Battery Housing Vent Path for Controlled Thermal Runaway Release

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Solution Overview

Problem

Existing battery packs lack effective mechanisms to manage thermal runaway events, which can lead to rapid heat propagation, gas release, and potential fire or explosion, necessitating improved thermal management and containment strategies.

Innovation Solution

A battery housing design incorporating a vent channel with dual outlets and a thermal expansion material that expands at a predetermined threshold temperature to block the first outlet, guiding gases through a controlled path and preventing unintended release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a vent channel with dual outlets is used to manage thermal runaway gases, then the control over gas venting path is improved, but the device complexity increases

Engineering Contradiction:
Improvethermal runaway managementVSAvoidventing system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The vent channel is divided into multiple outlets (first outlet and second outlet) with different functions. The first outlet is equipped with thermal expansion material for controlled blocking, while the second outlet remains open for alternative gas escape. This segmentation allows differentiated management of thermal runaway scenarios based on temperature conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Thermal expansion material is introduced as an intermediary substance in the first outlet. This material remains inert during normal operation but activates at specific temperature thresholds, automatically blocking the first outlet when thermal runaway occurs. The intermediary material mediates between the hot gases and the venting system, providing intelligent control without complex sensors or actuators.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If thermal expansion material is placed in the vent channel to block flow at threshold temperature, then the safety control is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvetemperature-responsive safety controlVSAvoidmaterial placement accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The thermal expansion material's key parameter is its expansion temperature threshold, which can be selected and tuned during material formulation. By choosing materials with appropriate expansion temperatures matching expected thermal runaway conditions, the system achieves reliable safety control. The focus shifts from precise placement to selecting materials with the right thermal response characteristics.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The thermal expansion material is pre-positioned in the vent channel during manufacturing, ready to activate automatically when temperature thresholds are reached during operation. This preliminary placement ensures that when thermal runaway occurs, the blocking action happens immediately without requiring real-time control systems or complex assembly procedures during emergency conditions.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If vents are designed to open at specific pressures to release hot gases, then the controlled venting is improved, but the device complexity increases

Engineering Contradiction:
Improvecontrolled hot gas releaseVSAvoidpressure-responsive vent mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The venting system utilizes the thermal runaway process itself to trigger the venting action. The heat from the runaway event directly causes the thermal expansion material to expand and block the first outlet, which in turn directs gases through the second outlet. The system serves itself using the thermal energy already present, eliminating the need for external sensors, actuators, or complex pressure-regulation mechanisms.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The thermal runaway event, which is inherently harmful, is converted into the triggering mechanism for the safety venting system. The heat that signifies dangerous conditions is the same heat that activates the thermal expansion material to block the first outlet and redirect gases through the controlled second outlet. The harmful thermal energy is thus transformed into a beneficial control signal.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 design ensures controlled venting of hot gases, minimizing heat build-up and reducing the risk of further thermal runaway, enhancing safety by providing a responsive and adaptive thermal management system.

Implementation Method 1

a thermal expansion material arranged in a flow path between the opening and the first outlet, the thermal expansion material being configured to expand to prevent a flow through the first outlet at a predetermined threshold temperature

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4597718A1Battery housing with venting path
Publication Date: 2025.08.06 VOLVO TRUCK CORP
  • EP4597718A1 patent drawingFigure 1A~1B
  • EP4597718A1 patent drawingFigure 2
  • EP4597718A1 patent drawingFigure 3

AI summary

A battery housing (100) for holding a plurality of battery cells (102) for a vehicle, the battery housing comprising: a cell compartment (104) comprising an opening (106); a vent channel (108) fluidly connected to the cell compartment via the opening, the vent channel comprising a first outlet (110) and a second outlet (112), each of the first and second outlet being fluidly connected to an outside of the battery housing; and a thermal expansion material (114) arranged in a flow path between the opening and the first outlet, the thermal expansion material being configured to expand to prevent a flow through the first outlet at a predetermined threshold temperature.