Corrosion behavior of various conductive materials in Sb3Sn7 alloy at 450 °C

Sb-Sn alloys are attractive positive electrode materials for liquid metal batteries. In this work, the corrosion behavior of three steels (f/m steel T91, austenitic steels SS304 and SS316L), one Fe-Co-Ni alloy (4J29 Kovar), molybdenum, and three MAX-phase coatings (Cr2AlC, Ti2AlC, Ti3AlC2) is investigated in static exposures to liquid Sb3Sn7 alloy at 450 °C for 750 h in oxygen-poor conditions. The results reveal unacceptably high corrosion rates in the range 0.5 to 1.3 µm/h for the Fe-based alloys, while Mo and MAX-phases show promising corrosion resistance with corrosion rates below 0.1 mm/a despite a small arsenic impurity of the liquid metal.