High Entropy Oxide Coating to Mitigate Molten Salt Corrosion in Concentrated Solar Power Systems

Project Overview

Renewable Concentrated Solar Power (CSP) systems have been rapidly deployed e.g., at an increasing rate of ~50%/year. However, at their high operating temperatures (e.g., 800 °C), molten salt corrosion of the structural materials in the CSP system exhibits a high corrosion rate of > 0.5 mm/year. This study demonstrated the feasibility of an efficient reduction in the corrosion rate by applying a new high entropy oxide (HEO) coating. Specifically, this study involved (1) depositing and characterization of an equal-molar HEO coating on stainless steel substrates and (2) demonstration of the improved corrosion resistance of coated coupons in molten chloride salts used in CSP environments. This pioneering study inspires the development of mitigation technologies in reducing corrosion rate and is in support of relevant energy and resource security and other national security missions that will guide future efforts in this field toward addressing DOE grand challenges for CSP. 

Mission Impact

The proposed study aligns with LLNL's Core Competencies in Energy and Resource Security and in Accelerated Materials and Manufacturing. 

Specifically, the work can lay the foundation for new programs in DOE Nuclear Energy and Solar Energy Technology Offices; extend into other areas of corrosion research at Lawrence Livermore National Laboratory (LLNL) and improve upon current lab expertise; and leverage knowledge and facilities of the previously and currently funded LLNL LDRD research and bridge integration with the ongoing multimodal high temperature and pressure corrosion work.

Publications, Presentations, and Patents

Yakun Zhu, "Role of Ti oxide and Ti nitride surface films in H trapping and transporting" (Poster Presentation, Session A Poster # 20, Gordon Research Conference - High Temperature Corrosion, New London, NH, July 2023). IM release # LLNL-ABS-844776

Yakun Zhu, "High entropy oxide coating to mitigate molten salt corrosion in concentrated solar power" (Presentation, LEAF LLNL seminar presentation, Livermore, CA, Jan 30, 2023).

Yakun Zhu, "Preliminary discussion with GM for collaboration" (Presentation, Jan 2023). IM release # LLNL-PRES-844171

Zhu, Yakun, et al. Feb 6, 2023. "Electrochemical Characteristics of Intermetallic Phases in Al–Cu–Li Alloys." J. Electrochem. Soc. 170 021502
doi: 10.1149/1945-7111/acb6bb. IM release # LLNL-JRNL-827601