Applied Surface Science, Vol.441, 69-76, 2018
Coupling Mo2C@C core-shell nanocrystals on 3D graphene hybrid aerogel for high-performance lithium ion battery
Hybrid aerogel by dispersing Mo2C@C core-shell nanocrystals into three-dimensional (3D) graphene (Mo2C@C-GA) has been successfully prepared through two-step methods. Firstly, carbon-coated MoMo2 nanocrystals uniformly anchor on 3D graphene aerogel (MoMo2@C-GA) via hydrothermal reaction. Then the MoMo2@C-GA precursor is transformed into Mo2C@C-GA after the following carbonization process. Furthermore, the freeze-drying step plays an important role in the resulting pore size distribution of the porous networks. Moreover, graphene aerogels exhibit extremely low densities and superior electrical properties. When evaluated as anode material for lithium ion battery, Mo2C@C-GA delivers excellent rate capability and stable cycle performance when compared with C-GA and Mo2C nanoparticles. Mo2C@C-GA exhibits the initial discharge capacity of 1461.4 mA h g (1) at the current density of 0.1 A g (1), and retains a reversible capacity of 1089.8 mA h g (1) after 100 cycles at a current density of 0.1 A g (1). Even at high current density of 5 A g (1), a discharge capacity of 623.5 mA h g (1) can be still achieved. The excellent performance of Mo2C@C-GA could be attributed to the synergistic effect of Mo2C@C nanocrystals and the 3D graphene conductive network. (C) 2018 Elsevier B.V. All rights reserved.