Expandable Battery Module Venting for Thermal Event Containment

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Solution Overview

Problem

Secondary batteries are vulnerable to thermal events, which can lead to uncontrolled gas, flame, and heat generation, potentially causing fires or explosions, especially in concentrated battery modules used in electric vehicles, posing risks to safety and property.

Innovation Solution

A battery module with a module case featuring a top plate with high expansibility compared to other components, equipped with a venting hole and a module valve that opens at specific pressure or temperature levels, allowing controlled expansion and venting to manage thermal events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple battery cells are concentrated in a narrow space to increase output and capacity, then productivity and energy density are improved, but the risk of thermal events and thermal propagation increases

Engineering Contradiction:

Improveoutput and capacityVSAvoidthermal event risk and thermal propagation

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The battery module is divided into multiple battery cell groups, with each group independently accommodated in separate module cases. This segmentation isolates thermal events to specific groups, preventing thermal propagation across the entire battery system while maintaining high density through compact arrangement of multiple segmented units.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A partition wall is introduced as an intermediary structure between adjacent battery cell groups. This partition wall acts as a thermal barrier that physically separates battery cells, blocking heat transfer and preventing thermal runaway propagation while allowing the module to maintain high cell density for improved productivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If a rigid sealed structure is used to protect battery cells, then strength and reliability are improved, but the ability to buffer thermal expansion and control gas venting is reduced

Engineering Contradiction:

Improvestructural protectionVSAvoidthermal expansion buffering and gas venting control

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The module case incorporates a flexible top plate that can dynamically expand and deform in response to internal pressure changes during thermal events. This dynamic structure maintains structural integrity while adapting to thermal conditions, allowing controlled gas venting through expansion without compromising the overall strength and protection of the module.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The top plate of the module case is designed as a flexible component rather than a rigid seal. This flexible shell can expand outward to buffer thermal expansion of battery cells and provide controlled gas venting pathways, while the surrounding rigid structure maintains overall strength and protection against external damage.

Inventive Principle:

Principle #30Flexible shells and thin films

3Reliability

If thermal insulation is enhanced to prevent thermal propagation, then safety is improved, but heat dissipation during normal operation may be reduced

Engineering Contradiction:

Improvethermal propagation preventionVSAvoidheat dissipation efficiency

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The battery module uses segmented construction with partition walls creating independent thermal zones. During normal operation, each segment can dissipate heat independently through its own surface area, maintaining efficient heat dissipation. During thermal events, these same partitions act as insulation barriers to prevent thermal propagation to adjacent segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the module case have different thermal properties. The partition walls and top plate provide enhanced thermal insulation locally at critical interfaces between battery cell groups to prevent thermal propagation, while the overall structure maintains pathways for heat dissipation during normal operation through controlled ventilation and surface area exposure.

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 solution effectively buffers and controls gas and heat, reducing the risk of explosions and thermal chain reactions, providing time for evacuation and minimizing damage to adjacent modules and components.

Implementation Method 1

a top plate, a base plate and a side plate to define an inner space and to accommodate the cell assembly in the inner space, the top plate being configured to at least partially have high expansibility compared to at least one of the base plate and the side plate

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4354617B1Battery module with reinforced safety

Publication Date: 2026.02.18 LG ENERGY SOLUTION LTD

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AI summary

Disclosed is a battery module with an improved structure to improve safety. The battery module includes a cell assembly having at least one battery cell; and a module case configured to have a top plate, a base plate and a side plate to define an inner space and to accommodate the cell assembly in the inner space, the top plate being configured to at least partially have high expansibility compared to at least one of the base plate and the side plate.