Battery Assembly Fire-Retardant Inserts for Thermal Runaway Containment

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Solution Overview

Problem

Lithium secondary battery assemblies face safety concerns due to thermal runaway, which can lead to fires and explosions, with empty spaces in battery modules allowing flames to spread easily, posing a significant risk to electric vehicle markets.

Innovation Solution

Incorporating a fire-retardant assembly with a fire-retardant material enclosed in an exterior material that melts at a lower temperature than the fire-retardant material, placed in the empty spaces between battery cells and busbar assemblies, to prevent the spread of hot gas and increase thermal and fire resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If empty spaces are left in battery modules for structural design flexibility, then manufacturing ease and structural adaptability are improved, but fire spread risk increases significantly

Engineering Contradiction:
Improvestructural design flexibilityVSAvoidfire spread risk
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

A fire-retardant assembly is introduced as an intermediary component into the empty spaces between battery cells. This assembly includes a fire-retardant member (such as fire-retardant particles or foam) enclosed within an exterior material housing. The fire-retardant member acts as a barrier that prevents flame and hot gas from spreading through the empty spaces, while the exterior material provides structural containment and facilitates assembly installation without requiring complex manufacturing processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If fire-retardant assemblies are inserted into empty spaces during assembly, then fire resistance is improved, but assembly complexity increases

Engineering Contradiction:
Improvefire resistanceVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fire protection system is segmented into modular fire-retardant assemblies that can be independently manufactured and then inserted into predetermined empty spaces within the battery module. Each assembly is a self-contained unit with a fire-retardant member enclosed in an exterior material housing, allowing for standardized production and simplified installation without requiring complex integration processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fire-retardant assemblies are pre-assembled with the fire-retardant member already enclosed within the exterior material housing before insertion into the battery module. This preliminary assembly action simplifies the final installation process, as the assemblies are ready-to-install units that require minimal on-site assembly or configuration.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If exterior material melts at lower temperature than fire-retardant member, then controlled hot gas venting is achieved, but material selection complexity increases

Engineering Contradiction:
Improvecontrolled hot gas ventingVSAvoidmaterial selection complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The exterior material is specifically selected to undergo a phase transition (melting) at a temperature lower than that of the fire-retardant member. When exposed to high temperatures during thermal runaway, the exterior material melts and creates controlled pathways for hot gas venting, while the fire-retardant member maintains its structural integrity and continues to provide fire barrier function. This differential phase transition behavior enables controlled hot gas release while maintaining fire protection.

Inventive Principle:
Principle #36Phase transitions

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 mitigates the risk of fire spread by directing hot gas along a controlled path and enhancing the thermal and fire resistance of battery assemblies, thereby improving safety and stability in battery applications.

Implementation Method 1

The exterior material may start to melt when a preset temperature is reached. The temperature may be lower than a melting point of the fire-retardant member.

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP4478514A1Battery assembly and method of assembling the same
Publication Date: 2024.12.18 SK ON CO LTD
  • EP4478514A1 patent drawingFigure 1
  • EP4478514A1 patent drawingFigure 2
  • EP4478514A1 patent drawingFigure 3~4

AI summary

Embodiment of the present disclosure relates to a battery assembly including a plurality of battery cells stacked in a preset stacking direction, an accommodation case configured to accommodate the plurality of battery cells, an insertion space formed between the plurality of battery cells and the accommodation case, and a fire-retardant assembly disposed in the insertion space, wherein the fire-retardant assembly includes a fire-retardant member including a fire-retardant material, and a pillar-shaped exterior material configured to accommodate the fire-retardant member therein and extending in a height direction of the accommodation case.