Architecting carbon-coated Mo2CTx/MoSe2 heterostructures enables robust potassium storage.

Herein, carbon-coated MoSe2 decorated Mo2CTx MXene heterostructures (MoSe2/Mo2CTx@C) have been fabricated. Mo2CTx works as a dual-function electron/ion conductor, which not only provides high conductivity and mechanical strength, but also prevents the severe self-aggregation of few layered MoSe2 nanosheets. The high reversible capacities of 405 mA h g−1 at 100 mA g−1 after 150 cycles and 258 mA h g−1 at 2000 mA g−1 after 400 cycles could be achieved for a potassium-ion battery. [ABSTRACT FROM AUTHOR]