Decorating carbon nanofibers with Mo2C nanoparticles towards hierarchically porous and highly catalytic cathode for high-performance Li-O2 batteries

A facile synthesis of the hierarchically porous cathode with Mo 2 C nanoparticles through the electrospinning technique and heat treatment is proposed. The carbonization temperature of the precursors is the key factor for the formation of Mo 2 C nanoparticles on the carbon nanofibers (MCNFs). Compared with the Mo 2 N nanoparticles embedded into N-doped carbon nanofibers film (MNNFs) and N-doped carbon nanofibers film (NFs), the battery with MCNFs cathode is capable of operation with a high-capacity (10,509 mAh g −1 at 100 mA g −1 ), a much reduced discharge-charge voltage gap , and a long-term life (124 cycles at 200 mA g −1 with a specific capacity limit of 500 mAh g −1 ). These excellent performances are derived from the synergy of the following advantageous factors: (1) the hierarchically self-standing and binder-free structure of MCNFs could ensure the high diffusion flux of Li + and O 2 as well as avoid clogging of the discharge product, bulk Li 2 O 2 ; (2) the well dispersed Mo 2 C nanoparticles not only afford rich active sites, but also facilitate the electronic transfer for catalysis.