Battery Pack Sealing Geometry for High-Temperature Gas Management
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Solution Overview
Problem
The existing battery pack designs suffer from deterioration of the sealing material between the upper and lower cases due to high-temperature gas discharged from battery cells, which increases internal pressure and compromises the sealing capabilities.
Innovation Solution
A battery pack configuration featuring a specific geometry of the upper and lower cases with a constricting portion and a pressure release valve, where the constricting portion's height is lower than the facing and non-facing portions, directing high-temperature gas away from the sealing material and allowing pressure relief.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the housing case is sealed with sealing material between the upper case and lower case, then the sealing capability is improved, but the sealing material deteriorates when high-temperature gas contacts it
Solution Approach 1:
The upper case is segmented into multiple functional portions: a facing portion that faces the battery stack, a non-facing portion that does not face the battery stack, and a constricting portion connecting them. This segmentation directs high-temperature gas away from the sealing material while maintaining sealing capability.
Solution Approach 2:
The constricting portion acts as an intermediary structure between the facing and non-facing portions. Its lower height creates a barrier that intercepts high-temperature gas discharged from the battery stack, preventing direct contact with the sealing material disposed between the flange portions.
2Strength
If the internal space is sealed to maintain structure, then structural integrity is improved, but pressure buildup occurs when gas is discharged
Solution Approach 1:
A pressure release valve is provided in the bottom portion of the upper case to extract and release excess pressure from the internal space. This allows the housing case to maintain structural integrity while preventing dangerous pressure buildup from discharged high-temperature gas.
3Ease of manufacture
If the upper case has a uniform height structure, then manufacturing is simplified, but gas flow direction cannot be controlled
Solution Approach 1:
The upper case employs an asymmetric height structure with a constricting portion that has a lower height than the facing and non-facing portions. This asymmetric design creates a directional barrier that controls gas flow path, directing high-temperature gas away from the sealing material while remaining manufacturable.
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
This configuration effectively suppresses the deterioration of the sealing material by managing high-temperature gas discharge and maintaining sealing integrity, even under increased internal pressure.
Implementation Method 1
a constricting portion provided at a position between the facing portion and the non-facing portion, a height position of the constricting portion in the third direction being lower than a height position of the facing portion and a height position of the non-facing portion in the third direction
Implementation Method 2
a pressure release valve provided on the bottom portion, and the pressure release valve may be configured to open when a pressure in the internal space exceeds a predetermined value
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A battery pack (100) includes a battery stack (2), an upper case (10) including a first main body portion (10M) and a first flange portion (15a), a lower case (20) including a second main body portion (20M) and a second flange portion (25a), and sealing material (26) included in a sealing structure between the first flange portion (15a) and the second flange portion (25a). The first main body portion (10M) includes a facing portion (11) that faces the battery stack (2) in a third direction (DR3), a non-facing portion (13) provided at a position that is on a side of the facing portion (11) with respect to a position of the first flange portion (15a) in the first direction (DR1) and that does not face the battery stack (2), and a constricting portion (12) that is provided at a position between the facing portion (11) and the non-facing portion (13) in the first direction (DR1), and of which a height position is lower than height positions of the facing portion (11) and the non-facing portion (13).