Z-Folded Electrode Assembly With Laminated Outer Stacks

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Solution Overview

Problem

Existing electrode assembly manufacturing methods face challenges in achieving a stable structure with a positive electrode size larger than the negative electrode, leading to reduced capacity and increased risk of degradation and short circuits due to high process tolerances.

Innovation Solution

An electrode assembly design that alternately stacks positive and negative electrodes with separators, utilizing a Z-folding method for increased positive electrode size and a lamination & stacking method for stability, with single-sided electrodes and varying separator thicknesses to minimize degradation and short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the lamination & stacking method is used to bond electrodes and separators, then the electrode assembly has superior durability and stability, but the number of processes increases and allowable tolerances are reduced

Engineering Contradiction:
ImprovedurabilityVSAvoidnumber of processes
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electrode assembly is divided into multiple unit cells, each independently manufactured through lamination & stacking. This segmentation allows each unit cell to maintain high reliability through bonding while the overall assembly benefits from modular construction, reducing the cumulative impact of multiple processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electrodes and separators are pre-bonded together in unit cells before final assembly. This preliminary bonding action ensures proper alignment and reduces tolerance accumulation in the final stacking process, maintaining durability while streamlining the overall manufacturing sequence.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the lamination & stacking method is used with multiple processes, then bonding is improved, but allowable tolerances are reduced leading to smaller positive electrode size

Engineering Contradiction:
Improvebonding precisionVSAvoidpositive electrode size
Core Design Contradiction:
Manufacturing precisionVSArea of moving object

Solution Approach 1:

The electrode assembly is divided into multiple unit cells, each independently manufactured through lamination & stacking. This segmentation allows each unit cell to maintain high reliability through bonding while the overall assembly benefits from modular construction, reducing the cumulative impact of multiple processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electrodes and separators are pre-bonded together in unit cells before final assembly. This preliminary bonding action ensures proper alignment and reduces tolerance accumulation in the final stacking process, maintaining durability while streamlining the overall manufacturing sequence.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the Z-folding method is used to reduce processes, then production rate increases, but the positive electrode size becomes larger than negative electrode leading to degradation risk

Engineering Contradiction:
Improveproduction rateVSAvoidelectrode stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The electrode assembly is divided into multiple unit cells, each independently manufactured through lamination & stacking. This segmentation allows each unit cell to maintain high reliability through bonding while the overall assembly benefits from modular construction, reducing the cumulative impact of multiple processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electrodes and separators are pre-bonded together in unit cells before final assembly. This preliminary bonding action ensures proper alignment and reduces tolerance accumulation in the final stacking process, maintaining durability while streamlining the overall manufacturing sequence.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If the Z-folding method is used with fewer processes, then production efficiency improves, but allowable tolerance accumulation increases

Engineering Contradiction:
Improveproduction efficiencyVSAvoidallowable tolerance
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The electrode assembly is divided into multiple unit cells, each independently manufactured through lamination & stacking. This segmentation allows each unit cell to maintain high reliability through bonding while the overall assembly benefits from modular construction, reducing the cumulative impact of multiple processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electrodes and separators are pre-bonded together in unit cells before final assembly. This preliminary bonding action ensures proper alignment and reduces tolerance accumulation in the final stacking process, maintaining durability while streamlining the overall manufacturing sequence.

Inventive Principle:
Principle #10Preliminary action

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 enhances positive electrode capacity while improving stability and reducing the risk of degradation and short circuits by optimizing the positive electrode size and incorporating a Z-folding structure with a lamination & stacking method.

Implementation Method 1

a folding unit in which a positive electrode unit and a negative electrode unit are alternately inserted between layers of a separator of which one side and the other side are alternately folded in a zigzag shape

Methodology Applied
Scientific EffectZ-folding: Folding

Implementation Method 2

While passing through the laminating device, heat and a pressure may be applied between the positive electrode 1, the separator 3, the negative electrode 2, and the separator 3 to bond the positive electrode 1, the separator 3, the negative electrode 2, and the separator 3 to each other

Methodology Applied
Scientific EffectLamination: Lamination

Data Source

PatentEP3712997B1Electrode assembly
Publication Date: 2025.08.27 LG ENERGY SOLUTION LTD
  • EP3712997B1 patent drawingFigure 1A
  • EP3712997B1 patent drawingFigure 1B
  • EP3712997B1 patent drawingFigure 2

AI summary

An electrode assembly in which a positive electrode and a negative electrode are alternately stacked, and a separator is disposed between the positive electrode and the negative electrode according to the present invention comprises: a folding unit a negative electrode unit and a positive electrode unit are alternately inserted between layers of the separator of which one side and the other side are alternately folded in a zigzag shape in a direction perpendicular to a direction in which the positive electrode and the negative electrode are stacked; and a stacking unit in which the positive electrode, the separator, and the negative electrode, each of which is cut by a predetermined size, are sequentially stacked, wherein the negative electrode is disposed at the outermost layer of the negative electrode unit, and the positive electrode is disposed at the outermost layer of the positive electrode unit, and the stacking unit is stacked on each of the uppermost layer and the lowermost layer of the folding unit. According to the present invention having the above-described configuration, the folding unit having a Z-folding structure and the stacking unit having a lamination & stacking structure may be bonded to each other. Thus, the positive electrode may increase in area relative to the negative electrode in the folding unit to increase in capacity, and the stacking unit may be disposed on the outermost layer of the folding unit to improve stability.