Oriented Apatite Oxide Electrolyte Films on Low-Cost Substrates
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Solution Overview
Problem
Conventional methods for producing substrate/oxide ion conductor film complexes are limited by the need for special silicon substrates, which are expensive and difficult to use for forming thin electrolyte layers, especially in free-standing membrane electrolyte assemblies, and require specific crystal faces for orientation, restricting their application and increasing costs.
Innovation Solution
A substrate/oriented apatite-type composite oxide film complex is developed, where an oriented apatite-type composite oxide film with a thickness of 10.0 µm or less is formed on a metal, alloy, ceramic, or composite material substrate using a sputtering method with a target of high relative density, and subjected to heat treatment under controlled oxygen partial pressure to achieve high orientation and crystallization as an apatite structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods using silicon substrates are employed to produce substrate/oxide ion conductor film complexes, then oriented oxide ion conductor films can be obtained, but the substrate selection is limited, costs increase, and forming thin electrolyte layers becomes difficult
Solution Approach 1:
The invention replaces specialized silicon substrates with universal metal substrates that can serve multiple functions: as a substrate for film formation, as an electrode material, and as a structural component. This allows the same substrate to fulfill multiple roles in the electrochemical device, eliminating the need for separate silicon substrates and enabling broader material selection while maintaining film orientation capability
Solution Approach 2:
The invention changes the substrate material parameters from silicon-based to metal-based materials with specific crystal structures (FCC, BCC, HCP) and crystallographic orientations. By selecting metals with appropriate lattice parameters and crystal orientations, the substrate can induce epitaxial growth and orientation of the oxide ion conductor film without requiring specialized silicon substrates
2Manufacturing precision
If silicon substrates with specific crystal faces are used to achieve film orientation, then oriented oxide ion conductor films can be produced, but the process complexity and cost increase
Solution Approach 1:
The invention uses conventional metal substrates that are easier and cheaper to prepare than specialized silicon substrates. These metal substrates can be readily obtained, cleaned, and prepared without complex procedures, making the overall device simpler and more cost-effective while still achieving the desired film orientation through the metal substrate's crystal structure
3Area of stationary object
If thick oxide ion conductor layers are formed on silicon substrates, then complete coverage can be achieved, but the electrolyte layer thickness increases reducing ion conductivity
Solution Approach 1:
The invention changes the deposition parameters by using metal substrates that allow for better adhesion and more uniform film formation. This enables achieving complete area coverage with thinner film layers, as the metal substrate provides superior nucleation sites and growth conditions compared to silicon substrates, resulting in thinner yet fully-covered electrolyte layers that maintain high ion conductivity
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 approach allows for the easy production of a substrate/oriented apatite-type composite oxide film complex that can be used as a solid electrolyte in batteries and sensors, enhancing power generation characteristics and enabling film formation on various substrates without material restrictions, including those with complex shapes like cylindrical forms.
Implementation Method 1
an amorphous composite oxide film is formed on a substrate by using a target having a relative density of 80% or more and comprising a composite oxide having the same constitutive element as the amorphous composite oxide film to be formed by a sputtering method
Implementation Method 2
the amorphous composite oxide film is then heated and subjected to a heat treatment at 800°C or more under an atmosphere in which an oxygen partial pressure is 1.0 × 10^-4 atm or less, thereby the amorphous composite oxide film is crystallized as an apatite structure and oriented
Implementation Method 3
the amorphous composite oxide film is then heated and subjected to a heat treatment at 800°C or more under an atmosphere in which an oxygen partial pressure is 1.0 × 10^-4 atm or less
Data Source
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AI summary
The purpose of the present invention is to propose a new substrate/oriented apatite-type composite oxide film complex which is suitable as a solid electrolyte for a battery, a sensor, a separation membrane, or the like, and can be produced inexpensively. Proposed is a substrate/oriented apatite-type composite oxide film complex provided with an oriented apatite-type composite oxide film on a substrate, wherein a film thickness of the oriented apatite-type composite oxide film is 10.0 µm or less, a degree of orientation (Lotgering method) thereof is 0.6 or more, and a material of the substrate at a side on which at least the oriented apatite-type composite oxide film is formed is a metal, an alloy, a ceramic, or a composite material thereof.