Battery Module Venting Guide for Thermal Runaway Delay
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Solution Overview
Problem
Existing battery modules face challenges in effectively managing thermal events, which can lead to rapid heat propagation and ignition between battery cells, making it difficult to extinguish thermal events and potentially causing explosions.
Innovation Solution
A battery module design featuring a venting guide unit with a needle member and stopper member that allows controlled discharge of high-temperature gas and particles through gas venting holes, combined with barrier plates to restrict heat and gas movement, and a bus bar frame for electrical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple lithium secondary batteries are connected in series and/or parallel to satisfy high output and capacity requirements, then the energy source capability is improved, but the risk of thermal propagation and fire spread increases
Solution Approach 1:
The patent divides the battery module into multiple stacks, with each stack containing a subset of battery cells. This segmentation isolates thermal events to specific stacks, preventing rapid propagation across the entire module while maintaining high overall capacity through parallel connections between stacks.
Solution Approach 2:
The patent introduces gas venting holes and venting guide units as intermediary structures between battery cells and stacks. These intermediaries provide controlled pathways for gas discharge during thermal events, reducing pressure buildup and preventing uncontrolled thermal runaway propagation between cells.
2Reliability
If gas venting holes are provided in the module case to discharge thermal energy, then thermal runaway propagation is delayed, but the structural integrity and sealing of the module case is compromised
Solution Approach 1:
The patent implements gas venting holes at specific locations (bottom plate of module case) rather than throughout the entire case structure. This localized approach provides thermal relief where most needed while preserving the sealing and structural integrity of the main module case body.
Solution Approach 2:
The gas venting system is designed with asymmetric placement at the bottom of the module case, utilizing gravity to facilitate gas discharge downward while maintaining upward sealing. The venting guide unit's asymmetric needle configuration directs gas flow in specific patterns to optimize discharge while minimizing impact on overall case integrity.
3Productivity
If a needle member is designed to pop up from the gas venting hole to make a hole in the battery cell, then early discharge of high-temperature gas is achieved, but the control and reliability of the venting mechanism is reduced
Solution Approach 1:
The needle member is pre-positioned in a blocked state within the venting guide unit, ready to rapidly deploy when thermal conditions trigger it. This preliminary positioning ensures that when activation occurs, the needle can immediately puncture the battery cell pouch and establish gas discharge pathways without delay.
Solution Approach 2:
The needle member is designed to activate automatically in response to thermal events through self-contained mechanisms (such as thermal expansion or pressure-driven movement), eliminating the need for external control systems. The venting guide unit's structure guides the needle's self-actuation, ensuring reliable operation without adding complex control electronics that could fail.
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 design effectively relieves heat and pressure within the battery module by early discharge of high-temperature gas and particles, reducing thermal damage to adjacent cells and delaying thermal runaway.
Implementation Method 1
The needle stopper member may be made of a material heat-meltable at a predetermined temperature.
Implementation Method 2
The needle member may include an elastic member disposed vertically in the gas venting hole; a needle portion coupled to a top end of the elastic member
Data Source
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AI summary
Disclosed is a battery module, which includes a cell stack including stacked battery cells; a module case configured to accommodate the cell stack and having a gas venting hole formed in a bottom plate located at a lower portion of the cell stack; and a venting guide unit including a needle member configured to be popped up from the gas venting hole to make a hole in the battery cell, and a needle stopper member configured to prevent the needle member from being popped up while deformation by heat or external force does not occur.