Battery Pack Melting Bolt Venting for Thermal Runaway Containment
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Solution Overview
Problem
Existing battery packs are vulnerable to thermal runaway, leading to uncontrolled thermal propagation, explosions, and safety hazards due to inadequate control of flame and gas emission, which can cause rapid voltage drops and potential harm to users.
Innovation Solution
A battery pack structure with a melting bolt that separates at a predetermined temperature to control flame and gas release, inflate the pack cover, and maintain sealing, using a plastic material to enhance thermal safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple battery modules are connected to increase energy capacity, then the energy storage capability is improved, but the risk of thermal chain reaction between modules increases
Solution Approach 1:
The battery pack is divided into multiple independent battery modules, each enclosed in its own module case with partition walls. This segmentation isolates thermal events to specific modules, preventing chain reactions while maintaining high energy capacity through the combination of multiple modules.
Solution Approach 2:
A melting bolt acts as a thermal intermediary between battery modules. When thermal runaway occurs in one module, the melting bolt melts at a predetermined temperature, creating a controlled gap that blocks flame and gas propagation to adjacent modules, thus mediating the thermal interaction between modules.
2Reliability
If the battery module structure is made more robust to contain thermal events, then thermal safety is improved, but the control of flame and gas emission is reduced
Solution Approach 1:
The module case incorporates a melting bolt that dynamically responds to thermal conditions. Under normal conditions, the bolt maintains structural integrity for containment. During thermal runaway, the bolt melts to create controlled emission pathways, thus adapting the containment structure to thermal safety needs while maintaining emission control.
Solution Approach 2:
The melting bolt utilizes phase transition from solid to liquid at a predetermined temperature. This phase change enables the bolt to transition from a containment structure to an emission control mechanism, allowing controlled flame and gas release while maintaining overall thermal safety through the module case structure.
3Strength
If the pack cover is made rigid to maintain structural integrity, then mechanical strength is improved, but the ability to inflate and control internal pressure during thermal events is reduced
Solution Approach 1:
The pack cover is designed as a deformable structure that can inflate during thermal events. This flexible design allows the cover to expand and control internal pressure dynamically, while the overall module case structure maintains structural integrity through the rigid frame and partition walls.
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 controls flame and gas emission, prevents explosions, maintains pack sealing, and ensures electrical safety during thermal events, enhancing overall thermal safety.
Implementation Method 1
a melting bolt fastening the pack cover and the partition wall, and configured to melt at a predetermined temperature
Implementation Method 2
When the discharge of gases or flames is not properly controlled, the gases or flames may be directed toward other battery modules, which may trigger thermal chain reactions in those modules
Data Source
AI summary
A battery pack according to an embodiment of the present disclosure includes: a case providing an internal space and including a pack cover; a battery cell positioned within the case; a partition wall partitioning the internal space of the case; and a melting bolt fastening the pack cover and the partition wall. The melting bolt is configured to melt at a predetermined temperature.