Battery Pack Heat Transfer Member for Thermal Runaway Containment
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Solution Overview
Problem
Existing battery packs face challenges in preventing thermal runaway and rapid heat propagation between tightly packed battery cells, especially when one cell reaches a dangerous temperature, as existing heat transfer members fail to effectively manage thermal energy discharge.
Innovation Solution
A battery pack design incorporating a heat transfer member with an introduction and discharge portion for a cooling fluid, featuring a refrigerant that undergoes phase transition to rapidly cool battery cells, controlled by valves that open at predetermined temperatures, and includes separate heat transfer members between cells to manage thermal energy distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If battery cells are disposed in tight contact with each other to manufacture a battery pack having high energy density, then energy density is improved, but thermal propagation to adjacent battery cells occurs easily
Solution Approach 1:
The patent divides the battery pack into modular units with individual heat transfer members positioned between adjacent battery cells. Each heat transfer member acts as an independent thermal management unit, allowing heat to be dissipated locally before it can propagate to neighboring cells. This segmentation approach maintains tight cell spacing for high energy density while preventing thermal runaway spread.
Solution Approach 2:
The heat transfer member serves as an intermediary substance placed between battery cells to manage thermal interactions. This mediator absorbs excess heat from overheating cells and transfers it to cooling channels, preventing direct thermal contact between adjacent cells while maintaining their tight physical arrangement for optimal energy density.
2Temperature
If a heat transfer member is provided to discharge thermal energy, then temperature control is improved, but the heat transfer member may function as a heat transfer path between battery cells, increasing thermal propagation speed
Solution Approach 1:
The heat transfer member is designed with differentiated functional zones: one surface contacts the battery cell for heat absorption, while the other surface contacts the cooling channel for heat dissipation. The local thermal conductivity and geometry are optimized to favor heat flow toward the cooling channel rather than toward adjacent battery cells, ensuring temperature control without creating a thermal bridge.
Solution Approach 2:
The heat transfer member is pre-positioned between battery cells during assembly, establishing thermal management capability before thermal runaway can occur. The member is designed with thermal characteristics that predispose it to conduct heat preferentially toward the cooling channel, preventing rapid thermal propagation even under extreme conditions.
3Reliability
If existing heat transfer members are used, then heat transfer function is provided, but it is structurally difficult to prevent thermal runaway when battery cell temperature reaches vaporization temperature of working fluid
Solution Approach 1:
The heat transfer member incorporates a phase-change material or working fluid with a vaporization temperature specifically selected to be higher than the maximum operating temperature of the battery cells but lower than the thermal runaway temperature. When cells approach dangerous temperatures, the working fluid undergoes phase change, absorbing large amounts of latent heat and preventing thermal runaway without requiring complex additional safety systems.
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 prevents thermal runaway by rapidly cooling overheated cells and blocking heat transfer to adjacent cells, maintaining safe operating temperatures and enhancing safety in high-density battery packs.
Implementation Method 1
a refrigerant that undergoes phase transition to rapidly cool battery cells
Implementation Method 2
a heat transfer member configured to allow a cooling fluid to be introduced thereinto and to be discharged therefrom to rapidly cool a high-temperature battery cell
Data Source
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AI summary
The present invention relates to a battery pack including a battery cell stack including a plurality of battery cells, a cooling member that cools the battery cell stack, a heat transfer member that discharges heat from the plurality of battery cells to the cooling member, and a pack case that accommodates the battery cell stack, the cooling member, and the heat transfer member therein, wherein the heat transfer member includes an introduction portion and a discharge portion of a cooling fluid. When the temperature of the battery cell is equal to or lower than a dangerous temperature, it is possible to adjust the temperature of each of the battery cells to a predetermined level, and when the temperature of the battery cell is higher than the dangerous temperature, it is possible to rapidly cool the battery cell.