Defect-engineered mesoporous ternary nanoarchitecture of zinc-cobalt-oxide/nitrogen-doped graphene as anode material in lithium ion batteries

Abstract

We report a defect-engineered self-assembly route to a mesoporous ternary ZnCo2O4/nitrogen-doped graphene nanoarchitecture as an anode material for lithium ion batteries through a hydrothermal and thermal annealing process. A hetero-nanostructure showed flower-like ZnCo2O4 nanosheets which were well dispersed and firmly decorated on nitrogen-doped reduced graphene oxide, as atomic-scale defects such as nitrogen-doped sites and oxygen-functional groups in chemically modified graphene oxide can be more reactive nucleation sites to anchor metallic nanoparticles strongly. Strong synergy between N-doped graphene and ZnCo2O4 is observed as a high-performance anode electrode material for much higher capacity levels and more durable electrochemical stability in lithium ion batteries. The mesoporous nanoarchitecture electrode shows enhanced reversible performance in cyclic anode tests, maintaining a specific energy capacity of 998 mAh g(-1) after 30 cycles at current density of 100 mA g(-1).