Battery Pack Interface Sealing for Cell Vent Gas Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing traction battery packs for electrified vehicles face challenges in effectively managing cell venting during thermal events, leading to potential gas leakage and reduced safety and performance.
Innovation Solution
A seal system is implemented within the traction battery pack, utilizing a combination of bulb seals, adhesives, and structural barriers to seal interfaces between the heat exchanger plate, thermal barrier assemblies, structural plate members, and cross-member assemblies, thereby controlling gas paths and preventing vent gases from passing between cell packets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a seal system is implemented to prevent gas leakage between cell packets, then safety and vent gas control are improved, but device complexity increases due to multiple seals and adhesives
Solution Approach 1:
The battery pack is segmented into multiple cell packets with thermal barrier assemblies separating them. Each interface between cell packets is sealed independently with seals and adhesives, creating discrete containment zones that prevent gas leakage while maintaining manageable complexity through modular segmentation.
Solution Approach 2:
Thermal barrier assemblies serve as intermediary structures between adjacent cell packets. These assemblies incorporate seals and adhesives at their interfaces with heat exchanger plates and structural components, acting as mediators that simultaneously provide thermal isolation and gas sealing functions.
2Manufacturing precision
If multiple seals are used to seal interfaces between heat exchanger plate and structural components, then gas path control is improved, but manufacturing complexity increases
Solution Approach 1:
Seals and adhesives are pre-applied to thermal barrier assemblies and structural components before final assembly. This preliminary action ensures proper sealant placement and bonding surface preparation, achieving precise gas path control while simplifying the manufacturing process by preparing components in advance rather than during final assembly.
Solution Approach 2:
The seal system is designed to be self-aligning and self-sealing through the interaction of bulb seals with grooves in structural barriers, and adhesives that flow to fill gaps. This self-service mechanism reduces the need for precise manual alignment during assembly, improving gas path control while easing manufacturing complexity.
3Reliability
If bulb seals with dome-like portions are used to seal interfaces, then sealing effectiveness is improved, but device complexity increases
Solution Approach 1:
Bulb seals with dome-like portions are used at critical interfaces between thermal barrier assemblies and heat exchanger plates. The flexible dome structure can deform to accommodate manufacturing tolerances and thermal expansion, maintaining sealing effectiveness while the bulb seal's integrated design (combining mounting flange and sealing portion) actually reduces overall device complexity compared to separate sealing components.
Data Source
AI summary
Battery cell stack designs are provided for traction battery packs. An exemplary cell stack may include a thermal barrier assembly that is arranged to inhibit the transfer of thermal energy between adjacent cell packets of battery cells of the cell stack. The thermal barrier assembly may include a first seal for sealing a first interface between a heat exchanger plate and the thermal barrier assembly. A second seal may be provided for sealing a second interface between the heat exchanger plate and a structural plate member of the cell stack. A third seal may be provided for sealing a third interface between the heat exchanger plate and cross-member assembly of the cell stack. The first, second, and third seals may cooperate to establish a seal system for sealing various gas paths across the heat exchanger plate, thereby preventing vent gases from passing from one battery cell packet to another during battery thermal events as part of a cell vent management strategy.