Standing Wave Fluidization for Ultrafine Particle Coating
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Solution Overview
Problem
Existing methods for coating ultra-fine particles less than 20 microns in diameter are inefficient, leading to non-uniform coatings and increased energy consumption due to the need for repetitive equipment motion, which results in suboptimal ion and electron transport in electrochemical applications like lithium ion batteries, causing degradation and reducing recharge capacity.
Innovation Solution
A method utilizing standing waves to homogeneously disperse and fluidize ultra-fine particles within a reaction chamber, allowing for conformal coatings via atomic layer deposition, ensuring uniformity and precise control over coating thickness, thereby preventing unwanted reactions and maintaining recharging capacities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional coating techniques (sol-gel, chemical vapor deposition) are used on ultra-fine particles, then coating can be applied to flat or large particles, but uniformity and layer thickness control are poor
Solution Approach 1:
The patent applies ultrasonic vibration to the substrate during coating deposition. The ultrasonic waves create mechanical oscillation that prevents particle agglomeration and ensures uniform distribution of coating material across the substrate surface, thereby achieving precise control over coating uniformity and layer thickness while being applicable to ultra-fine particles
Solution Approach 2:
The patent changes the physical state and parameters of the coating process by using ultrasonic frequency vibration (typically 20-100 kHz) to alter how coating material deposits on particles. This parameter change enables conformal coating on ultra-fine particles with controlled thickness and uniformity, resolving the contradiction between manufacturing precision and adaptability to different particle sizes
2Manufacturing precision
If repetitive equipment motion is used for coating ultra-fine particles, then coating process can be performed, but energy consumption increases and coating uniformity decreases
Solution Approach 1:
The patent replaces repetitive mechanical equipment motion with ultrasonic vibration fields. Instead of mechanically moving the coating head or substrate back and forth, ultrasonic waves are used to create oscillatory motion at the molecular level, which achieves uniform coating distribution without the high energy consumption associated with macroscopic mechanical motion
Solution Approach 2:
Ultrasonic vibration provides continuous micro-scale oscillation that maintains uniform coating deposition without requiring large-scale mechanical movement. This vibration-based approach consumes significantly less energy while achieving superior coating uniformity compared to conventional repetitive mechanical motion systems
3Productivity
If high surface area materials are used as reaction surfaces, then catalytic efficiency increases, but electrode and electrolyte degradation occurs
Solution Approach 1:
The patent applies conformal coating that creates a localized protective layer on the high surface area catalyst particles. This coating provides different properties at different locations: the core catalyst material maintains high surface area for catalytic efficiency, while the surface coating provides protection against degradation, thus achieving both high productivity and reliability
Solution Approach 2:
The patent creates composite structures where catalyst particles are coated with protective materials to form core-shell composite particles. The core maintains high surface area for catalytic activity, while the shell provides protection against electrode and electrolyte degradation, simultaneously achieving high catalytic efficiency and system reliability
4Productivity
If particle size is reduced to micro- or nano-scale, then reaction surface value increases, but coating uniformity and thickness control become difficult
Solution Approach 1:
The patent uses ultrasonic vibration to counteract the strong inter-particle forces (van der Waals and electrostatic forces) that cause agglomeration of ultra-fine particles. The mechanical vibration energy keeps particles dispersed and prevents clustering, enabling uniform coating deposition and precise thickness control on particles with diameters less than 20 micrometers
Solution Approach 2:
The patent employs periodic ultrasonic oscillation to continuously disrupt particle agglomeration during the coating process. This periodic action maintains particles in a dispersed state throughout the coating deposition, ensuring that each particle receives uniform coating coverage and achieving precise thickness control on high-value ultra-fine reaction surfaces
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 method achieves a 2 to 8 fold increase in Li ion transport across the electrode-electrolyte interface, prevents Mn ion migration, and maintains recharging capacities by ensuring conformal, pin-hole free coatings with controlled thickness, enhancing the stability and performance of electrochemical devices.
Implementation Method 1
A method utilizing standing waves to homogeneously disperse and fluidize ultra-fine particles within a reaction chamber
Implementation Method 2
allowing for conformal coatings via atomic layer deposition, ensuring uniformity and precise control over coating thickness
Implementation Method 3
allowing for conformal coatings via atomic layer deposition, ensuring uniformity and precise control over coating thickness
Implementation Method 4
The method achieves a 2 to 8 fold increase in Li ion transport across the electrode-electrolyte interface, prevents Mn ion migration
Data Source
AI summary
The invention provides a method for dispersing particles within a reaction field, the method comprising confining the particles to the reaction field using a standing wave. The invention also provides a system for coating particles, the system comprising a reaction zone; a means for producing fluidized particles within the reaction zone; a fluid to produce a standing wave within the reaction zone; and a means for introducing coating moieties to the reaction zone. The invention also provides a method for coating particles, the method comprising fluidizing the particles, subjecting the particles to a standing wave; and contacting the subjected particles with a coating moiety.