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 MoC nanoparticles through the electrospinning technique and heat treatment is proposed.The carbonization temperature of the precursors is the key factor for the formation of MoC nanoparticles on the carbon nanofibers(MCNFs).Compared with the MoN 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 gat 100 mA g),a much reduced discharge-charge voltage gap,and a long-term life(124 cycles at 200 mAgwith a specific capacity limit of 500 mAh g).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 Oas well as avoid clogging of the discharge product,bulk LiO;(2)the well dispersed MoC nanoparticles not only afford rich active sites,but also facilitate the electronic transfer for catalysis.