Liquid-Phase Thin-Film Coating for Porous Battery Electrodes
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Solution Overview
Problem
Current methods for depositing conformal coatings on battery electrodes, such as traditional vapor phase atomic layer deposition (ALD), face challenges including high substrate temperatures, inefficient radiative heating, poor materials utilization, and increased internal resistance due to passivating layers, which hinder the production of high-quality, uniform films on porous substrates like lithium-ion battery electrodes.
Innovation Solution
A liquid-phase deposition method is introduced, where battery electrodes are conveyed through a series of reaction chambers containing different liquid solutions, allowing reagents to adsorb and react, forming a thin film with precise control over thickness and conformality, utilizing solvation energy instead of high-temperature thermal evaporation, and incorporating rinsing and filtration steps to recover and recycle reagents and solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional vapor phase ALD is used to deposit conformal coatings on battery electrodes, then film conformality and uniformity are improved, but substrate temperature must be maintained above precursor boiling point (>100°C to >200°C) which causes polymer binder degradation
Solution Approach 1:
The patent transitions from vapor-phase to liquid-phase deposition, utilizing the liquid phase instead of vapor phase to deliver metalorganic precursors. This phase change allows deposition at lower temperatures compatible with polymer binders while maintaining conformal coating quality through liquid-phase surface mobility mechanisms
Solution Approach 2:
The invention changes the temperature parameter from >100°C to <100°C by switching from vapor-phase to liquid-phase ALD. This parameter change enables the use of lower temperatures that prevent polymer binder degradation while still achieving conformal coatings through modified deposition chemistry in liquid phase
2Manufacturing precision
If traditional vapor phase ALD is used, then conformal coatings are achieved, but radiative heating is inefficient for reflective foil substrates and materials utilization is poor due to continuous purge and evacuation
Solution Approach 1:
The patent replaces the vacuum-based vapor delivery system with a liquid-phase delivery system using pumps and fluid flow. Liquid-phase ALD uses hydraulic principles to deliver precursors through liquid solutions, eliminating the need for vacuum pumping and radiative heating, thereby improving energy efficiency and materials utilization
Solution Approach 2:
The invention substitutes the mechanical vacuum evacuation system with a liquid flow-based system. Instead of using vacuum pumps to remove excess precursor and maintain pressure differentials, the liquid-phase process uses solution flow and filtration to achieve the same purpose with significantly lower energy consumption
3Reliability
If passivating layers are deposited to reduce SEI formation, then side reactions are inhibited, but internal resistance increases due to electron transfer blockage
Solution Approach 1:
The patent applies local quality by creating non-uniform coating thickness or composition across different regions of the electrode. The conformal coating provides protective functionality at the electrode-electrolyte interface while maintaining electron transfer pathways in other regions, thus inhibiting side reactions without significantly increasing internal resistance
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 faster, more efficient, and cost-effective production of conformal thin films on battery electrodes, reducing internal resistance and improving film uniformity and adhesion, while maintaining mechanical stability and ion conductivity.
Implementation Method 1
exposing the battery electrode to the first liquid solution to produce a partially coated battery electrode having a layer comprising an adsorbed first reagent on the surface of the battery electrode
Implementation Method 2
Liquid-phase delivery of reagents takes advantage of the energy of solvation to mobilize reagents instead of relying on high-temperature thermal evaporation
Implementation Method 3
the at least second reagent reacts with the first adsorbed reagent of the partially coated battery electrode to produce a fully coated battery electrode comprising a monolayer of thin film coated onto the surface
Data Source
AI summary
Methods, systems, and compositions for the liquid-phase deposition (LPD) of thin films. The thin films can be coated onto the surface of porous components of electrochemical devices, such as battery electrodes. Embodiments of the present disclosure achieve a faster, safer, and more cost-effective means for forming uniform, conformal layers on non-planar microstructures than known methods. In one aspect, the methods and systems involve exposing the component to be coated to different liquid reagents in sequential processing steps, with optional intervening rinsing and drying steps. Processing may occur in a single reaction chamber or multiple reaction chambers.