Cell Heat Absorption Sheet Sizing for Thermal Runaway Containment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flame retardant/heat absorption media on battery cells fail to effectively prevent thermal propagation from a cell with thermal runaway to an adjacent cell, lacking universality across different types of cells.
Innovation Solution
A battery assembly with a heat absorption sheet on the cell housing, where the mass and size of the heat absorption material are controlled to meet a specific relation, ensuring effective heat absorption and suppression of thermal propagation while maintaining space utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flame retardant media (such as aerogel) are placed on the housing surface of power cells, then thermal propagation between cells is suppressed, but it is difficult to match with different types of cells and effectively block thermal propagation
Solution Approach 1:
The patent applies parameter changes by establishing a mathematical relationship that connects the mass of heat absorption material to key thermal parameters (heat generation Q_gen, phase change temperature T_p, latent heat H_p, specific heat capacity c_abs). This allows the heat absorption sheet to be precisely designed for different cell types by adjusting material parameters rather than using fixed flame retardant media, thereby achieving both effective thermal propagation suppression and adaptability across different cell configurations
Solution Approach 2:
The patent achieves universality by creating a standardized heat absorption sheet design methodology that can be applied to various cell types. The mathematical formula provides a universal approach to calculate the required heat absorption capacity, making the solution applicable to different cell chemistries and form factors while maintaining effective thermal propagation blocking across all applications
2Reliability
If flame retardant media are placed on cell housing surfaces, then thermal runaway impact on adjacent cells is reduced, but space utilization is extensively affected
Solution Approach 1:
The patent utilizes phase transitions of the heat absorption material to achieve high heat absorption capacity in a compact form. The material undergoes phase change at a specific temperature T_p, absorbing large amounts of latent heat H_p during the transition. This allows the heat absorption sheet to effectively suppress thermal propagation while maintaining a thin, space-efficient structure that does not extensively affect battery pack volume
Solution Approach 2:
By establishing the mathematical relationship between heat absorption material properties and thermal runaway parameters, the patent optimizes the thickness and material composition of the heat absorption sheet. This ensures adequate thermal protection while minimizing the volume occupied by safety components, thereby maintaining high space utilization in the battery assembly
3Reliability
If existing flame retardant media are used on cell surfaces, then thermal runaway suppression is attempted, but the solution lacks universality across different cell types
Solution Approach 1:
The patent resolves the lack of universality by establishing a parameter-based design methodology. The mathematical formula relates the heat absorption material mass to cell-specific thermal parameters (Q_gen, T_p, H_p, c_abs), allowing the same design approach to be adapted to different cell types by inputting their specific thermal characteristics. This creates a universal solution that maintains effective thermal runaway suppression across diverse cell configurations
Solution Approach 2:
The patent introduces the heat absorption sheet as an intermediary component between cells, with its properties determined by a universal calculation formula. This intermediary layer acts as a thermal buffer that can be precisely tailored to match different cell types' thermal runaway characteristics, providing a universal interface that effectively blocks thermal propagation regardless of the specific cell chemistry or design
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 solution effectively suppresses thermal propagation between cells, ensuring safety and high space utilization in battery systems, applicable to various cell types.
Implementation Method 1
T p , H p , and c abs are respectively a phase change temperature, phase change latent heat, and a specific heat capacity of the heat absorption main material
Implementation Method 2
the heat generated by the cell during thermal runaway can be fully absorbed by the heat absorption sheet arranged on the cell
Data Source
Figure 1
Figure 2
AI summary
The present disclosure provides a battery assembly and a device. By controlling a size parameter of a heat absorption sheet arranged on a side surface of a housing of a cell in a battery assembly, a mass of a heat absorption main material, a size parameter of the housing, and related parameters in a thermal runaway process to meet a specific relation, the heat absorption sheet can be ensured to fully suppress heat of a battery with thermal runaway from diffusing to an adjacent battery, and does not excessively affect space utilization of the battery assembly containing a number of cells.