Traction Battery Pack Edge Immersion Cooling With Thermal Barriers
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Solution Overview
Problem
Existing thermal management systems for traction battery packs struggle to effectively control both convective and conductive heat transfer, leading to potential thermal events and cascading heat issues.
Innovation Solution
A thermal management system utilizing immersion cooling with dielectric coolant and multi-layered thermal barriers to limit convective and conductive heat transfer, respectively, by contacting minor side surfaces of battery cells and using thermally insulating materials to block conductive heat transfer between cell groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional thermal management systems are used, then the system structure is simpler, but the system cannot effectively control both convective and conductive heat transfer leading to thermal events
Solution Approach 1:
The battery pack is divided into multiple cell groups with thermal barriers between them, segmenting the thermal management function. Each cell group can be independently managed, preventing thermal events from cascading across the entire pack while maintaining overall system reliability.
Solution Approach 2:
Thermal barriers are introduced as intermediary elements between cell groups to specifically address conductive heat transfer. These barriers act as mediators that block thermal pathways without requiring complete system redesign, improving reliability with moderate complexity addition.
2Object-affected harmful factors
If thermal barriers are added between cell groups, then conductive heat transfer is limited, but the device complexity increases
Solution Approach 1:
Thermal barriers are placed specifically at locations where conductive heat transfer is most problematic - between cell groups rather than throughout the entire battery pack. This localized approach addresses the harmful factor of conductive heat transfer while minimizing the increase in device complexity.
Solution Approach 2:
The thermal barriers utilize composite material structures that provide effective thermal isolation with minimal thickness. By using materials with superior thermal barrier properties, the physical space and structural complexity added to the cell stack is reduced.
3Object-affected harmful factors
If immersion cooling is implemented, then convective heat transfer is controlled, but the system complexity and hardware size increase
Solution Approach 1:
The immersion cooling system merges the coolant circulation function with the existing battery pack structure. The coolant flows through channels that are integrated into the cell stack design, combining thermal management with structural support functions to reduce overall system complexity.
Solution Approach 2:
The thermal management system is designed to perform multiple functions: convective cooling through coolant circulation, conductive barrier provision through thermal barriers, and structural support. This multi-functionality reduces the need for separate dedicated components, thereby controlling system complexity.
4Power
If high-rate charging and discharging are enabled, then power output increases, but thermal management challenges and thermal event risks increase
Solution Approach 1:
By segmenting the battery pack into isolated cell groups with thermal barriers, high-rate charging and discharging can be performed in each group independently. This segmentation contains thermal events within individual groups, allowing high power operation without compromising overall pack reliability.
Solution Approach 2:
Thermal barriers serve as intermediaries that allow high-rate charging and discharging to proceed by blocking the propagation of thermal events. These barriers enable aggressive power cycling in individual cell groups while protecting the entire pack from thermal runaway.
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 system effectively manages thermal energy levels, preventing thermal events from cascading and allowing high-rate charging and discharging without increasing hardware size, while maintaining electrical safety.
Implementation Method 1
the coolant is configured to limit a convective transfer of thermal energy resulting from the release of the vent byproduct
Implementation Method 2
the thermal barrier is configured to limit a conductive transfer of thermal energy between the first group and the second group
Data Source
AI summary
Thermal management systems are provided for managing thermal energy in a traction battery pack. An exemplary thermal management system may utilize a combination of immersion cooling for limiting convective heat transfer and thermal barriers for limiting conductive heat transfer across one or more cell stacks of the traction battery pack. The immersion cooling may provide an edge cooling scheme in which coolant is directed across minor side surfaces (e.g., top, bottom, and ends) of battery cells of the cell stacks but does not contact major side surfaces (e.g., faces) of the battery cells. The thermal barriers may include a single layer or multiple layers of one or more thermally resistant materials (e.g., mica, aerogel, etc.).