Pouch Cell Thermal Conductivity Measurement for Anisotropic Heat Flow

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Solution Overview

Problem

Conventional thermal conductivity measurement methods are inadequate for accurately measuring the anisotropic thermal characteristics of pouch-type battery cells, which contain various materials with different properties and non-uniform arrangements.

Innovation Solution

A thermal conductivity measurement apparatus and method that includes a hot plate, guarded hot plate, measuring plates, and cooling units arranged in a symmetrical structure to measure thermal conductivity in both upward and downward directions of the battery cell, using metal materials with high thermal conductivity and heat insulating members to minimize heat loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional guarded hot plate method is used, then measurement can be performed on simple single-material test pieces, but it cannot accurately measure anisotropic thermal characteristics of pouch-type battery cells containing various materials with non-uniform arrangements

Engineering Contradiction:
Improvethermal conductivity measurement accuracyVSAvoidapplicability to complex multi-material structures
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The battery cell is divided into multiple measurement regions with different orientations (0° and 90° directions). The measurement apparatus separates the thermal conductivity measurement into distinct directional components, allowing independent measurement of thermal conductivity in different orientations of the same battery cell structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The measurement apparatus is designed to measure thermal conductivity in multiple directions using the same basic guarded hot plate structure. By rotating or repositioning the battery cell sample, the system can measure both 0° and 90° directional thermal conductivity without requiring separate specialized equipment for each orientation.

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

2Measurement precision

If heat is allowed to flow in multiple directions in the measurement apparatus, then measurement of anisotropic thermal characteristics becomes possible, but heat loss increases and measurement accuracy decreases

Engineering Contradiction:
Improveanisotropic thermal characteristic measurement accuracyVSAvoidheat loss in measurement apparatus
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

Insulation layers are introduced as intermediary materials between the heating element, battery cell sample, and cooling plate. These insulation layers prevent lateral heat loss while allowing controlled heat flow through the sample in the measurement direction, thereby reducing energy loss and improving measurement accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The measurement apparatus applies different thermal conditions to different regions: the central measurement region allows controlled heat flow through the battery cell sample, while the peripheral regions are insulated to prevent heat loss. This creates localized thermal zones that maintain measurement accuracy while minimizing overall energy loss.

Inventive Principle:
Principle #3Local quality

3Loss of energy

If the measurement apparatus is designed for single-direction heat flow, then heat loss is minimized, but it cannot measure thermal conductivity in both upward and downward directions of the battery cell

Engineering Contradiction:
Improveheat loss in measurement apparatusVSAvoidcapability to measure thermal conductivity in multiple directions
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The measurement apparatus is designed with asymmetric insulation and heating/cooling configurations that allow preferential heat flow in specific directions. By adjusting the asymmetric arrangement of insulation layers and thermal sources, the system can measure thermal conductivity in upward, downward, and lateral directions while maintaining controlled heat flow paths that minimize energy loss.

Inventive Principle:
Principle #4Asymmetry

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

Enables precise measurement of thermal conductivity in each direction of the battery cell, optimizing heat management and reducing the risk of thermal runaway by accurately determining heat transfer ratios within the cell.

Implementation Method 1

measuring the thermal conductivity by measuring the amount of heat flowing from the high temperature side to the low temperature side while accurately measuring the temperature on both sides of the sample

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

an auxiliary hot plate called a guarded hot plate is disposed around a hot plate so that heat flow can be accurately formed in one dimension in the sample

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

a cooling plate and a cooling unit are sequentially disposed at upper and lower parts in a direction perpendicular to the hot plate

Methodology Applied
Scientific EffectHeat absorption: Heat Sink

Data Source

PatentEP3855551B1Battery cell thermal conductivity measurement method
Publication Date: 2025.12.17 LG ENERGY SOLUTION LTD
  • EP3855551B1 patent drawingFigure 1
  • EP3855551B1 patent drawingFigure 2
  • EP3855551B1 patent drawingFigure 3

AI summary

The present invention relates to a device for measuring the thermal characteristics of a pouch-type battery cell, specifically, the thermal conductivity of the battery cell, and a thermal conductivity measurement method using the same. When the battery cell thermal conductivity measurement device of the present invention is used, the thermal conductivity of a pouch-type battery cell exhibiting anisotropic thermal conductivity characteristics can be separated along each direction and measured, and thereby stability according to the thermal characteristics of a product, which uses a battery cell for a rechargeable battery, can be efficiently evaluated.