Battery Module Coolant Injection to Contain Thermal Runaway

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Solution Overview

Problem

Existing battery packs fail to effectively prevent the spread of thermal runaway phenomena by rapidly lowering temperature and extinguishing flames within affected battery modules, leading to potential ignition and explosion risks.

Innovation Solution

A battery pack structure featuring a water tank, coolant tubes, sensors, and a controller to introduce coolant into affected modules, along with expansion pads to block air channels and valves or barriers to contain coolant, ensuring rapid temperature reduction and flame extinguishment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a coolant is introduced into a battery module where thermal runaway has occurred, then the temperature inside the module can be rapidly lowered to prevent flame spread, but the coolant may leak through air channels without staying inside the module

Engineering Contradiction:
Improvetemperature inside battery moduleVSAvoidcoolant containment
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The expansion pad is pre-installed in the air channel at a position that will block the channel when expanded. Before coolant injection, the pad is in a compressed state allowing air flow. When thermal runaway occurs and coolant is injected, the pad expands to block the air channel, preventing coolant leakage and ensuring the coolant stays inside the module to effectively lower the temperature.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The expansion pad changes its physical state from compressed to expanded when exposed to the thermal runaway conditions or coolant. This parameter change in volume and shape enables the pad to block the air channel, transforming the air-cooled structure into a sealed container that retains the coolant for effective cooling.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If air channels are blocked to contain coolant, then coolant can stay inside the battery module for effective cooling, but the structure becomes more complex requiring additional components

Engineering Contradiction:
Improvecoolant containmentVSAvoidcooling structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The expansion pad serves multiple functions: it acts as an air channel blocker to contain coolant, serves as a thermal barrier, and can function as a structural support element. By making the pad multi-functional, the patent avoids adding separate components for each function, thereby reducing overall structural complexity while achieving reliable coolant containment.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The expansion pad is implemented as a flexible element that can deform between compressed and expanded states. This flexible film approach allows the pad to adapt to the air channel geometry and effectively block coolant leakage paths without requiring rigid, complex sealing structures.

Inventive Principle:
Principle #30Flexible shells and thin films

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 the spread of thermal runaway by quickly cooling and containing flames within affected modules, minimizing the risk of ignition and explosion.

Implementation Method 1

a coolant tube (150) configured to introduce the coolant into the battery module

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a plurality of supply tubes (152) respectively connecting the battery modules and the main tube to each other

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

an expansion pad (126) disposed inside the air inlet (124) and the air outlet (125) and configured to expand due to the contact with a coolant introduced into the battery module to close the air inlet and the air outlet

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4027435B1Battery pack having structure allowing input of cooling water into battery module upon occurrence of thermal runaway phenomenon and energy storage system comprising same
Publication Date: 2026.03.04 LG ENERGY SOLUTION LTD
  • EP4027435B1 patent drawingFigure 1
  • EP4027435B1 patent drawingFigure 2~3
  • EP4027435B1 patent drawingFigure 4~5

AI summary

A battery pack includes a pack housing; a plurality of battery modules stacked in the pack housing; a water tank connected to the plurality of battery modules and configured to store a coolant; a coolant tube including a main tube connected to the water tank, a plurality of supply tubes configured to connect the main tube and the battery modules to each other, and a bypass tube connected to the main tube at a point above a supply tube located at a top end among the plurality of supply tubes and at a point below a supply tube located at a bottom end; at least one sensor installed in the pack housing to detect a thermal runaway phenomenon generated in at least a part of the plurality of battery modules; and a controller configured to output a control signal for introducing a coolant into the battery module through the coolant tube when a thermal runaway phenomenon is detected by the sensor.