Battery Module Case Coating and Venting for Thermal Runaway Isolation

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Solution Overview

Problem

Battery modules are prone to thermal runaway, leading to heat accumulation and propagation, which can cause fires or explosions, and there is a need for structures that prevent heat accumulation and minimize thermal conduction and radiation between modules.

Innovation Solution

A battery module design featuring a protective layer made of materials like polyurethane or silicone on the module case, venting holes for gas release, and a top cover with improved adhesion using an adhesive member and primer layer to manage thermal events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If battery cells are densely packed in a module case to increase energy density, then the charge/discharge capacity increases, but thermal runaway can propagate rapidly to adjacent cells causing safety hazards

Engineering Contradiction:
Improvecharge/discharge capacityVSAvoidthermal runaway propagation
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The module case is divided into multiple compartments by partition walls, separating battery cells into isolated groups. This segmentation prevents thermal runaway from propagating between cells by creating physical barriers that block heat transfer and flame spread, while still allowing dense packing within each compartment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Heat-resistant coating layers are applied to the module case and partition walls to serve as intermediary protective barriers. These coatings have low thermal conductivity and high heat resistance, blocking thermal conduction from the battery cells to the metal case and preventing ignition of adjacent cells.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If a metal module case with high thermal conductivity is used, then structural strength and heat dissipation improve, but thermal conduction during thermal events causes rapid heat spread to adjacent modules

Engineering Contradiction:
Improvestructural strengthVSAvoidthermal conduction
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

Heat-resistant coating layers are applied to the metal module case to serve as intermediary barriers. These coatings have low thermal conductivity, blocking the direct thermal conduction path from battery cells through the metal case to adjacent modules, while the metal case maintains its structural strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The module case is designed as a composite structure combining metal substrate with heat-resistant coating layers. The metal provides structural strength and rigidity, while the coating layers provide thermal insulation properties, creating a multi-functional composite structure that addresses both strength and thermal conduction issues.

Inventive Principle:
Principle #40Composite materials

3Object-generated harmful factors

If venting holes are added to the module case to release gases, then gas accumulation during thermal events is prevented, but the protective layer must be applied to complex geometries including hole interiors increasing manufacturing difficulty

Engineering Contradiction:
Improvegas accumulationVSAvoidprotective layer application
Core Design Contradiction:
Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The venting holes are designed with specific dimensional parameters including diameter, depth, and spacing optimized for gas release efficiency. The protective coating is applied to these holes with controlled thickness parameters, balancing the need for gas venting with the requirement for thermal protection while considering manufacturing constraints.

Inventive Principle:
Principle #35Parameter changes

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 design effectively prevents heat accumulation and thermal runaway propagation, ensuring safety and reliability by minimizing thermal conduction and radiation between modules.

Implementation Method 1

a protective layer disposed on an outer surface of the module case and configured to prevent thermal conduction and thermal radiation to an outside of the module case

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a protective layer disposed on an outer surface of the module case and configured to prevent thermal conduction and thermal radiation to an outside of the module case

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 3

the module case may have at least one venting hole in an upper surface, wherein gas from the battery cell may be vented through the venting hole

Methodology Applied
Scientific EffectGas venting:

Data Source

PatentEP4645532A1Battery module, and battery pack and vehicle including same
Publication Date: 2025.11.05 LG ENERGY SOLUTION LTD
  • EP4645532A1 patent drawingFigure 1
  • EP4645532A1 patent drawingFigure 2
  • EP4645532A1 patent drawingFigure 3

AI summary

The present disclosure relates to a battery module including a cell stack including a plurality of battery cells; a module case configured to accommodate the cell stack; and a protective layer disposed on an outer surface of the module case and configured to prevent thermal conduction and thermal radiation to an outside of the module case.