Battery Pack Venting Structure to Block Oxygen Backflow
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Solution Overview
Problem
Existing battery packs face increased damage and fire risk due to rapid venting pressure changes and oxygen introduction during thermal events, leading to negative pressure and ignition of high-temperature gases and sparks.
Innovation Solution
A battery pack structure that includes an oxygen introduction preventing member and pack cover configuration to control the discharge of venting gas, minimizing negative pressure and oxygen introduction by guiding venting gas flow and using pressure-sensitive valves to manage fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If venting gas is discharged rapidly to reduce internal pressure during thermal event, then pressure relief is improved, but negative pressure generation increases causing oxygen introduction
Solution Approach 1:
A venting gas discharge control member is introduced as an intermediary component between the venting gas and the external environment. This control member regulates the discharge process to prevent rapid pressure reduction that would cause negative pressure and oxygen introduction, while still allowing effective pressure relief during thermal events.
Solution Approach 2:
The discharge characteristics of venting gas are controlled by changing parameters such as discharge area, discharge timing, and discharge velocity. The venting gas discharge control member adjusts these parameters to maintain pressure within a safe range, preventing both excessive pressure buildup and rapid pressure reduction that would create negative pressure.
2Quantity of substance
If number of lithium secondary batteries is increased to achieve high capacity, then battery capacity is improved, but fire damage risk increases
Solution Approach 1:
The battery pack is divided into multiple battery modules, each with its own venting gas discharge control member. This segmentation allows localized control of venting gas discharge for each module, preventing fire propagation to adjacent modules while maintaining high overall battery capacity through the increased number of batteries.
3Stress or pressure
If venting pressure decreases rapidly after thermal event, then pressure relief is improved, but negative pressure acts inward introducing oxygen
Solution Approach 1:
The venting gas discharge control member incorporates feedback mechanisms that monitor internal pressure conditions and adjust discharge characteristics accordingly. When pressure decreases and approaches levels that would create negative pressure, the control member automatically adjusts to prevent oxygen introduction, maintaining reliable fire prevention.
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 solution effectively manages venting gas discharge to prevent explosions and fires by maintaining stable pressure and reducing oxygen introduction, enhancing safety in battery packs.
Implementation Method 1
using pressure-sensitive valves to manage fluid flow
Implementation Method 2
venting gas, generated during a thermal event, may be discharged at an appropriate speed despite high initial venting pressure
Data Source
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AI summary
A battery pack according to an embodiment includes a module assembly including a plurality of battery modules each including, on a side, a module opening through which venting gas is discharged, a pack cover facing the module opening and configured to cover the side of the module assembly, and an oxygen introduction preventing member located in a space formed between the module assembly and the pack cover and configured to prevent oxygen from being reversely introduced after venting gas is discharged in an extension direction of the space.