Battery Module Coolant Venting to Stop Thermal Propagation
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Solution Overview
Problem
Existing battery modules fail to effectively stop the spread of fire to other battery cells due to the time delay in water contact during fire extinguishing and the rapid thermal propagation caused by high temperature gas in water-cooled modules.
Innovation Solution
A battery module design featuring a module case with an upper and lower plate, each with a channel for coolant flow and a vent hole for gas exit, where the sealing caps are made of thermomeltable materials to quickly feed coolant to the affected cell and force out high temperature gas, preventing thermal propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If water-cooled battery modules use an air-tight structure to improve cooling efficiency, then cooling performance is improved, but high temperature gas cannot be smoothly vented and thermal propagation occurs faster
Solution Approach 1:
The air-tight structure is segmented by introducing a vent hole that allows high temperature gas to escape. The sealing cap can be opened to create this venting pathway, dividing the previously closed system into a controlled venting system that maintains cooling efficiency while enabling gas discharge to prevent thermal propagation.
Solution Approach 2:
The sealing cap is pre-configured with a melting spot that will automatically open the vent hole when exposed to high temperature. This preliminary arrangement ensures that when thermal runaway occurs, the gas venting function activates automatically without requiring external control, thus preventing thermal propagation while maintaining the air-tight structure's cooling efficiency.
2Reliability
If a fire extinguishing system uses a water valve to feed water into the battery pack, then fire suppression capability is improved, but there is a time delay before water contacts the affected battery cell
Solution Approach 1:
The coolant channel is pre-filled with coolant and positioned in direct thermal contact with the battery cell. The sealing cap with a melting spot is pre-configured to automatically open when exposed to high temperature. This preliminary arrangement eliminates the time delay associated with valve activation and water transport, as the coolant is already in position to immediately suppress fire when the sealing cap melts.
Solution Approach 2:
The system uses the heat from the fire itself to trigger the opening of the sealing cap through the melting spot mechanism. This self-activating feature eliminates the need for external detection and control systems, ensuring immediate response time while maintaining reliable fire suppression capability.
3Quantity of substance
If battery modules densely pack secondary batteries to improve energy density, then energy density is improved, but thermal runaway propagation to adjacent cells becomes more prone
Solution Approach 1:
The module case is designed with individual coolant channels for each battery cell, creating segmented cooling zones. The sealing cap with vent hole provides individual protection for each cell. This segmentation allows localized fire suppression and prevents thermal runaway from propagating to adjacent cells, enabling dense packing while maintaining safety.
Solution Approach 2:
The coolant channel acts as an intermediary between the battery cell and the external environment, providing direct thermal contact for heat removal. The sealing cap serves as an intermediary that controls the interface between the cell and the coolant, automatically opening to allow coolant injection when thermal runaway occurs, thus preventing propagation to adjacent cells in densely packed configurations.
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 enables immediate cooling of the affected battery cell and effective venting of high temperature gas, thereby quickly stopping the fire spread and improving the energy density and safety of the battery module.
Implementation Method 1
the upper plate and the lower plate include a melting spot which melts when heated in a first plate in contact with the plurality of battery cells
Implementation Method 2
each having a channel in which a coolant flows
Data Source
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AI summary
According to the present disclosure, a battery module includes a plurality of battery cells; and a module case accommodating the plurality of battery cells, wherein the module case include an upper plate positioned on the plurality of battery cells and a lower plate positioned below the plurality of battery cells, each having a channel in which a coolant flows, the upper plate and the lower plate include a melting spot which melts when heated in a first plate in contact with the plurality of battery cells, and the upper plate includes a vent hole and a first sealing cap in a second plate which faces the first plate, the vent hole through which gas is forced out, and the first sealing cap configured to seal the vent hole and made of a thermomeltable material.