Just starting to explore 2D MXenes, including Nb2C. Nb2C MXene, like many other types, should be conductive when bare (not terminated with O or OH), but becomes semiconductive when they do. The 2D layered Nb2C MXene is very different from NbC, and its ideal for electrical conductivity study in confined domains (particularly on the thickness axis). There is a literature you can refer on the use of Nb2C in Li battery, J. Am. Chem. Soc. 135, 15966-15969 (2013)