Thermal Protection Device for Lithium-Ion Battery Fire Suppression
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Solution Overview
Problem
Current thermal protection solutions for lithium-ion batteries during storage and transport are inadequate as they can lead to accidental fire spread due to structural defects or mechanical contact issues, and existing containment methods fail to effectively manage thermal runaway, risking the entire cargo in case of self-heating.
Innovation Solution
A thermal protection device with a heat-resistant peripheral envelope and internal partitioning structure forming reservoirs for a flame-retardant fluid, featuring a thermosensitive and non-flammable membrane that selectively releases the fluid at a predetermined temperature to control overheating or fire, maintaining the membrane's distance from the object to prevent accidental rupture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a flexible bag structure is used to contain the flame-retardant fluid, then the device can adapt to the object shape, but the mechanical contact required to break the bag can cause accidental opening and premature liquid release
Solution Approach 1:
The patent uses a rigid envelope with a thermosensitive membrane instead of a flexible bag. The membrane is less rigid than the envelope and can be locally ruptured at a predetermined temperature, providing both structural integrity and responsive activation without mechanical contact issues.
Solution Approach 2:
The patent replaces the mechanical contact-based activation (breaking a flexible bag) with a thermal-based activation (thermosensitive membrane rupture). This substitution eliminates the reliability issue of accidental mechanical opening while maintaining the ability to release fluid in response to thermal runaway.
2Speed
If the membrane is placed close to the object for direct protection, then the response time is reduced, but the risk of accidental rupture due to mechanical contact increases
Solution Approach 1:
The thermosensitive membrane is designed to be less rigid than the envelope, allowing it to be positioned close to the object for rapid thermal response while the rigid envelope provides structural support that prevents accidental mechanical rupture during normal handling.
Solution Approach 2:
The membrane's thermal sensitivity parameter is optimized to rupture at a predetermined temperature associated with thermal runaway. This ensures the membrane remains intact under normal mechanical conditions (maintaining reliability) while responding quickly when the temperature parameter reaches the critical threshold (maintaining speed).
3Reliability
If a rigid envelope is used to maintain structural integrity, then accidental rupture is prevented, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent combines a rigid envelope with a less rigid thermosensitive membrane, creating a hierarchical structure where the rigid envelope provides overall structural integrity while the softer membrane provides the responsive activation function. This division of functional requirements simplifies the design compared to making the entire structure rigid.
Solution Approach 2:
The device uses composite construction with the rigid envelope and the thermosensitive membrane having different rigidity properties. This composite approach allows each layer to perform its specific function optimally - the rigid envelope for structural integrity and the thermosensitive membrane for controlled rupture - without significantly increasing overall manufacturing complexity.
4Object-affected harmful factors
If containment solutions are used to confine fire, then the spread to other batteries is prevented, but the flame remains active and can spread if the containment presents an unforeseen defect
Solution Approach 1:
The device activates before thermal runaway fully develops by detecting the predetermined temperature threshold and releasing the flame-retardant fluid proactively. This preliminary action prevents the fire from becoming active in the first place, rather than relying on containment to stop an already-established fire that could spread if the containment fails.
Solution Approach 2:
The device converts the thermal energy that would cause harmful fire into a beneficial trigger signal. The heat from thermal runaway is detected by the thermosensitive membrane, which responds by rupturing and releasing the flame-retardant fluid to counteract the thermal runaway, thus converting the harmful thermal effect into a useful activation signal.
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 device effectively limits or stops thermal runaway by releasing the flame-retardant fluid directly to the critical zone, preventing widespread fire and preserving the storage environment, while maintaining structural integrity and avoiding accidental fluid release.
Implementation Method 1
these batteries are classified as hazardous materials due to their ability to self-heat when they are subjected to certain environmental constraints or present manufacturing defects that are often undetectable. This self-heating is likely to produce a thermal runaway that can exceed 1000° C with an outbreak of fire
Implementation Method 2
at least one thermosensitive and non-flammable membrane which is less rigid than said envelope to which it is fixed by forming a bottom for the reservoirs, said at least one membrane being capable of being locally ruptured at a predetermined temperature generated by the critical zone so as to release the fluid from at least one of the reservoirs selectively towards and in contact with the critical zone to limit or stop the overheating or the start of a fire
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a thermal protection device against unwanted heating or fire in a critical area of at least one object within a container, a container housing this device, and a method for preventing heating or fire. The device (6) is adapted to be fitted inside the container (1) by surmounting at least one object (3) housed therein, the device being delimited by an external wall adapted to contain a fire-retardant fluid (7).According to the invention, said outer wall comprises: - a peripheral heat-resistant envelope (8) provided with an internal partition structure (9) forming reservoirs (10) for the fluid, and - at least one heat-sensitive and non-flammable membrane (11) which is less rigid than the envelope to which it is attached, forming a bottom (10a) for the reservoirs, the membrane being capable of being locally ruptured at a predetermined temperature generated by the critical zone so as to release the fluid from at least one of the reservoirs selectively towards and in contact with the critical zone in order to limit or stop heating or the start of fire.