Battery Cell Thermal Barrier With Expanding Gap Isolation
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Solution Overview
Problem
In densely packed battery modules or packs, overheating or thermal runaway in one battery cell can lead to chain thermal runaway or ignition of adjacent cells, due to inadequate heat management.
Innovation Solution
A battery assembly with a thermal barrier disposed between adjacent battery cells, featuring an elastic accommodation member and a thermal expansion material that expands at a first threshold temperature to increase the gap between cells, thereby blocking heat transfer and potentially discharging an extinguishing material at a higher temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple battery cells are densely disposed to increase energy density, then energy density is improved, but thermal runaway risk increases causing chain thermal runaway or ignition of other battery cells
Solution Approach 1:
A thermal barrier is introduced as an intermediary component between adjacent battery cells. This thermal barrier includes a thermal expansion material that remains inactive during normal operation but activates when temperature reaches a first threshold, expanding to increase the gap between cells and block heat transfer. This mediator prevents direct thermal contact between cells while maintaining dense packing during normal conditions.
Solution Approach 2:
The thermal barrier utilizes parameter changes in the thermal expansion material that transitions from a compressed state at normal temperatures to an expanded state when temperature reaches the first threshold. This parameter change (volume expansion) is triggered by temperature increase and automatically increases the separation distance between battery cells, dynamically adjusting the thermal protection level based on operating conditions.
2Reliability
If a thermal barrier is introduced between battery cells to prevent thermal runaway, then thermal safety is improved, but device complexity increases
Solution Approach 1:
The thermal barrier combines multiple functions into a single integrated component: thermal insulation, automatic gap adjustment, and fire suppression. The thermal expansion material provides thermal protection while the extinguishing material provides fire suppression, eliminating the need for separate systems and reducing overall structural complexity despite adding safety functions.
Solution Approach 2:
The thermal barrier operates autonomously without external control systems. When temperature reaches the first threshold, the thermal expansion material automatically expands to increase the gap between cells. When temperature reaches the second threshold, the extinguishing material automatically discharges to suppress fire. This self-service mechanism eliminates the need for sensors, actuators, or control electronics, reducing system complexity.
3Object-affected harmful factors
If the thermal expansion material expands to increase the gap between battery cells, then heat transfer is blocked, but space utilization decreases
Solution Approach 1:
The thermal barrier employs dynamic space adjustment rather than static separation. During normal operation, the thermal expansion material maintains a compressed state, preserving high space utilization and energy density. When thermal runaway risk is detected (temperature reaches first threshold), the material dynamically expands to create thermal separation. This dynamic adaptation allows the system to optimize between space utilization and thermal protection based on real-time conditions.
Solution Approach 2:
The thermal expansion material is strategically positioned only at critical interfaces between adjacent battery cells where thermal runaway propagation risk is highest. This localized placement provides targeted thermal protection exactly where needed, rather than uniformly increasing gaps throughout the entire battery pack, thereby minimizing the impact on overall space utilization while maximizing thermal safety at critical points.
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 thermal barrier effectively suppresses or delays overheating or thermal runaway of battery cells, preventing chain thermal runaway or ignition by blocking heat transfer and providing a fire-extinguishing function.
Implementation Method 1
a thermal expansion material accommodated in the accommodation space and configured to expand at a first threshold temperature or above to increase a gap between the two adjacent battery cells
Implementation Method 2
the elastic accommodation member may be configured to melt at a second threshold temperature or above, which is higher than the first threshold temperature
Data Source
AI summary
A battery assembly according to an aspect of the present disclosure may include a plurality of battery cells and a thermal barrier disposed between two adjacent battery cells among the plurality of battery cells. The thermal barrier may include an elastic accommodation member having an accommodation space, and a thermal expansion material accommodated in the accommodation space and configured to expand at a first threshold temperature or above to increase a gap between the two adjacent battery cells.