Thermoplastic Composite Heat Shielding for Battery Thermal Runaway

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Solution Overview

Problem

Existing materials used in battery housings, such as aluminum and thermoplastic polymer with carbon fibers, struggle to effectively contain high temperatures and jet flames during thermal runaway events, posing safety risks and failing to meet stringent thermal specifications, while also increasing weight and potentially compromising recyclability.

Innovation Solution

A composite material comprising at least one layer of thermoplastic material with selected thermoplastic fibers and reinforcement fibers, where 90 vol% of the reinforcement fibers have an average length of at least 6 mm, enhances temperature resistance and mechanical properties, allowing it to withstand high temperatures and jet flames.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If steel is used for battery housing to provide good resistance against jet flame and heat, then thermal protection is improved, but weight increases substantially

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

Solution Approach 1:

The patent employs a composite material consisting of a thermoplastic polymer matrix reinforced with carbon fibers. This composite provides thermal resistance comparable to steel while achieving significant weight reduction. The carbon fibers enhance the thermal stability and structural integrity of the polymer matrix, allowing the housing to withstand thermal runaway conditions without the substantial weight penalty of steel construction.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If aluminum is used for battery housing to reduce weight, then weight properties are improved, but the material melts quickly when reached directly by thermal propagation flame

Engineering Contradiction:
ImproveweightVSAvoidthermal resistance
Core Design Contradiction:
Weight of moving objectVSTemperature

Solution Approach 1:

The patent employs a composite material consisting of a thermoplastic polymer matrix reinforced with carbon fibers. This composite provides thermal resistance comparable to steel while achieving significant weight reduction. The carbon fibers enhance the thermal stability and structural integrity of the polymer matrix, allowing the housing to withstand thermal runaway conditions without the substantial weight penalty of steel construction.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the thermal properties of the polymer matrix by selecting a thermoplastic polymer with a melting point above 800°C and incorporating carbon fibers that raise the composite's thermal decomposition temperature. This parameter change in the material's thermal characteristics enables the housing to resist thermal propagation flames that would otherwise melt conventional aluminum.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If heavy insulation is added to aluminum housing to improve thermal resistance, then thermal protection is improved, but the risk of burn through remains high and weight increases

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

Solution Approach 1:

The patent employs a composite material consisting of a thermoplastic polymer matrix reinforced with carbon fibers. This composite provides thermal resistance comparable to steel while achieving significant weight reduction. The carbon fibers enhance the thermal stability and structural integrity of the polymer matrix, allowing the housing to withstand thermal runaway conditions without the substantial weight penalty of steel construction.

Inventive Principle:
Principle #40Composite materials

4Weight of moving object

If organic polymer is used for battery housing to reduce weight, then weight properties are improved, but the material can be damaged at temperatures of 600°C and above

Engineering Contradiction:
ImproveweightVSAvoidtemperature resistance
Core Design Contradiction:
Weight of moving objectVSTemperature

Solution Approach 1:

The patent modifies the thermal properties of the polymer matrix by selecting a thermoplastic polymer with a melting point above 800°C and incorporating carbon fibers that raise the composite's thermal decomposition temperature. This parameter change in the material's thermal characteristics enables the housing to resist thermal propagation flames that would otherwise melt conventional aluminum.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite material consisting of a thermoplastic polymer matrix reinforced with carbon fibers. This composite provides thermal resistance comparable to steel while achieving significant weight reduction. The carbon fibers enhance the thermal stability and structural integrity of the polymer matrix, allowing the housing to withstand thermal runaway conditions without the substantial weight penalty of steel construction.

Inventive Principle:
Principle #40Composite materials

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 composite material effectively contains heat and fire within a closed environment, preventing uncontrollable temperature increases and providing a safer, lightweight solution for battery enclosures, extending passenger evacuation time during thermal runaway events.

Implementation Method 1

the composite is capable of withstanding high temperatures, jet flame as well as impact forces associated with thermal and/or heat applications such as a battery thermal runaway event

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

The heat and fire shielding material is based on an at least partial consolidation of a mixture comprising: one or more selected thermoplastic fibers and one or more reinforcement fibers

Methodology Applied
Scientific EffectComposite materials: Composite Materials

Data Source

PatentEP4610043A1Heat and fire shielding thermoplastic composite
Publication Date: 2025.09.03 MITSUBISHI CHEMICAL ADVANCED MATERIALS GMBH
  • EP4610043A1 patent drawingFigure 1A~1B
  • EP4610043A1 patent drawingFigure 2
  • EP4610043A1 patent drawingFigure 3A~3C

AI summary

Use of a composite as a heat and fire shielding material particularly in batteries, wherein the composite comprises at least one layer of a thermoplastic material, wherein said at least one layer is based on an at least partial consolidation of a mixture of: a. one or more thermoplastic fibers selected from the group consisting of polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyether ketone-ketone (PEKK), polyether imide (PEI), polyether sulfone (PES), polysulfone (PSU), polyphenylene sulfone (PPSU), polyimide (PI), polycarbonate (PC), polyamide (PA), polyaryletherketone (PAEK) or any combination thereof; and b. one or more reinforcement fibers; wherein at least 90 vol % of the one or more reinforcement fibers have an average length according to a gaussian normal distribution of at least 6 mm, preferably of at least 10 mm, more preferably of at least 20 mm.