery reaches end of life
Solution Approach 1:
A valve mechanism acts as an intermediary between the gas collection space and the external environment. The valve remains closed during normal operation to maintain battery sealing and prevent moisture ingress, but opens automatically when gas pressure exceeds a predetermined threshold, providing controlled gas release while protecting the battery structure from damage
Solution Approach 2:
The valve mechanism utilizes a flexible membrane or diaphragm that responds to pressure differential. The flexible structure allows the valve to open only when gas pressure exceeds the predetermined threshold, providing precise control over when venting occurs and preventing premature opening that would cause electrolyte leakage while still allowing necessary gas release
Data Source
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AI summary
The present invention relates to a secondary battery. The secondary battery according to the present invention comprises an electrode assembly wherein electrodes and separators are alternatingly stacked, and a battery case in which the electrode assembly is accommodated, where the battery case comprises a first gas pocket on which a first collection space for collecting gases in the battery case is formed, and on which is provided a first exhaust port from which gases in the first collection space are exhausted, and a second gas pocket on which a second collection space for collecting gases exhausted from the first exhaust port is formed, and on which is provided a second exhaust port for outward exhaust of gas in the second collection space.