Nano-sized FeSe2 decorated rGO as a potential anode material with enhanced lithium-ion storage

FeSe2@reduced graphene oxide (rGO) composite was prepared by a facile one-step hydrothermal technique with FeSe2 nanoparticles uniformly achored on rGO nanosheets. The nano-sized FeSe2 particles effectively reduce the transfer length of Li ion and increase the sufficient contact area between the electrolyte and active material. Moreover, rGO can not only improve the electrical conductivity, but also prevent the agglomeration of nano-sized FeSe2, as well as accommodate the volume expansion and strain generated from the charge/discharge process. As an anode material applied in Li-ion storage, FeSe2/rGO composite delivers superior specific capacity of 1167.6 mAh/g, good cycling stability (908.2 mAh g−1 after 120 cycles at the current density of 500 mA g−1) and high-power characteristics (728.0 mAh g−1 at 1000 mA g−1), due to coexistent Li-ion storage mechanisms of surface capacitive behavior and diffusion-controlled process.