Layered Battery Heat-Shielding Sheet for Fire and Heat Spread

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Solution Overview

Problem

Existing heat-shielding sheets for batteries, particularly those using polyurethane foam, are prone to accelerating fire spread and thermal runaway due to poor heat resistance, and metallic materials are heavy and inefficient in preventing flame and heat dispersion.

Innovation Solution

A heat-shielding sheet comprising a silicone foam layer with laminated flame-retardant, graphite, and barrier layers, incorporating ceramic and fiber fillers, which enhances heat resistance, flexibility, and thermal conductivity while preventing flame and heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If polyurethane foam is used in heat-shielding sheets, then the sheet can provide heat dissipation function, but the fire spreads and thermal runaway is accelerated when fire occurs

Engineering Contradiction:
Improveheat dissipationVSAvoidfire spread
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent uses composite materials by combining silicone foam with multiple functional layers including flame-retardant layer, graphite layer, and barrier layer. This composite structure provides both heat dissipation through the foam structure and fire resistance through the specialized layers, resolving the contradiction between heat dissipation function and fire safety.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameter from polyurethane foam to silicone foam, which inherently possesses better fire resistance while maintaining heat dissipation capabilities. This parameter change allows the material to resist fire spread while still providing thermal management function.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If metallic materials are used for heat dissipation, then thermal conductivity is improved, but the weight increases significantly

Engineering Contradiction:
Improvethermal conductivityVSAvoidweight
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

The patent applies local quality by incorporating graphite layer specifically for thermal conduction where needed, while the bulk structure uses lightweight silicone foam. This localized application of high thermal conductivity material provides efficient heat dissipation paths without requiring the entire structure to be metallic, thus maintaining lightweight characteristics.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses graphite as an intermediary material between the silicone foam and the heat source. Graphite provides excellent thermal conductivity to facilitate heat dissipation while being much lighter than metallic alternatives, serving as a mediator that bridges the gap between thermal performance requirements and weight constraints.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If aluminum is used as thermally conductive filler in polymer resin, then thermal conductivity improves, but the filler is difficult to disperse uniformly and heat transfer path fails to form

Engineering Contradiction:
Improvethermal conductivityVSAvoiduniform dispersion
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The patent extracts the thermal conduction function from the bulk polymer matrix and concentrates it in a dedicated graphite layer. This separation allows the graphite to form continuous heat transfer paths without the dispersion problems encountered when mixing metallic fillers throughout the polymer resin, ensuring both high thermal conductivity and uniform composition.

Inventive Principle:
Principle #2Taking out (Extraction)

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 sheet effectively prevents fire spread and thermal runaway, offering improved heat dissipation and flexibility while being lighter than metallic materials, thus ensuring safer and more efficient battery operation.

Implementation Method 1

a heat-shielding sheet for a battery, the sheet being characterized by including a functional layer sheet, composed of a flame-retardant layer, a graphite layer, a barrier layer, and the like, in silicone foam

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

a graphite layer

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

a flame-retardant layer

Methodology Applied
Scientific EffectFlame retardancy:

Data Source

PatentEP4470767A1Heat-shielding sheet for battery
Publication Date: 2024.12.04 NANOTIM CO LTD
  • EP4470767A1 patent drawingFigure 1A~1B
  • EP4470767A1 patent drawingFigure 1C~2A
  • EP4470767A1 patent drawingFigure 2B~2C

AI summary

Proposed is a heat-shielding sheet for a battery, the sheet sequentially including an inner layer made of a polymer resin, a silicone foam layer, a graphite layer, and a glass bubble layer. Thus, there are advantages of solving the disadvantage of polyurethane foam, used in existing heat-shielding sheets for batteries, that in the event of a fire, the fire spreads and thermal runaway is accelerated, being lighter than metallic materials, and being capable of rapidly preventing flames and heat from spreading.