Lithium Coating on Buffer Layers for Large-Area Foil Deposition
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Solution Overview
Problem
Current production technologies for lithium foils with dimensions less than 50 µm and greater than 100 mm are limited due to lithium's mechanical properties, hindering the scaling up of lithium-based battery technologies, and existing deposition methods result in low deposition rates and unwanted lithium coating on nearby components.
Innovation Solution
A method involving a mediator layer made of materials like copper oxide or nickel oxide that chemically reacts with lithium to improve wettability, allowing large-area deposition of lithium by converting it into a solid phase at elevated temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If direct deposition of lithium on copper foil is attempted, then the desired layer thicknesses can be achieved, but poor wetting of copper foil causes the process to fail
Solution Approach 1:
An intermediary layer made of metal oxide (such as copper oxide or nickel oxide) is applied to the substrate surface before lithium deposition. This intermediary layer acts as a mediator that improves the wettability of the substrate with liquid lithium, enabling successful deposition. The metal oxide layer reacts with lithium to form a mediating boundary layer, allowing lithium to spread and form uniform thin layers that would otherwise be impossible to deposit directly on copper or nickel foils.
2Manufacturing precision
If evaporation process is used to deposit lithium on copper foil, then lithium coating can be achieved, but deposition rates are low and nearby components are also coated with lithium
Solution Approach 1:
The metal oxide intermediary layer serves as a selective mediator that enables lithium deposition only on the substrate surface. This layer creates a controlled interface that prevents lithium from coating nearby components while maintaining high deposition rates. The intermediary layer's chemical reactivity with lithium provides a targeted deposition pathway that solves both the low deposition rate and unwanted coating issues simultaneously.
Solution Approach 2:
The process utilizes temperature control to manage the phase of lithium during deposition. By heating the substrate to elevated temperatures, lithium is applied in liquid form which enhances wetting and deposition rate. After deposition, the substrate is cooled to convert the lithium to solid phase, ensuring stable coating. This parameter change approach enables high-rate deposition without compromising coating precision.
3Volume of moving object
If thin lithium foil is laminated to copper foil to achieve thin material thicknesses, then reduced thickness can be achieved, but the mechanical stability of lithium prevents achieving desired thicknesses
Solution Approach 1:
The mechanical lamination process is replaced with a chemical deposition process. Instead of mechanically bonding thin lithium foil to copper foil (which is limited by lithium's mechanical instability), lithium is deposited chemically onto the metal oxide intermediary layer. This substitution allows formation of uniform thin lithium layers through chemical reactions and wetting mechanisms rather than mechanical bonding, achieving thicknesses that were previously impossible due to lithium's mechanical properties.
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
Enables the deposition of lithium on large areas with greater thicknesses and improved substrate wettability, facilitating the production of thin lithium foils suitable for larger battery formats.
Implementation Method 1
The mediator layer is made of a material that reacts with the alkali metal by at least partial chemical reduction
Implementation Method 2
the wettability of the substrate with regard to the alkali metal is improved
Implementation Method 3
the alkali metal is subsequently converted into the solid phase or solid state
Implementation Method 4
converting the lithium into the solid phase or the solid state of aggregation by reducing the temperature
Data Source
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AI summary
The present invention relates to a method for producing a substrate (2) which is coated with an alkali metal (1), in which method a promoter layer (3) which is composed of a material which reacts with the alkali metal (1) by at least partial chemical reduction of the promoter layer (3) is applied to a surface of the substrate (2) and a surface of the promoter layer (3) is acted on by an alkali metal (1) and then the alkali metal (1) is converted into the solid phase and a coating containing the alkali metal is formed.