Battery Module Cover Assembly for Thermal Runaway Venting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing battery modules are prone to structural collapse and fire propagation during thermal runaway, which can lead to the spread of gas or flame to adjacent cells, posing a significant safety risk.

Innovation Solution

A cover assembly for battery modules featuring a flame-retardant cover with protruding portions inserted into venting holes of a metallic cover frame, designed to prevent the frame from melting or collapsing under high-temperature/high-pressure conditions, thereby delaying or preventing flame propagation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional battery module cover frame is used, then the structure is simple and easy to manufacture, but the frame collapses under high-temperature or high-pressure environments during thermal runaway, allowing fire propagation

Engineering Contradiction:
Improveresistance to collapse during thermal runawayVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining a metallic cover frame with a flame-retardant cover made of heat-resistant material. This composite structure prevents the frame from collapsing during thermal runaway while maintaining manufacturing feasibility. The flame-retardant cover acts as a protective layer that enhances the overall reliability without significantly complicating the manufacturing process.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The flame-retardant cover is disposed between the cover frame and the battery cells, creating a nested structure where the inner cover is protected by the outer frame. This nesting approach enhances safety by adding a protective layer without requiring a completely redesign of the overall structure, thus improving reliability while controlling complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Object-generated harmful factors

If venting holes are provided in the cover frame, then gas can be discharged during thermal runaway, but flame may propagate through the holes to adjacent cells

Engineering Contradiction:
Improvegas discharge capabilityVSAvoidflame propagation risk
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The flame-retardant cover serves as an intermediary element between the venting holes and the battery cells. It allows gas to pass through while blocking flame propagation, thus resolving the contradiction between gas discharge capability and flame propagation prevention. The intermediary material properties are specifically chosen to permit gas permeability while providing fire resistance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The flame-retardant cover provides localized protection at the venting hole areas where flame propagation risk is highest. By applying the flame-retardant material specifically at these critical locations rather than uniformly across the entire structure, the solution addresses the harmful factors locally while maintaining overall structural simplicity and manufacturing ease.

Inventive Principle:
Principle #3Local quality

3Strength

If the cover frame is made of thick material to prevent collapse, then structural strength is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvecover frame strengthVSAvoidmanufacturing ease
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

Instead of increasing the thickness of the metallic cover frame, the patent uses a composite structure where a flame-retardant cover is added as a separate layer. This approach achieves the desired strength and collapse resistance without modifying the original frame dimensions, thereby maintaining manufacturing ease and avoiding increased complexity or cost associated with thicker materials.

Inventive Principle:
Principle #40Composite materials

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 cover assembly effectively prevents the collapse of the cover frame and minimizes the spread of gas or flame to adjacent battery modules or cells, enhancing safety by ensuring stable discharge of thermal runaway gases and flames.

Implementation Method 1

a flame-retardant cover disposed between the cover frame and the battery cells, coupled to one surface of the cover frame

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

flame-retardant cover... having a plurality of protruding portions inserted into the venting holes of the cover frame

Methodology Applied
Scientific EffectFire resistance: Refractory Material

Implementation Method 3

the cover assembly being capable of improving safety by smoothly discharging gas or flame by preventing a cover of a battery module from collapsing

Methodology Applied
Scientific EffectPressure-driven flow: Pressure Gradient

Data Source

PatentEP4693683A1Cover assembly of battery module, battery pack, and vehicle comprising same
Publication Date: 2026.02.11 LG ENERGY SOLUTION LTD
  • EP4693683A1 patent drawingFigure 1
  • EP4693683A1 patent drawingFigure 2~3
  • EP4693683A1 patent drawingFigure 4~5

AI summary

Disclosed is a cover assembly for a battery module, a battery pack, and a vehicle including the same, the cover assembly including a cover frame coupled to one opened side of a battery module casing in which a plurality of battery cells is embedded, the cover frame being configured to close the battery module casing and having a plurality of venting holes, and a flame-retardant cover disposed between the cover frame and the battery cells, coupled to one surface of the cover frame, and having a plurality of protruding portions inserted into the venting holes of the cover frame.