Pouch Cell Interface Measurement Using Outer Counter Electrodes

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

It is difficult to analyze the performance of unit cells in a stack/folding type electrode assembly of secondary batteries, particularly pouch-type batteries, which are gaining popularity due to their low manufacturing cost and ease of shape deformation.

Innovation Solution

The method involves laminating counter electrodes on the outer surface of unit cells and performing interface analysis to measure performance differences, including outer and inner interfaces, using a measurement unit to assess resistance and current values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a stack/folding type electrode assembly is used to reduce manufacturing cost and improve shape flexibility, then manufacturing cost and shape adaptability are improved, but the ability to analyze and measure unit cell performance deteriorates

Engineering Contradiction:
Improvemanufacturing costVSAvoidunit cell performance analysis
Core Design Contradiction:
Ease of manufactureVSDifficulty of detecting and measuring

Solution Approach 1:

The electrode assembly is divided into multiple unit cells, each with independently measurable terminals. By segmenting the measurement capability to each unit cell level, the patent enables individual performance analysis while maintaining the cost-effective stack/folding structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Current collectors are used as intermediary elements that serve dual purposes: as structural components of the electrode assembly and as measurement terminals. These intermediaries provide accessible points for electrical connection and performance measurement without disrupting the folded structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If multiple unit cells are stacked to increase battery capacity, then energy capacity is improved, but the complexity of measuring individual unit cell performance increases

Engineering Contradiction:
Improvebattery capacityVSAvoidmeasurement system complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The measurement function is merged with the existing current collector structure. The current collectors serve both as electrical conductors for capacity accumulation and as built-in terminals for measurement, eliminating the need for separate measurement infrastructure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The current collectors perform multiple functions: they conduct electricity for charge storage, provide structural support, and serve as measurement terminals. This multi-functionality reduces overall system complexity while enabling capacity scaling across multiple unit cells.

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

This approach allows for detailed analysis of cell performance by comparing interface resistances and currents, enabling better determination of cell performance and identifying differences between cells.

Implementation Method 1

measuring a current value, and/or measuring a resistance value

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3865887B1Method for measuring cell performance
Publication Date: 2026.01.14 LG ENERGY SOLUTION LTD
  • EP3865887B1 patent drawingFigure 1
  • EP3865887B1 patent drawingFigure 2
  • EP3865887B1 patent drawingFigure 3

AI summary

The present invention relates to a method for measuring cell performance. The method for manufacturing performance of a unit cell, in which a first electrode provided with a first electrode tab, a separator, and a second electrode provided with a second electrode tab are alternately laminated to be bonded to each other, comprises an additional lamination step of further laminating counter electrodes, each of which has the same polarity as that of the second electrode and is provided with a third electrode tab, on sides facing the first electrode at the outermost sides of the unit cell with the separator therebetween, and an outer interface analysis step of measuring a different in performance between the first electrode and each of the counter electrodes by electrically connecting the first electrode tab disposed on the first electrode to the third electrode tab disposed on the counter electrode.