Cross-woven Z-fold Electrode Assembly for High Volumetric Efficiency

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Solution Overview

Problem

Current electrode assemblies for energy storage devices, such as battery cells, face challenges in achieving high volumetric efficiency while maintaining low manufacturing costs and avoiding defects, particularly with z-folded configurations that have limited energy production capacity due to single-sided active material application.

Innovation Solution

A cross-woven z-fold electrode assembly is developed, where positive and negative electrodes are interwoven with each other, with one electrode disposed between separators to form an alpha electrode and the other forming a beta electrode, both arranged in series of z-folds that alternate along a stack axis, allowing for active material on both sides of the substrates and continuous manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If z-folded electrode assembly with single-sided active material application is used, then manufacturing cost is reduced and manufacturing simplicity is improved, but energy production capacity is limited

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidenergy production capacity
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent transitions from single-sided to double-sided active material application by utilizing both sides of the electrode substrate. This dimensional change in material utilization doubles the energy production capacity while preserving the z-folded configuration's manufacturing advantages.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent combines the manufacturing simplicity of z-folded single-sided electrodes with the enhanced capacity of double-sided active material application. By merging these approaches, the invention achieves both ease of manufacture and high energy production capacity.

Inventive Principle:
Principle #5Merging (Combining)

2Volume of stationary object

If stacked arrangement of individual electrode plates is used, then volumetric efficiency is improved, but manufacturing complexity increases and manufacturing cost increases

Engineering Contradiction:
Improvevolumetric efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
Volume of stationary objectVSDevice complexity

Solution Approach 1:

The patent segments the electrode assembly into z-folded units with alternating positive and negative electrodes. This segmentation allows the assembly to achieve high volumetric efficiency similar to stacked arrangements while maintaining the manufacturing simplicity of continuous z-folded construction.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If jelly-roll electrode assembly is used, then manufacturing simplicity is improved, but volumetric efficiency is limited

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidvolumetric efficiency
Core Design Contradiction:
Ease of manufactureVSVolume of stationary object

Solution Approach 1:

The patent changes the spatial arrangement from the rolled jelly-roll configuration to a z-folded stacked configuration. This dimensional change enables higher volumetric efficiency by eliminating the empty spaces and separator requirements of jelly-roll designs, while maintaining manufacturing simplicity through continuous folding processes.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3381078B1Cross-woven electrode assembly
Publication Date: 2020.04.01 ROBERT BOSCH GMBH
  • EP3381078B1 patent drawingFigure 1~2
  • EP3381078B1 patent drawingFigure 3~4
  • EP3381078B1 patent drawingFigure 5~6

AI summary

A electrode assembly includes an electrode pair having a positive electrode and a negative electrode that are arranged crosswise and each z-folded while being cross-woven together in a continuous manner. The electrode assembly includes an electrode stack in which portions of the positive electrode are stacked along a stack axis so as to alternate with portions of the negative electrode.