Solid-State Electrolyte Powder Sintering to Prevent Passivation
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Solution Overview
Problem
The surface of inorganic ceramic solid-state electrolyte powder is susceptible to oxidation, forming an air passivation layer that increases interface impedance and reduces cycling performance, and conventional machining methods are ineffective for treating powders.
Innovation Solution
A zirconium compound layer is formed on the inner surface of a container before sintering a precursor mixture, which includes zirconium source compounds and lithium source compounds, followed by an aerobic sintering process to form the solid-state electrolyte powder, and a subsequent cleaning process with an acid and alcohol solution to remove the passivation layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional machining methods such as grinding/polishing are used to treat air passivation layers, then the passivation layer can be removed from bulk materials, but these methods cannot treat powders effectively
Solution Approach 1:
The patent replaces mechanical machining methods (grinding/polishing) with a chemical cleaning method using acid and alcohol solutions. This chemical approach can effectively treat powder surfaces without the limitations of mechanical contact, thereby resolving the contradiction between removing passivation layers and treating powder form.
2Ease of operation
If the solid-state electrolyte powder is exposed to air during processing, then the powder can be handled and processed, but the surface is susceptible to oxidation forming a passivation layer that increases interface impedance
Solution Approach 1:
The patent applies acid and alcohol cleaning treatments to remove the passivation layer immediately after sintering and before further processing or application. This preliminary action prevents the oxidized surface from causing interface impedance problems in subsequent steps, maintaining both ease of handling and ionic conductivity.
3Reliability
If a zirconium compound layer is formed on the container inner surface before sintering, then the passivation layer formation is prevented and ionic conductivity is enhanced, but an additional process step is required
Solution Approach 1:
The zirconium compound layer is applied to the container inner surface before sintering, creating a protective environment that prevents passivation layer formation during the sintering process. This preliminary protective measure eliminates the need for subsequent complex surface treatments, as the cubic crystal phase forms directly with high ionic 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
The method effectively prevents the formation of passivation layers, enhancing ionic conductivity and improving the cycling performance of the solid-state electrolyte powder by promoting the formation of a cubic crystal phase and removing surface impurities.
Implementation Method 1
the surface of the inorganic ceramic solid-state electrolyte powder is susceptible to oxidation to form an air passivation layer
Implementation Method 2
An aerobic sintering process is performed to form the solid-state electrolyte powder
Implementation Method 3
promoting the formation of a cubic crystal phase
Implementation Method 4
a cleaning process is performed with an acid and alcohol solution to remove the passivation layer
Data Source
Figure 1
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AI summary
A method of forming a solid-state electrolyte powder includes the following steps. A zirconium compound layer is formed on an inner surface of a container. A precursor mixture is placed on the zirconium compound layer. The precursor mixture includes a first salt group and a second salt group. The first salt group includes zirconium source compound, lanthanum source compound, aluminum source compound, titanium source compound, tantalum source compound, or combinations thereof. The second salt group includes lithium source compound. An aerobic sintering process is performed to form the solid-state electrolyte powder.