CoMoO4-N-doped carbon hybrid nanoparticles loaded on a petroleum asphalt-based porous carbon for lithium storage

Abstract

Ultrafine transition metal oxides have great potential for efficient lithium storage but some key problems, such as a strong tendency to aggregate and poor electrical conductivity, need to be solved for their possible application. Here, hybrid nanoparticles of CoMoO4 and N-doped carbon were formed in a petroleum asphalt-based porous carbon prepared by a template method. A Co-based zeolitic imidazolate framework (ZIF-67) was then synthesized in-situ in its pores from Co(NO3)2·6H2O and 2-methylimidazole. The porous carbon was impregnated with Na2MoO4·2H2O and polyvinyl pyrrolidone, followed by solvothermal treatment at 180 oC for 24 h and finally calcination to convert the loaded components into hybrid nanoparticles of CoMoO4 and N-doped carbon. Results indicate that the N-doped carbon boosts the electron transport ability of CoMoO4 and efficiently prevents its aggregation. At an optimal CoMoO4 loading the composite was used as an anode material in a lithium ion battery and delivered a reversible specific capacity of 818 mAh g-1 at 1 A g-1, an initial coulombic efficiency of around 70%, and outstanding cycle and structural stability during cycling. The strategy reported here may open up a new avenue for the rational design and construction of well-designed electrode materials for energy storage.