Battery Module Thermal Insulation Spacers with Phase Transition
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Solution Overview
Problem
Existing battery modules face challenges in balancing thermal conductivity for efficient heat dissipation under normal conditions while preventing heat propagation from overheated cells to neighboring cells.
Innovation Solution
Incorporating state transition materials in thermal insulation spacers that undergo an irreversible transformation at a specific temperature, reducing thermal conductivity to limit heat transfer during overheating, combined with high-conductivity materials for end plates and partition plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high thermal conductivity materials are used in end plates and partition plates, then heat dissipation efficiency is improved under normal conditions, but heat propagation risk increases when cells overheat
Solution Approach 1:
The thermal conductivity parameter of the insulation spacers is changed dynamically through phase transition. Below transition temperature, the material maintains high thermal conductivity for efficient heat dissipation. Above transition temperature, the material undergoes phase change to low thermal conductivity state, preventing heat propagation from overheated cells to neighboring cells.
Solution Approach 2:
The insulation spacers utilize phase transition materials that change their thermal conductivity properties at a specific transition temperature. This phase transition mechanism allows the system to automatically adapt thermal management characteristics based on operating temperature conditions, resolving the contradiction between heat dissipation and heat propagation prevention.
2Temperature
If high thermal conductivity is maintained in insulation spacers, then heat flow between cells is promoted at low temperature, but heat transfer to neighboring cells increases when cells overheat
Solution Approach 1:
The thermal conductivity parameter of the insulation spacers is dynamically adjusted through phase transition of the material. At operating temperatures below the transition point, high thermal conductivity promotes efficient heat flow. When cell temperature exceeds the transition point, the material transforms to low thermal conductivity, automatically limiting heat transfer to neighboring cells.
Solution Approach 2:
Phase transition materials are employed in the insulation spacers to achieve temperature-dependent thermal conductivity control. The phase change occurs at a defined transition temperature, enabling the system to switch between heat dissipation mode and heat isolation mode based on thermal conditions.
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
Effectively manages thermal conductivity for efficient heat dissipation under normal conditions and limits heat propagation during overheating, enhancing safety by delaying temperature rise in adjacent cells.
Implementation Method 1
at least one of the thermal insulation spacers is made of a state transition material, which exhibits an initial thermal conductivity higher than an initial thermal conductivity threshold at temperatures below 200°C and, when exposed to temperatures higher than a transition temperature greater than 220°C and less than 320°C, undergoes an irreversible transformation which results in a post-transformation thermal conductivity lower than a post-transformation thermal conductivity threshold
Implementation Method 2
exhibits an initial thermal conductivity higher than an initial thermal conductivity threshold at temperatures below 200°C and, when exposed to temperatures higher than a transition temperature greater than 220°C and less than 320°C, undergoes an irreversible transformation
Data Source
Figure 1~3
Figure 4
AI summary
A battery module (10) comprises two parallel end plates (12) and one or more rows of cells (16) extending in a longitudinal direction (100) of the battery module (10) perpendicular to the two parallel end plates (12), each of the one or more rows of cells (16) comprising a series of prismatic battery cells (20, 22) and thermal insulation spacers (24, 26) repeated alternately along the longitudinal direction (100). At least one of the thermal insulation spacers (24, 26) is made of a state transition material, which exhibits an initial thermal conductivity higher than an initial thermal conductivity threshold (TCT1) at temperatures below 200°C and, when exposed to temperatures higher than a transition temperature (TT) between 220°C and 320°C, undergoes an irreversible transformation which results in a post-transformation thermal conductivity lower than a post-transformation thermal conductivity threshold (TCT2) that is less than the initial thermal conductivity threshold minus 0.5 Wm-1K-1, and less than 0.28 Wm-1K-1.