|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||High Temperature Electrochemistry IV
||Advances in solid oxide membrane based electrolysis for solar-grade silicon deposition
||Michelle Sugimoto, Haoxuan Yan, Federico Coppo, Adam Powell, Uday B. Pal
|On-Site Speaker (Planned)
Currently, photovoltaic (PV) cells, which utilize available solar energy with zero end-user emissions, are dominated by polycrystalline silicon designs. The cost of PV has dropped drastically in the last several decades. However, the current solar-grade Si production process is highly energy and cost intensive, and is not easily scaled up. In this work, an alternate production route, akin to the Hall-Héroult process used for aluminum production, has been developed. Here, we present a high-temperature, molten oxide-fluoride bath electrolysis cell capable of depositing a planar layer of Si starting from abundantly sourced silica onto a Si wafer cathode. An optimized alternating square wave signal was developed and applied across the cell in order to periodically redissolve any dendritic growth back into the molten salt. This ensured a uniform, planar deposition of Si. Finally, an optimized rare-earth nickelate anode was developed, removing costly and/or volatile precious metals from the system.
||Process Technology, Sustainability, High-Temperature Materials