Sustainable thermoelectric materials: Utilizing Fukushima weathered biotite via molten salt treatment

Abstract

This study examines the utilization of Fukushima weathered biotite (WB) as an alternative to conventional thermoelectric materials traditionally derived from rare and toxic substances. WB underwent milling, classification, and subsequent heat treatment via molten-salt treatment to produce crystals exhibiting conductivity akin to semiconductors within the 650–850 °C range. Evaluation of WB and the derived crystal’s electrical conductivity and Seebeck coefficient showcased their viability for high-temperature thermoelectric applications. Consequently, WB attained a dimensionless figure of merit (ZT) of 0.015, signaling its potential as a thermoelectric material that surpasses 650 °C.