Battery Pack Ventilation for Thermal Runaway Gas Dilution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric vehicles with lithium-ion or lithium-metal battery packs face challenges in preventing the ignition of flammable gases released during thermal runaway, which can lead to fires.
Innovation Solution
A vehicle is equipped with a battery pack having a housing with vents for gas discharge, a thermal management system that cools and dilutes battery gases using external air drawn by a fan, and a controller that opens valves to allow air to enter the battery pack and cool the cells when elevated temperatures are detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If battery gases are allowed to vent directly to the atmosphere, then gas discharge is achieved, but the flammable gases may be ignited by hot battery temperatures resulting in fire
Solution Approach 1:
The patent introduces an intermediary system consisting of a vent channel, cooling passage, and atmosphere communication passage that mediates between the battery pack and the atmosphere. This intermediary structure allows thermal runaway gases to be discharged while simultaneously cooling them with ambient air, preventing ignition without requiring complex active control systems.
Solution Approach 2:
The patent converts the harmful hot thermal runaway gases into a beneficial cooling process by allowing ambient air to flow through the vent channel and cool the gases before they exit to the atmosphere. The harmful hot gases become the medium through which cooling occurs, transforming the hazard into a protective mechanism.
2Temperature
If a complex thermal management system with active cooling is implemented, then battery cell cooling is improved, but device complexity increases
Solution Approach 1:
The patent merges the gas venting function with the thermal management function into a single integrated structure. The vent channel serves dual purposes: discharging thermal runaway gases and providing a pathway for ambient air to cool the battery cells. This consolidation eliminates the need for separate active cooling systems while maintaining effective temperature control.
Solution Approach 2:
The system uses the ambient atmosphere itself as the cooling medium, eliminating the need for external cooling resources. The natural flow of air through the vent channel provides passive cooling to the battery cells during thermal runaway, making the system self-regulating without requiring active control mechanisms.
3Temperature
If air is drawn into the battery pack to cool battery cells, then cooling effectiveness is improved, but the system requires additional components increasing complexity
Solution Approach 1:
The system dynamically adapts its operation based on thermal conditions. During normal operation, the vent channel remains closed or minimally open. During thermal runaway, the channel automatically opens to allow ambient air to flow through and cool the battery cells, providing dynamic response without complex sensors or control systems.
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 system effectively cools and dilutes battery gases during thermal runaway, reducing the risk of ignition and minimizing the danger to occupants and vehicle components.
Implementation Method 1
an air induction device for drawing air from the atmosphere located external to the battery pack into the inlet pipe
Implementation Method 2
cool each of the battery cells and dilute the battery gases generated by the plurality of battery cells
Implementation Method 3
a fan, the plurality of outlet pipes, and a controller... instruct the air induction device to begin drawing the air into the inlet pipe
Implementation Method 4
dilute the battery gases generated by the plurality of battery cells before a mixture of the air and battery gases exit the battery pack
Data Source
AI summary
A battery thermal management system including an air induction device for drawing air to a battery pack, a controller, a valve that opens to permit the air to enter the battery pack, and a temperature sensor for generating signals indicative of a temperature within the battery pack. Upon receipt of a signal from the temperature sensor that is indicative of the temperature within the housing being above a predetermined threshold, the controller is configured to instruct the air induction device to begin drawing the air, and instruct the valve to open to permit the air to enter the battery pack and cool each of the battery cells and dilute the battery gases generated by the plurality of battery cells.