Traction Battery Case Shielding for Thermal Runaway Containment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing battery boxes for traction batteries face challenges in preventing thermal runaway and mechanical protection, with high-temperature-resistant materials offering little mechanical protection and deteriorating under mechanical stress, and existing insulation methods failing to effectively prevent flame penetration and heat transfer.

Innovation Solution

A two-layer shielding element is positioned between battery modules, comprising a first outer layer made of lightweight aluminum and a second outer layer made of high-temperature-resistant steel, optionally with an insulation layer in between, designed to delay or prevent flame penetration and heat transfer, while being adaptable to the 3D shape of the battery box.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If high-temperature-resistant materials are used to prevent thermal runaway, then thermal protection is improved, but mechanical protection is insufficient and the protective effect diminishes over time under mechanical stress

Engineering Contradiction:
Improvethermal protectionVSAvoidmechanical protection
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The patent applies composite materials by combining a metal layer (steel or aluminum) with an insulating layer (ceramic, glass fiber, or mineral wool) to create a shielding element that provides both mechanical strength and thermal insulation. This composite structure resolves the contradiction by integrating the advantages of both material types: the metal provides structural integrity while the insulating layer provides thermal protection.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The shielding element is positioned locally between battery modules or between battery modules and the battery box wall, providing targeted thermal and mechanical protection where it is most needed. This local placement optimizes the protective effect while reducing overall material usage and maintaining mechanical strength in critical areas.

Inventive Principle:
Principle #3Local quality

2Strength

If a single metal layer is used for the shielding element, then mechanical protection is improved, but thermal insulation effectiveness is reduced

Engineering Contradiction:
Improvemechanical protectionVSAvoidthermal insulation
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The patent uses composite materials by combining a metal layer (steel or aluminum) with an insulating layer (ceramic, glass fiber, or mineral wool) to create a shielding element that provides both mechanical strength and thermal insulation. This composite structure resolves the contradiction by integrating the advantages of both material types: the metal provides structural integrity while the insulating layer provides thermal protection.

Inventive Principle:
Principle #40Composite materials

3Temperature

If thick insulating layers are used to prevent heat transfer, then thermal insulation is improved, but mechanical stability and 3D shape maintenance deteriorate

Engineering Contradiction:
Improvethermal insulationVSAvoidmechanical stability
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The patent uses composite materials by combining a metal layer (steel or aluminum) with an insulating layer (ceramic, glass fiber, or mineral wool) to create a shielding element that provides both mechanical strength and thermal insulation. This composite structure resolves the contradiction by integrating the advantages of both material types: the metal provides structural integrity while the insulating layer provides thermal protection.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The shielding element can be designed as a thin-walled structure where the metal layer provides the necessary mechanical stability and 3D shape maintenance, while the insulating layer (even when thin) provides adequate thermal insulation when combined with the reflective properties of the metal surface.

Inventive Principle:
Principle #30Flexible shells and thin films

4Weight of moving object

If lightweight materials are used for the shielding element, then weight is reduced, but mechanical protection and flame penetration resistance are insufficient

Engineering Contradiction:
Improveshielding element weightVSAvoidflame penetration resistance
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent uses composite materials by combining a metal layer (steel or aluminum) with an insulating layer (ceramic, glass fiber, or mineral wool) to create a shielding element that provides both mechanical strength and thermal insulation. This composite structure resolves the contradiction by integrating the advantages of both material types: the metal provides structural integrity while the insulating layer provides thermal protection.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The shielding element is positioned locally between battery modules or between battery modules and the battery box wall, providing targeted thermal and mechanical protection where it is most needed. This local placement optimizes the protective effect while reducing overall material usage and maintaining mechanical strength in critical areas.

Inventive Principle:
Principle #3Local quality

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 shielding element effectively prevents thermal runaway from spreading to adjacent modules, maintains battery modules within their nominal temperature range, and provides mechanical protection, delaying flame penetration into the vehicle for at least 5 minutes, while being lightweight and cost-effective.

Implementation Method 1

a first outer metallic layer (11) and a second outer metallic layer (12)... delaying flame penetration into the vehicle for at least 5 minutes

Methodology Applied
Scientific EffectThermal radiation blocking: Reflection

Implementation Method 2

designed to delay or prevent flame penetration and heat transfer

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3948973B1Battery case
Publication Date: 2025.09.17 REINZ DICHTUNGS G M B H
  • EP3948973B1 patent drawingFigure 1A~1C
  • EP3948973B1 patent drawingFigure 2~3
  • EP3948973B1 patent drawingFigure 4~5

AI summary

The invention relates to a battery case for a traction battery, and to the use thereof to hold traction batteries in vehicles.