Battery Pack Inner Case Venting for Blowout Gas Pressure Reduction
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Solution Overview
Problem
Existing power supply devices with secondary battery cells face challenges in safely managing and reducing the pressure and temperature of large amounts of blowout substances, such as gas, discharged during unsafe events, which can lead to thermal damages and flames.
Innovation Solution
A power supply device with an inner case having a stacked structure of first and second plates forming a tubular exhaust duct, where the first plate has groove-shaped recesses with a cut end as the first opening and the second plate forms the second opening, allowing blowout substances to be discharged through the duct, reducing pressure and temperature before exiting the outer case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of battery cells is increased to satisfy higher output and capacity demand, then the power supply capacity is improved, but the amount of blowout substances discharged during abnormality increases, making it difficult to reduce pressure and temperature efficiently
Solution Approach 1:
The exhaust path is segmented into multiple sections: the exhaust passage in the upper case, the exhaust passage in the lower case, and the discharge passage. This segmentation creates a multi-stage pressure reduction system where blowout substances progressively lose pressure as they move through each section, enabling effective handling of large volumes of discharged substances even in high-capacity battery packs
Solution Approach 2:
The exhaust duct is nested within the stacked structure of the upper and lower cases. The exhaust passage in the upper case connects to the exhaust passage in the lower case, which in turn connects to the discharge passage. This nested arrangement allows blowout substances to traverse through multiple confined spaces in sequence, maximizing pressure reduction while maintaining a compact overall structure
2Reliability
If a labyrinth-like exhaust path is used to reduce pressure and temperature of blowout substances, then safety is improved by preventing flame discharge, but the structure becomes complex and may not be sufficient for large amounts of blowout substances from high-capacity devices
Solution Approach 1:
The exhaust system is divided into distinct functional segments: the exhaust passage in the upper case for initial pressure reduction, the exhaust passage in the lower case for further pressure reduction, and the discharge passage for final controlled release. This segmentation achieves effective flame prevention through multiple pressure reduction stages while maintaining relatively simple individual components
Solution Approach 2:
The exhaust passages in both the upper and lower cases are merged into a continuous flow path. The bottom of the exhaust passage in the upper case communicates with the exhaust passage in the lower case, creating an integrated multi-stage pressure reduction system that combines the safety benefits of complex labyrinthine paths with simpler individual case structures
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 structure effectively discharges large amounts of gas and foreign substances safely outside the outer case, preventing ignition by reducing temperature and pressure, and allowing foreign substances to be smoothly expelled, thus enhancing safety.
Implementation Method 1
The inner case includes a first plate and a second plate that constitute a side wall of the inner case. The first plate and the second plate extend in an extending direction of the inner case, and form a stacked part of the side wall in which the first plate and the second plate are partially stacked
Implementation Method 2
The exhaust duct communicates with an inside and an outside of the inner case via the first opening and the second opening, allowing blowout substances to be discharged through the duct, reducing pressure and temperature before exiting the outer case
Data Source
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AI summary
A power supply device includes secondary battery cells, an inner case accommodating the secondary battery cells therein, and an outer case covering the inner case. The inner case includes first and second plates constituting a side wall of the inner case. The first and second plates form a stacked part of the side wall in which the first and second plates are stacked on each other. The first plate has groove-shaped recesses in a surface thereof facing the second plate. Each of the groove-shaped recesses has a cut end at one end of the each of the groove-shaped recesses cut in a direction intersecting an extending direction of the groove-shaped recesses, the cut end constituting a first opening. The second plate forms a tubular exhaust duct in a part of the second plate stacked on the first plate by closing the one end of the each of the groove-shaped recesses where the first opening of the each of the groove-shaped recesses is formed. The second plate constitutes a second opening at another end of the each of the groove-shaped recesses opened and unclosed by the second plate. The exhaust duct communicates with an inside and an outside of the inner case via the first opening and the second opening.