Inorganic Fire Barrier Coating for EV Battery Thermal Runaway

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current solutions for preventing thermal runaway in electric vehicle battery modules are inadequate, as they either fail to provide sufficient thermal insulation or are costly, and bonding dissimilar materials together poses flammability issues.

Innovation Solution

A fire barrier article comprising a flame-resistant substrate layer with a fire protection coating, using an inorganic binder and filler, applied to a mica board or paper, which forms a protective ceramic surface under thermal runaway conditions, offering structural integrity and high thermal insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fire protective coatings are used, then fire resistance is provided, but thermal insulation performance is insufficient

Engineering Contradiction:
Improvefire resistanceVSAvoidthermal insulation performance
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent applies composite materials by combining inorganic binder (such as alumina trihydrate, magnesium hydroxide, or calcium carbonate) with inorganic fillers (such as vermiculite, perlite, or silica aerogel) to create a fire protective coating that provides both fire resistance and superior thermal insulation. The composite structure allows the coating to maintain structural integrity while blocking heat transfer during thermal runaway events.

Inventive Principle:
Principle #40Composite materials

2Temperature

If dissimilar materials are bonded together to create fire barriers, then thermal insulation is improved, but flammability issues arise

Engineering Contradiction:
Improvethermal insulationVSAvoidflammability
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent applies homogeneity by using entirely inorganic materials for both the binder and filler components of the fire protective coating. This eliminates organic flammable substances from the coating composition, ensuring that the entire coating system is non-flammable and does not contribute to fire spread during thermal runaway events.

Inventive Principle:
Principle #33Homogeneity

3Temperature

If thicker fire barrier layers are applied, then thermal insulation performance increases, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvethermal insulation performanceVSAvoidcoating structure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent applies porous materials by incorporating hollow or porous fillers such as silica aerogel, vermiculite, or perlite into the fire protective coating. These porous structures provide exceptional thermal insulation performance with high porosity (50-90% air content), allowing effective heat blocking in thin coating layers (5-50 micrometers), thereby reducing overall device complexity and manufacturing difficulty.

Inventive Principle:
Principle #31Porous 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 solution effectively prevents heat transfer from a failing cell to adjacent cells, providing a high temperature drop and structural integrity, thereby mitigating the risk of thermal runaway and ensuring occupant safety.

Implementation Method 1

a fire barrier article that comprises flame resistant substrate layer having a first major surface and a second major surface and a fire protection coating disposed on a substantial portion of the first major surface of the flame resistant substrate layer

Methodology Applied
Scientific EffectThermal Insulation: Thermal Insulation

Implementation Method 2

it is desirable for a thermal management system to block or absorb the heat and prevent adjacent cells or modules from overheating

Methodology Applied
Scientific EffectHeat Absorption: Absorption (physical)

Implementation Method 3

at least one inorganic particulate material which endothermically releases a nonflammable gas in the presence of heat

Methodology Applied
Scientific EffectEndothermic Reaction: Endothermic Reaction

Data Source

PatentEP4069787B1Flame resistant materials for electric vehicle battery applications
Publication Date: 2024.08.28 3M INNOVATIVE PROPERTIES CO
  • EP4069787B1 patent drawingFigure 1~2

AI summary

A fire protection coating and a fire barrier coated article are provided that comprise an inorganic binder and at least one inorganic filler, wherein the inorganic binder is selected from potassium silicate, sodium silicate, or a combination thereof, and wherein the at least one inorganic filler is selected from kaolin clay, talc, mica, mullite, phlogopite, muscovite montmorillonite, smectite, bentonite, illite, chlorite, sepiolite, attapulgite, halloysite, vermiculite, laponite, rectorite, perlite, and combinations thereof. The fire barrier article comprises flame resistant substrate layer having a first major surface and a second major surface, and a fire protection coating disposed on the first major surface of the flame resistant substrate layer.