Porous Electrode Template Formation Without Barrier Layer Pore Widening

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Solution Overview

Problem

Current methods for forming active electrode materials on three-dimensional electrode structures in solid-state batteries face challenges such as poor mechanical stability, limited energy density, and high costs due to issues with barrier layer removal and electroplating processes, particularly in large-scale manufacturing.

Innovation Solution

A method involving anodization to form porous templates with controlled channel diameters and spacings, followed by protective treatments and etching to remove barrier layers, allowing for conformal deposition of active electrode materials like manganese oxide, while maintaining mechanical stability and reducing degradation during processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the barrier layer is removed by immersing the template in H3PO4 solution, then the barrier layer is removed from channel bottoms, but excessive pore widening occurs resulting in large diameter nanowires that limit energy density

Engineering Contradiction:
Improvebarrier layer removalVSAvoidenergy density
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

A protective coating is applied to the channel walls before etching the barrier layer. This preliminary action prevents the etchant from attacking the channel walls, thereby preventing pore widening while allowing complete removal of the barrier layer from channel bottoms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The protective coating provides selective protection: the channel walls are coated and protected from etching, while the channel bottoms remain exposed for barrier layer removal. This local differentiation allows the etchant to act only where needed (at the bottoms) without causing unwanted side effects (pore widening).

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the voltage is gradually reduced during the final stage of anodization, then the barrier layer thickness is reduced to allow electroplating, but nanowires are poorly connected to the substrate through long thin root-like structures

Engineering Contradiction:
Improvebarrier layer thicknessVSAvoidmechanical stability
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The barrier layer is removed by etching after template formation, rather than attempting to control its thickness during anodization. This preliminary removal creates a clean, flat surface at the channel bottoms that provides excellent mechanical anchoring for subsequent nanowire growth, eliminating the need for thin root-like connections.

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If a three-dimensional electrode structure is used to increase surface area, then the amount of active material is increased, but conformal coating of battery materials on the three-dimensional surfaces becomes challenging

Engineering Contradiction:
Improveamount of active materialVSAvoidconformal coating
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The barrier layer is removed in advance before electroplating the active material. This creates a uniformly exposed surface at the channel bottoms that facilitates conformal deposition of the active material throughout the three-dimensional structure, including complete coverage at the previously inaccessible channel bottoms.

Inventive Principle:
Principle #10Preliminary action

4Quantity of substance

If advanced methods are used for manufacturing three-dimensional electrode structures, then the surface area is increased, but the manufacturing cost increases

Engineering Contradiction:
Improvesurface areaVSAvoidmanufacturing cost
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The problematic barrier layer is selectively removed only from the channel bottoms where it is needed, rather than removing it entirely or attempting to prevent its formation. This targeted extraction approach uses simple, low-cost etching chemistry (H3PO4 or other acids) rather than expensive advanced manufacturing techniques.

Inventive Principle:
Principle #2Taking out (Extraction)

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 method enables reproducible, conformal deposition of active electrode materials on a broad range of metals, enhancing mechanical stability, energy density, and reducing costs, making it suitable for large-scale manufacturing of solid-state batteries.

Implementation Method 1

A method is disclosed involving anodization to form porous templates with controlled channel diameters and spacings

Methodology Applied
Scientific EffectAnodization: Anodising

Implementation Method 2

followed by protective treatments and etching to remove barrier layers

Methodology Applied
Scientific EffectEtching:

Implementation Method 3

allowing for conformal deposition of active electrode materials like manganese oxide

Methodology Applied
Scientific EffectConformal deposition: Deposition (physical)

Data Source

PatentEP3655569B1Forming a layer of functional material on an electrically conductive substrate
Publication Date: 2023.11.01 INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)
  • EP3655569B1 patent drawingFigure 1
  • EP3655569B1 patent drawingFigure 2~3
  • EP3655569B1 patent drawingFigure 4~5

AI summary

Forming a layer of functional material on an electrically conductive substrate A method for forming a layer of functional material on an electrically conductive substrate is provided. This method comprises: depositing an interlayer on the substrate, depositing a functional material precursor layer on the interlayer, and activating the functional material precursor layer to thereby form the layer of functional material on the interlayer. This method may relate to the transformation of at least part of a valve metal layer into a template comprising a plurality of spaced (nano)channels, and/or to the formation of a plurality of spaced structures inside the (nano)channels of the template. The methods may further relate to the fabrication of solid-state battery cells and batteries.