Pouch Cell Cover Venting and Particle Capture for Thermal Runaway

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Solution Overview

Problem

Conventional battery packs face issues with thermal event propagation between battery cells, leading to potential ignition or explosion, and there is a need for a configuration that can control thermal events effectively.

Innovation Solution

A battery cell unit with a cell cover featuring a mesh member, directional venting unit, and thermal resin to guide venting gas in a specific direction, along with a particle pocket to collect high-temperature particles, preventing flame and gas propagation to adjacent cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If pouch-type batteries are used for light weight and small dead space, then weight and space efficiency are improved, but vulnerability to external impact and poor assemblability worsen

Engineering Contradiction:
Improvebattery weightVSAvoidimpact resistance
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The battery pack is divided into modular battery cell units, each containing a pouch-type battery cell and protective structures. This segmentation allows the lightweight pouch design to be combined with protective elements at the module level, resolving the contradiction between weight reduction and impact resistance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cell cover is constructed as a composite structure combining metal mesh members with porous metal plates, creating a multi-layer protective barrier that maintains the lightweight advantage of pouch batteries while adding impact resistance through the composite cell cover structure.

Inventive Principle:
Principle #40Composite materials

2Reliability

If thermal event suppression measures are added to prevent propagation between battery cells, then safety is improved, but device complexity increases

Engineering Contradiction:
Improvethermal safetyVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The harmful thermal event propagation is extracted and redirected through the directional venting unit. Instead of adding complex active suppression systems, the design passively channels venting gas and thermal events in a controlled direction away from adjacent cells, maintaining safety while minimizing structural complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cell cover acts as an intermediary structure between battery cells, providing physical separation and controlled venting pathways. This intermediary structure prevents direct thermal propagation while maintaining a relatively simple overall design compared to active suppression systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a cell cover structure is added to control thermal events and prevent flame propagation, then thermal safety is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvethermal event controlVSAvoidassembly difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The cell cover is designed as a segmented modular component that can be separately manufactured and then assembled to the battery cell. This segmentation allows for specialized manufacturing of the mesh and porous plate components independently, improving ease of manufacture while maintaining thermal event control capabilities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cell cover structure serves multiple functions simultaneously: it provides thermal event control, flame propagation prevention, and structural support. This multi-functionality reduces the need for additional separate components, thereby simplifying the overall manufacturing process despite the enhanced safety features.

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

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 thermal runaway propagation by discharging venting gas and collecting high-temperature particles, maintaining cell assembly integrity and enhancing cooling efficiency.

Implementation Method 1

a mesh member may be formed inside the particle pocket portion

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

a directional venting unit may be formed in the cell cover, the directional venting unit may include a gas outlet formed in the portion of the cell cover to which the thermal resin is not coupled, and a movement path formed between the pouch-type battery cell and the cell cover

Methodology Applied
Scientific EffectGas flow direction control:

Implementation Method 3

the battery cell unit may include a thermal resin coupled to the cell cover

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4407774B1Battery cell unit, and battery pack and vehicle including the same
Publication Date: 2026.03.04 LG ENERGY SOLUTION LTD
  • EP4407774B1 patent drawingFigure 1
  • EP4407774B1 patent drawingFigure 2
  • EP4407774B1 patent drawingFigure 3

AI summary

Provided are a battery cell unit, and a battery pack and a vehicle including the same. A battery cell unit according to an embodiment of the present disclosure includes a pouch-type battery cell, and a cell cover provided to at least partially surround the pouch-type battery cell, wherein the cell cover is configured to be spaced apart from the pouch-type battery cell and includes a particle pocket portion configured to collect particles ejected from the pouch-type battery cell when a thermal event occurs.