Battery Enclosure Venting for Thermal Runaway Gas Expansion

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Solution Overview

Problem

During thermal runaway in energy storage systems, trapped gases in battery enclosures can lead to the propagation of thermal runaway and potential fires due to flammable gas concentration exceeding the lower flammability limit.

Innovation Solution

The energy storage system includes a battery enclosure configured to couple with a conduit to another battery enclosure, allowing hot gases to expand between enclosures during thermal runaway, thereby controlling gas buildup and reducing the risk of fire.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If gas escape routes are controlled to prevent flammable gas buildup, then fire risk is reduced, but thermal runaway propagation between battery cells may be accelerated

Engineering Contradiction:

Improvefire riskVSAvoidthermal runaway propagation control

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent introduces a venting system with flame arrestors and heat-resistant materials as an intermediary between the battery cells and the external environment. This mediator allows controlled gas escape while preventing fire propagation and protecting surrounding components, thus resolving the contradiction between fire risk reduction and thermal runaway control.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs inerting strategies by introducing inert gases (such as nitrogen or carbon dioxide) into the battery enclosure to displace oxygen and create a non-flammable atmosphere. This prevents fire while allowing thermal runaway gases to vent safely, addressing the contradiction between fire prevention and thermal management.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

2Object-affected harmful factors

If flammable gas concentration is kept below lower flammability limit, then fire prevention is improved, but heat dissipation capability is reduced

Engineering Contradiction:

Improvefire preventionVSAvoidheat dissipation

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent changes the concentration parameter of flammable gases by controlling venting rates and introducing inert gases, maintaining gas composition below the lower flammability limit while preserving adequate heat dissipation through controlled venting pathways.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies different local qualities to different regions of the battery system - specific zones have enhanced venting capabilities with flame arrestors while other areas maintain sealed configurations for heat retention, allowing fire prevention without compromising overall heat dissipation.

Inventive Principle:

Principle #3Local quality

3Reliability

If venting system is designed to maximize heat dissipation, then thermal runaway propagation is reduced, but flammable gas buildup increases

Engineering Contradiction:

Improvethermal runaway propagation controlVSAvoidflammable gas concentration

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent implements continuous monitoring and active control of the venting system that adjusts venting rates based on real-time temperature and gas concentration measurements. This continuous action maintains optimal balance between heat dissipation and flammable gas concentration control, preventing both thermal runaway propagation and fire hazards.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent incorporates feedback mechanisms through sensors that monitor temperature, pressure, and gas composition, which feed back to control the venting system. This feedback loop dynamically adjusts venting to maximize heat dissipation while keeping flammable gas concentrations below dangerous thresholds.

Inventive Principle:

Principle #23Feedback

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

This solution effectively manages gas expansion during thermal runaway, minimizing oxygen ingress, maximizing heat dissipation, and providing a controlled pathway for vented gases, thus preventing the propagation of thermal runaway and reducing fire risks.

Implementation Method 1

hot gases are allowed to expand from the battery enclosure to the another battery enclosure via the conduit

Methodology Applied

Scientific EffectGas expansion: Thermal Expansion

Implementation Method 2

maximizing heat dissipation

Methodology Applied

Scientific EffectHeat dissipation: Convection

Data Source

PatentUS20250132455A1Methods and apparatus for removing gas during thermal runaway in energy storage systems

Publication Date: 2025.04.24 ENPHASE ENERGY INC

AI summary

An energy storage system is provided and comprises a battery enclosure comprising a battery module and configured to couple to a conduit for coupling to another battery enclosure of the energy storage system such that hot gases are allowed to expand from the battery enclosure to the another battery enclosure via the conduit, or vice versa, during thermal runaway.