Titanium Nanotube Electrode Anodization for Battery Anodes

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Solution Overview

Problem

Existing lithium-ion batteries face limitations with graphite anodes due to low energy density, volumetric expansion, and limited cycle life, while alternative materials like silicon and titanium dioxide suffer from high cost and poor Li-ion transport kinetics.

Innovation Solution

A method for preparing titanium nanotube electrodes through pre-treating a titanium substrate with acid pickling and anodization to form nanotubes, followed by electrodepositing Group IVA elements, creating a self-supported metal oxide nanoarray electrode without binders or conductive additives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If graphite is used as anode material, then the battery can be manufactured with existing processes, but the energy density is low and volumetric expansion occurs

Engineering Contradiction:
ImprovemanufacturabilityVSAvoidenergy density
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The invention changes the material parameter from graphite to titanium nanotubes, fundamentally altering the anode material's properties to achieve higher energy density while maintaining manufacturability through a systematic preparation process involving pickling, anodization, and electrodepositing

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure by electrodepositing conductive additives and binder materials onto the titanium nanotube surface, forming a multi-component anode material that combines the high energy density of titanium with the electrical conductivity and mechanical integrity provided by the composite layers

Inventive Principle:
Principle #40Composite materials

2Duration of action of moving object

If graphite anode is used continuously, then the battery operates over time, but volumetric expansion of up to 50% occurs

Engineering Contradiction:
Improvecontinuous usageVSAvoidvolumetric expansion
Core Design Contradiction:
Duration of action of moving objectVSVolume of moving object

Solution Approach 1:

The invention changes the material parameter from graphite to titanium nanotubes, which have a different crystal structure and ion insertion mechanism that prevents the significant volumetric expansion observed in graphite during continuous charging and discharging cycles

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If titanium dioxide is used as anode material, then no volumetric expansion occurs, but energy density is low and lifespan is limited

Engineering Contradiction:
Improvevolumetric stabilityVSAvoidenergy density
Core Design Contradiction:
Volume of moving objectVSQuantity of substance

Solution Approach 1:

The invention segments the bulk titanium dioxide material into nanoscale tubular structures with diameters of 50-200 nm, creating a high surface area to volume ratio that enhances lithium ion transport kinetics and allows for higher capacity while maintaining the volumetric stability of titanium dioxide

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the structural parameter of titanium dioxide from bulk form to nanotube form, fundamentally altering the material's properties to improve energy density and lifespan while preserving the volumetric stability characteristic of titanium-based anodes

Inventive Principle:
Principle #35Parameter changes

4Device complexity

If bulk metal oxides are used, then the structure is simple, but Li-ion transport kinetics are poor

Engineering Contradiction:
Improvestructural simplicityVSAvoidLi-ion transport kinetics
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The invention segments the bulk metal oxide into nanoscale tubular structures, creating numerous narrow channels that facilitate rapid lithium ion diffusion throughout the material, dramatically improving transport kinetics while maintaining a relatively simple overall electrode structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from three-dimensional bulk material to one-dimensional nanotube structures, creating direct pathways for lithium ion transport along the tube length and significantly enhancing ion mobility compared to isotropic bulk materials

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

5Speed

If titanium nanotubes with diameter less than 50nm are prepared, then charge transfer efficiency is enhanced, but the preparation process becomes more complex

Engineering Contradiction:
Improvecharge transfer efficiencyVSAvoidpreparation process complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The invention optimizes the anodization parameters including voltage (10-30V), time (1-24 hours), and electrolyte composition to precisely control the nanotube diameter and morphology, achieving the desired 50-200 nm diameter range that balances charge transfer efficiency with preparational feasibility

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The anodization process is a self-organizing electrochemical process that automatically forms uniform nanotube arrays with controlled dimensions based on the applied voltage and time parameters, eliminating the need for complex top-down fabrication methods and simplifying the overall preparation process

Inventive Principle:
Principle #25Self-service

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 titanium nanotube electrodes enhance charge transfer efficiency, improve gravimetric capacity, and offer high capacity, high-rate capability, and long cycle life, addressing the limitations of existing anode materials by providing fast electron transport and alleviating volume expansion.

Implementation Method 1

pre-treating a titanium substrate at least by pickling in an acid at a temperature ranging between 40°C to 80°C

Methodology Applied
Scientific EffectAcid pickling: Chemical Bonding

Implementation Method 2

subjecting the pre-treated titanium substrate to anodization at a voltage ranging between 10V to 30V to obtain titanium nanotubes having diameter less than 50nm

Methodology Applied
Scientific EffectAnodization: Anodising

Implementation Method 3

subjecting the pre-treated titanium substrate to anodization at a voltage ranging between 10V to 30V to obtain titanium nanotubes

Methodology Applied
Scientific EffectElectrochemical oxidation: Oxidation

Implementation Method 4

electrodepositing one or more Group IVA element on the titanium nanotubes to obtain the titanium nanotube electrode

Methodology Applied
Scientific EffectElectrodeposition: Electrodeposition

Data Source

PatentEP4063539A1A method for preparing a titanium nanotube electrode
Publication Date: 2022.09.28 TVS MOTOR CO LTD
  • EP4063539A1 patent drawingFigure 1
  • EP4063539A1 patent drawingFigure 2
  • EP4063539A1 patent drawingFigure 3

AI summary

The present invention is directed to a method for preparing a titanium nanotube electrode. The method includes the steps of: pre-treating a titanium substrate at least by pickling in an acid at a temperature ranging between 40°C to 80°C; subjecting the pre-treated titanium substrate to anodization at a voltage ranging between 10V to 30V to obtain titanium nanotubes having diameter less than 50nm; and electrodepositing one or more Group IVA element on the titanium nanotubes to obtain the titanium nanotube electrode.