Battery Pack Water Tank Release for Thermal Runaway Ignition Control

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Solution Overview

Problem

The occurrence of surface ignition and potential explosions in battery packs due to thermal runaway is a significant safety concern, as high-temperature venting gas can cause ignition on the surface of the battery pack.

Innovation Solution

A vehicle device incorporating a battery pack with a tank containing cooling or fire extinguishing water, a discharge port, and a sealing layer that melts at high temperatures to release the water, which is then sprayed onto the surface to lower the temperature and prevent ignition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional battery pack structure is used, then the battery pack can be simply constructed, but the surface temperature increases during thermal runaway causing ignition safety issues

Engineering Contradiction:
Improveignition safetyVSAvoidbattery pack structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-installing a water tank and cooling system within the battery pack structure before thermal runaway occurs. The system is prepared in advance with water stored in the tank, ready to be discharged through discharge ports when temperature sensors detect overheating conditions, thus preventing ignition before it happens.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses water as an intermediary substance to transfer heat away from the battery cells. The water tank stores this intermediary cooling agent, which is discharged onto the battery pack surface through discharge ports positioned at strategic locations, acting as a mediator between the heat source and the environment to prevent ignition.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If cooling water is discharged to lower surface temperature, then ignition can be prevented, but the device structure becomes more complex with additional components

Engineering Contradiction:
Improvesurface temperatureVSAvoidcooling system structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the cooling system with the existing battery pack structure by integrating the water tank, discharge ports, and cooling channels into the battery pack housing. This combination approach allows the cooling function to be added without requiring completely separate systems, thus limiting the increase in device complexity while achieving effective temperature reduction.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes phase transition of water (from liquid to vapor) as a cooling mechanism. When water is discharged onto the hot battery pack surface, it rapidly evaporates, absorbing large amounts of heat in the process. This phase transition provides efficient cooling to lower the surface temperature and prevent ignition.

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 implementation of a tank with cooling or fire extinguishing water effectively reduces the surface temperature of the battery pack, preventing ignition and the spread of flames, thereby enhancing safety.

Implementation Method 1

a sealing layer provided on one side surface where the tank discharge port is disposed

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

The tank includes cooling water or fire extinguishing water... which is then sprayed onto the surface to lower the temperature

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP4683034A1Vehicle device including battery pack
Publication Date: 2026.01.21 LG ENERGY SOLUTION LTD
  • EP4683034A1 patent drawingFigure 1
  • EP4683034A1 patent drawingFigure 2
  • EP4683034A1 patent drawingFigure 3

AI summary

A vehicle device according to certain aspects of the present disclosure comprises: a battery pack; and a tank. The battery pack comprises a plurality of battery cells; a pack frame in which the battery cells are directly mounted or in which the battery cells are mounted while being housed in a module frame; and a pack cover that covers the pack frame. The tank comprises a cooling water or fire extinguishing water; a tank discharge port through which cooling water or fire extinguishing water is discharged; and a sealing layer provided on one side surface where the tank discharge port is disposed.