Lithium Coating Deposition with Molten Target Agitation
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Solution Overview
Problem
The challenge in applying lithium coatings to substrates via physical vapor deposition (PVD) is the formation of a passivation layer on lithium targets, which hinders vaporization and leads to arcing issues, requiring high vacuum conditions that are costly and inconvenient.
Innovation Solution
Agitating a molten lithium target using a magnetohydrodynamic effect to disperse the passivation layer, allowing for increased purity and reduced arcing, enabling effective lithium deposition at lower vacuum pressures and higher deposition rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high vacuum conditions are used to reduce atmospheric components and minimize passivation of lithium, then the passivation layer formation is reduced, but the cost and inconvenience increase greatly
Solution Approach 1:
The patent applies preliminary action by forming a protective atmosphere (inert gas or vacuum) before the passivation layer can significantly form on the lithium target. The method establishes controlled conditions upfront that prevent passivation during the coating process, eliminating the need for extreme high vacuum conditions while still protecting the lithium from atmospheric reaction.
Solution Approach 2:
The patent directly applies the inert atmosphere principle by introducing an inert gas environment or controlled vacuum atmosphere that prevents atmospheric components (oxygen, nitrogen, carbon dioxide) from reacting with the lithium target. This creates a protective environment that minimizes passivation layer formation without requiring the costly and inconvenient extreme high vacuum conditions of conventional methods.
2Quantity of substance
If a passivation layer is present on the lithium target, then atmospheric components are reduced, but vaporisation energy transfer is hindered and arcing occurs
Solution Approach 1:
The patent applies parameter changes by carefully controlling the pressure and composition of the atmospheric environment. By adjusting these parameters to specific ranges, the method maintains enough atmospheric components to prevent excessive passivation while keeping them low enough to allow efficient vaporisation energy transfer to the lithium target, avoiding both passivation-related arcing and productivity loss.
3Reliability
If conventional PVD methods are used, then lithium coating can be deposited, but high vacuum conditions are required which increase cost and reduce deposition efficiency
Solution Approach 1:
The patent replaces the requirement for extreme high vacuum conditions with a controlled inert atmosphere environment. This allows lithium coating deposition to proceed efficiently at higher pressures, eliminating the costly and time-consuming vacuum requirements of conventional PVD methods while maintaining coating quality and deposition efficiency.
Solution Approach 2:
The patent fundamentally changes the operating pressure parameter from extreme high vacuum to controlled higher pressure inert atmosphere. This parameter change enables the use of simpler, less expensive equipment while maintaining effective lithium vaporisation and coating deposition, directly addressing the cost and efficiency issues of conventional methods.
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 facilitates efficient lithium coating deposition at lower vacuum pressures, reducing costs and improving deposition rates while maintaining mechanical strength and purity, overcoming the limitations of conventional PVD processes.
Implementation Method 1
Agitating the molten lithium target comprises creating a magnetohydrodynamic effect in the lithium target
Implementation Method 2
vaporisation of material from a target
Implementation Method 3
condensation of the vaporised material onto the substrate to generate a deposited coating
Implementation Method 4
a plasma formed from a working gas is kept close to the surface of a target by use of a magnetic field
Implementation Method 5
Sputtering creates vaporised material from the target through bombardment with accelerated gaseous ions
Data Source
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AI summary
A method of forming a lithium coating on a substrate, the method comprising: melting a solid lithium target to form a molten lithium target; agitating the molten lithium target; vaporising at least part of the agitated molten lithium target to form a vaporised material; and condensing the vaporised material on a substrate to form a lithium coating.