Battery Module Heat-Blocking Sheet for Thermal Runaway Containment
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Solution Overview
Problem
Lithium secondary batteries in battery modules and packs are prone to rapid thermal runaway and chain ignition due to uncontrolled heat propagation, leading to structural collapse and potential explosions, especially when one battery cell triggers a thermal event.
Innovation Solution
Incorporation of a heat propagation blocking sheet made of silicone polymer that ceramicizes upon heating, covering parts of the battery cell stack to absorb heat, block gas and flame, and enhance mechanical rigidity, thereby preventing structural collapse and delaying ignition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If battery modules are densely arranged to increase energy density, then productivity and space utilization are improved, but heat propagation speed increases and thermal runaway spreads rapidly to surrounding modules
Solution Approach 1:
A heat propagation blocking sheet is introduced as an intermediary component between battery cells and modules. This sheet is positioned at specific locations where heat propagation paths are most critical, acting as a physical barrier that interrupts thermal runaway spread while allowing the battery pack to maintain high energy density through optimized spatial arrangement.
Solution Approach 2:
The battery pack is segmented into multiple zones by strategically placing heat propagation blocking sheets between individual cells and modules. This segmentation divides the continuous thermal propagation path into isolated sections, preventing chain reactions from spreading throughout the entire pack while maintaining compact design.
2Ease of manufacture
If plastic materials are used for front cover and rear cover to provide insulation, then ease of manufacture and electrical insulation are improved, but structural strength decreases and collapse occurs easily during thermal runaway
Solution Approach 1:
The heat propagation blocking sheet is constructed as a composite material structure combining heat-resistant ceramic fibers for thermal stability, metal mesh or aluminum foil for structural reinforcement and heat reflection, and plastic resin for electrical insulation and ease of manufacturing. This composite approach integrates multiple functions into a single component that maintains structural integrity during thermal events while providing necessary insulation properties.
3Strength
If aluminum material is used for module case to provide structural support, then strength is improved, but thermal melting point is low and vulnerability to thermal runaway increases
Solution Approach 1:
The heat propagation blocking sheet serves as a protective intermediary layer between the aluminum module case and the battery cells. This barrier prevents direct exposure of the aluminum case to extreme temperatures and thermal runaway byproducts, allowing the case to maintain its structural support function without being compromised by thermal events.
Solution Approach 2:
The heat propagation blocking sheet causes thermal runaway heat to skip over the aluminum case rather than directly heating it. By positioning the heat-resistant barrier between the source of thermal runaway and the case, the heat energy is absorbed and blocked before reaching the temperature-sensitive aluminum material.
4Reliability
If heat propagation blocking sheet is added to prevent thermal runaway spread, then reliability is improved, but device complexity increases
Solution Approach 1:
The heat propagation blocking sheet is designed as a thin, flexible barrier that can be easily installed between battery cells and modules. This thin-film approach provides effective thermal blocking without adding significant structural complexity or volume to the battery pack design.
Solution Approach 2:
Multiple functions are merged into the heat propagation blocking sheet: thermal blocking, structural reinforcement, electrical insulation, and ease of manufacturing. By combining these functions into a single integrated component rather than separate elements, the overall device complexity is minimized while achieving comprehensive thermal safety.
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 heat propagation blocking sheet effectively suppresses temperature rise and prevents structural collapse of the battery module, reducing the risk of chain ignition and explosion by absorbing heat and blocking high-temperature gases and particles, thus enhancing safety.
Implementation Method 1
a heat propagation blocking sheet made of silicone polymer that ceramicizes upon heating, covering parts of the battery cell stack to absorb heat
Implementation Method 2
The heat propagation blocking sheet effectively suppresses temperature rise and prevents structural collapse of the battery module, reducing the risk of chain ignition and explosion by absorbing heat and blocking high-temperature gases and particles
Implementation Method 3
blocking gas and flame, and enhance mechanical rigidity, thereby preventing structural collapse and delaying ignition
Data Source
AI summary
A battery module includes a cell stack including a plurality of battery cells, a module case in which the cell stack is accommodated, and a heat propagation blocking sheet including a heat-resistant material, which covers at least a portion of the cell stack inside the module case.