Granular Cell Insulation to Block Battery Thermal Runaway
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries are prone to thermal runaway due to heat sensitivity, which can lead to catastrophic chain reactions and fires, as they are not effectively insulated to prevent heat transfer between cells.
Innovation Solution
A battery design incorporating a granular insulating material, such as microporous insulation with endothermic compounds, is used to fill the interstices between cells, absorbing heat and preventing thermal runaway by maintaining the temperature below 250° F during high thermal exposures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lithium-ion cells are placed in direct contact or close proximity to maximize battery density, then the battery achieves higher energy density and smaller size, but heat transfer between cells increases the risk of thermal runaway
Solution Approach 1:
The patent introduces an insulating material as an intermediary substance placed in the interstices between battery cells. This material acts as a thermal barrier that prevents direct heat transfer between adjacent cells while occupying the space that would otherwise allow thermal conduction, thus resolving the contradiction between cell proximity and thermal isolation
Solution Approach 2:
The patent specifies using microporous insulating materials with controlled porosity (30-70% void volume) to fill the interstices between cells. The porous structure provides thermal insulation while maintaining flexibility and adaptability to different cell geometries, enabling thermal protection without sacrificing battery density
2Reliability
If insulating material is added between cells to prevent heat transfer, then thermal protection improves, but the battery volume increases and energy density decreases
Solution Approach 1:
The patent applies insulating material selectively only in the interstices and gaps between cells rather than uniformly throughout the entire battery assembly. This partial application provides thermal protection at the critical heat transfer interfaces without unnecessarily increasing overall battery volume, thus resolving the contradiction between thermal protection and volume efficiency
Solution Approach 2:
The patent specifies insulating materials with controlled porosity parameters (30-70% void volume) and specific thermal conductivity ranges (0.03-0.15 W/m·K). By optimizing these material parameters, the invention achieves effective thermal insulation with minimal material volume, resolving the contradiction between thermal protection and battery compactness
3Reliability
If microporous insulating material with endothermic compounds is used, then heat absorption capability increases and thermal runaway prevention improves, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines microporous insulating material with endothermic compounds to create a composite insulation material that provides both thermal barrier properties and active heat absorption through phase change. This composite approach enhances thermal runaway prevention by utilizing multiple mechanisms simultaneously, justifying the increased material complexity through superior safety performance
Solution Approach 2:
The endothermic compounds in the insulating material automatically absorb heat during thermal events through phase change without requiring external control systems or active intervention. This self-service mechanism provides thermal protection that activates automatically when needed, reducing the need for complex monitoring and control 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 granular insulation effectively shields adjacent cells from heat, reducing the risk of thermal runaway and preventing fires by absorbing heat and maintaining the insulation material's temperature below 250° F, even during exposures up to 2000° F, thus enhancing the safety of lithium-ion batteries.
Implementation Method 1
one of the compounds in the microporous insulation may be an endothermic compound that absorbs heat applied to the microporous insulation
Implementation Method 2
The interstices between the cells are filled with a granular insulating material
Data Source
AI summary
A battery arrangement for fire suppression. The battery has a plurality of cells, each having an outer surface. A portion of the surfaces of adjacent cells are spaced from each other. Space between the cells is filled with a granular insulating material. The granular insulation may be a microporous insulation. In the case that microporous insulation is used, one of the compounds in the microporous insulation may be an endothermic compound that absorbs heat applied to the microporous insulation.