Battery Cell Pack Venting Structure for Fire Propagation Control
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Solution Overview
Problem
Battery cell packs are prone to fire propagation due to thermal runaway, where combustion gases and flames from a malfunctioning cell can affect adjacent cells, leading to larger malfunctions or device failure.
Innovation Solution
A battery device with a structure on top of the cell pack featuring an insulating material with weakened portions that form a ventilation passage to direct hot gases and flames away from adjacent cells, combined with a heat- and fire-resistant cover layer and a metal framework for thermal management and physical barriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a ventilation passage is provided to allow combustion gases and flames to escape from a malfunctioning battery cell, then fire propagation to adjacent cells is reduced, but the structural complexity of the battery device increases
Solution Approach 1:
The battery device is segmented into individual cell compartments with separate ventilation passages for each cell. This allows combustion gases and flames from a malfunctioning cell to be contained and directed upward through its own ventilation passage, preventing fire propagation to adjacent cells while maintaining a relatively simple overall structure.
Solution Approach 2:
Instead of providing lateral fire barriers between cells (horizontal dimension), the invention uses vertical ventilation passages to direct combustion gases upward (vertical dimension). This dimensional change allows fire suppression without requiring complex lateral containment structures between adjacent cells.
2Object-affected harmful factors
If an insulating material with weakened portions is used to form ventilation passages, then fire and heat propagation is prevented, but the manufacturing precision requirements increase
Solution Approach 1:
The insulating material is pre-formed with weakened portions (such as pre-cuts or scored lines) during the manufacturing process. These weakened portions are designed to rupture at predetermined locations when exposed to thermal runaway conditions, forming ventilation passages automatically. This preliminary preparation simplifies the overall manufacturing process while ensuring consistent performance.
Solution Approach 2:
The insulating material undergoes parameter changes during thermal runaway events, where heat and pressure cause the weakened portions to rupture and form open ventilation passages. The material transitions from a closed, insulating state to an open, venting state, automatically responding to thermal conditions without requiring external control mechanisms.
3Reliability
If the upper surface of the structure is made heat- and fire-resistant, then protection of adjacent cells from flames and hot gases is improved, but the cost of materials and manufacturing increases
Solution Approach 1:
The heat- and fire-resistant properties are applied locally to the upper surface of the structure that directly contacts combustion gases and flames from malfunctioning cells. This localized application provides maximum protection where it is most needed (at the fire interface) while using simpler, less expensive materials for other parts of the battery device structure.
Solution Approach 2:
The battery device structure uses composite materials combining heat- and fire-resistant materials (such as ceramic coatings or fire-retardant polymers) with standard battery housing materials. This composite approach provides the necessary thermal protection at critical interfaces while maintaining cost-effectiveness and manufacturability for the overall device.
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 limits fire and heat propagation by creating a channel for gases and flames to escape above the structure, preventing damage to adjacent cells and maintaining electrical safety, while the metal framework aids in thermal distribution and cooling.
Implementation Method 1
If a battery cell experiences a critical malfunction, it may go into thermal runaway. In this state, combustion gases and flames may develop
Implementation Method 2
The structure includes an insulating material... The insulating material includes a plurality of weakened portions or cuts, which extend through the insulating material... the insulating material prevents fire and combustion gases from reaching cells adjacent to the cell burning out
Implementation Method 3
At least an upper surface of the structure has heat- and fire-resistant properties... The flame- and heat-resistant properties of the upper surface of the structure thus prevents flames and gas to reach the other battery cells
Implementation Method 4
The ventilation passage is formed through the weakened portions or cuts in the insulating material due to an increase in pressure caused by the formation of the flames and gases
Data Source
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AI summary
A battery device (100) comprising a battery cell pack including a plurality of battery cells (118). The battery device further includes a structure (104) disposed on top of the battery cell pack, the structure including an insulating material (106), and a housing (102), in which the battery cell pack and the structure are arranged. At least an upper surface (110) of the structure has heat- and fire-resistant properties. The insulating material includes a plurality of weakened portions or cuts (112) extending through the insulating material. The structure is arranged such that, in case of burnout of a cell (118a), a ventilation passage (116) is formed over the cell through a weakened portion or cut in the insulating material.