Perforated Resin-Encapsulated Insulation Sheet for Battery Packs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat insulating sheets for battery packs face challenges in manufacturing with dry type silica or silica aerogel, as they aggregate when wet and have poor dispersion, leading to increased thermal conductivity and reduced quality. Additionally, dry type molding methods can cause inorganic particles to fall off, contaminating the battery case.
Innovation Solution
A heat transfer suppression sheet comprising a heat insulating material with inorganic particles and organic fibers, encapsulated in a resin film with holes. The resin film has different hole area ratios on its surfaces, which helps in suppressing heat transfer and preventing powder falling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If dry type silica or silica aerogel is used to improve heat insulating performance, then thermal conductivity is reduced, but the material aggregates when wet and cannot be manufactured by wet type sheet forming method
Solution Approach 1:
The patent uses a hydrophobic coating as an intermediary substance applied to the surface of dry type silica particles. This coating prevents water from directly contacting and aggregating the silica particles during the wet type sheet forming process, enabling successful manufacturing while maintaining the low thermal conductivity of the silica material
Solution Approach 2:
The patent changes the surface property parameter of the silica particles by applying a hydrophobic coating, transforming them from water-attracting to water-repelling. This parameter change allows the particles to remain dispersed in water during manufacturing while maintaining their inherent low thermal conductivity properties
2Temperature
If dry type molding method is used to manufacture heat insulating sheet, then heat insulating performance is maintained, but inorganic particles fall off due to pressure or impact
Solution Approach 1:
The patent uses a resin film as a flexible shell that encapsulates the heat insulating material containing dry type silica particles. This film prevents particles from falling off due to pressure or impact during battery assembly and operation, while the film's flexibility allows it to conform to the battery cell surfaces
Solution Approach 2:
The patent creates a composite structure combining the resin film with the heat insulating material (dry type silica particles). This composite approach integrates the protective function of the resin film with the thermal insulation function of the silica particles, solving both the particle falling off problem and maintaining heat insulating performance
3Stress or pressure
If gas is discharged from peripheral edge portion of heat insulating material during thermal runaway, then internal pressure is relieved, but inorganic particles are jetted out and contaminate battery case
Solution Approach 1:
The resin film acts as a containment shell that covers the entire heat insulating material, including the peripheral edges. When gas pressure builds up during thermal runaway, the film contains the particles while allowing controlled gas discharge, preventing particle jetting and contamination of the battery case
Solution Approach 2:
The composite structure of resin film plus heat insulating material creates a unified component where the film provides both structural integrity and particle containment. During thermal events, this composite design ensures that pressure relief occurs without particle ejection
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 provides excellent heat insulating properties while preventing contamination from powder falling, effectively suppressing thermal runaway and flame expansion in battery packs.
Implementation Method 1
heat transfer suppression sheet containing: a heat insulating material that includes inorganic particles and an organic fiber; and a resin film that encompasses the heat insulating material
Implementation Method 2
a hydrophobic coating that is formed on a surface of each inorganic particle
Data Source
Figure 1~2
Figure 3
AI summary
There is provided a heat transfer suppression sheet which has excellent heat insulating properties and also makes it possible to suppress the contamination of the periphery due to powder falling. A heat transfer suppression sheet (10) has a heat insulating material (11) including inorganic particles and organic fibers, and a resin film (12) encompassing the heat insulating material (11). The resin film (12) has holes (13) and is composed of a first surface-side film (12a) and a second surface-side film (12b) that are respectively disposed on a first surface side and a second surface side which are orthogonal to a thickness direction of the heat insulating material (11), and an end surface-side film (12c) that is disposed on an end surface side parallel to the thickness direction of the heat insulating material. In addition, an area ratio of the holes (13) in the first surface-side film (12a) and the second surface-side film (12b) to the total area of the first surface-side film (12a) and the second surface-side film (12b) is larger than an area ratio of the holes (13) in the end surface-side film (12c) to the total area of the end surface-side film (12c).