Battery Pack Venting Path Design for Thermal Runaway Safety
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Solution Overview
Problem
Existing battery packs face challenges in managing thermal runaway, which can lead to destructive events due to uncontrolled venting of hot gases and the risk of electrical arcing, compromising safety and efficiency.
Innovation Solution
The battery pack design incorporates a housing with crossbeams that separate accommodation chambers, ensuring each cell unit has a dedicated venting path to a venting device without passing adjacent units, along with spacers and a disconnecting member to manage voltage and prevent arcing, enhancing safety and manufacturability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If battery cells are arranged in a compact configuration to increase energy density, then productivity and space utilization are improved, but thermal management becomes more difficult and the risk of thermal runaway propagation increases
Solution Approach 1:
The battery pack is divided into multiple accommodation chambers separated by crossbeams, with each chamber containing one or more cell units. This segmentation isolates thermal events to specific chambers, preventing propagation to adjacent cells while maintaining compact overall configuration for high energy density.
Solution Approach 2:
Different regions of the battery pack are assigned different functions: accommodation chambers for cell containment, crossbeam regions for structural support and thermal isolation, and venting device regions for pressure relief. This local differentiation optimizes thermal management while preserving compact design.
2Reliability
If venting paths are provided for each cell unit to manage thermal runaway, then safety is improved, but device complexity increases due to additional venting devices and path routing
Solution Approach 1:
The crossbeams serve multiple functions: they provide structural support for the battery pack, act as thermal barriers between accommodation chambers, and serve as mounting structures for venting devices. This multi-functionality reduces overall system complexity while maintaining safety.
Solution Approach 2:
Multiple venting paths from different cell units converge to share common venting devices located in the crossbeam structures. This merging approach maintains individual cell isolation for safety while reducing the total number of venting devices needed, thereby simplifying the system.
3Reliability
If spacers are stacked between cell units to separate them, then thermal runaway propagation is prevented, but manufacturing complexity increases due to additional assembly steps
Solution Approach 1:
Spacers are pre-positioned between cell units during the assembly process, establishing thermal isolation before cells are fully secured. This preliminary action ensures thermal protection is built into the structure from the beginning, simplifying subsequent assembly steps.
Solution Approach 2:
The spacers are nested within the overall cell unit assembly structure, fitting into the spaces between cells without requiring separate mounting operations. This nesting approach integrates thermal isolation components into the existing assembly workflow, maintaining ease of manufacture.
4Reliability
If a disconnecting member is provided to prevent electrical arcing during thermal runaway, then safety is improved, but device complexity increases due to additional electrical isolation mechanisms
Solution Approach 1:
The disconnecting member is extracted as a separate, dedicated component that can be independently controlled and positioned. This extraction allows for simple electrical isolation functionality without integrating complex control systems into the existing battery management architecture.
Solution Approach 2:
The disconnecting member acts as an intermediary element between cell units, providing electrical isolation when needed without interfering with normal operational electrical connections. This mediator approach enables safety functionality while maintaining simple electrical architecture during normal operation.
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
This design effectively contains vent gases and reduces the risk of total destruction by guiding vent gases to specific venting devices, minimizing the risk of arcing and improving safety performance while simplifying assembly.
Implementation Method 1
Thermal runaway describes a thermal event, i.e., a process, that is accelerated by increased temperature, in turn releasing energy that further increases temperature. Thermal runaway occurs in situations where an increase in temperature changes the conditions in a way that causes a further increase in temperature
Implementation Method 2
The vent gas also causes a gas-pressure increase inside the battery pack
Data Source
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AI summary
The present disclosure refers to a battery pack (10), comprising: a battery housing (16) providing an interior space and comprising a plurality of crossbeams (12a, 12b, 12c, 12d) dividing the interior space of the battery housing (16) into a plurality of separated accommodation chambers (17a, 17b, 17c), a plurality of cell units (30a, 30b, ..., 30i) arranged within the battery housing (16), wherein each of the cell units (30a, 30b, ..., 30i) comprises a plurality of stacked battery cells (20), wherein each of the accommodation chambers (17a, 17b, 17c) accommodates at least two of the plurality of cell units (30a, 30b, ..., 30i) separated by at least one spacer (31) stacked between the at least two cell units (30a, 30b, ..., 30i), and at least one venting path (32) per cell unit (30a, 30b, ..., 30i), wherein each venting path (32) connects the respective cell unit (30a, 30b, ..., 30i) with a respective venting device (33) of the corresponding accommodation chamber (17a, 17b, 17c) without passing an adjacent cell unit (30a, 30b, ..., 30i).