Effect of MXene Addition on the Thermoelectric and Mechanical Properties of Skutterudite CoSb3

Skutterudite CoSb3 is a high-performance thermoelectric material for mid-temperature range applications. When combined with a 2D material, Ti3C2Tx (T represents functional groups such as –F, –OH, and –O) MXene and CoSb3 showed improved electrical conductivity with reduced lattice thermal conductivity values. This work employs the four-phonon scattering mechanism using a modified Debye–Callaway model to show enhanced phonon–phonon scattering in the composite samples. Ti3C2TxMXene is proven to be a viable alternative for nanoinclusions in skutterudites, as evidenced by a 137% rise in the figure of merit (ZT) value at 623 K. At higher temperatures, pristine CoSb3 and CoSb3 + Ti3C2TxMXene composites show bipolar behavior in Seebeck coefficient data. Besides a 127% increase in hardness for the 3 wt % Ti3C2TxMXene-incorporated sample, adding MXene further enhances the load-bearing capacity of skutterudite samples.