Structural engineering of CoMoO₃ nanosheets on cage-like carbon nanoflakes toward enhanced lithium storage performance

Bimetal oxides possess high electronic conductivity and multiple electrochemically active sites owing to their stepwise electrochemical reactions compared with the single metal oxides. However, bimetal oxides still suffer from the severe volume changes upon lithium insertion/delithiation processes, thus leading to poor cycle stability. Herein, we demonstrate the growth of novel CoMoO₃ nanosheets on the cage-like carbon nanoflakes (c-CNFs) through a facile in-situ thermal decomposition strategy. The phase and morphology structures of CoMoO₃ can be readily controlled by adjusting the sintering temperature under the argon atmosphere, changing from 0D CoMoO₄ nanoparticles@c-CNFs (350 ℃, denoted as CoMoO₄ @C) to 0D CoMoO₄ nanoparticles and 2D CoMoO₃ nanosheets co-existed nanohybrids@c-CNFs (450 ℃, denoted as CoMoO_x @C) and 2D CoMoO₃ nanosheets@c-CNFs (550 ℃, denoted as CoMoO₃ @C). When examined as anode materials for LIBs, the CoMoO₃ @C electrode exhibited excellent lithium storage performance. The superior performance of the CoMoO₃ @C electrode could be attributed to the novel CoMoO₃ nanosheet structure combined with the reduced volume change from well-fitted CoMoO₃ @c-CNFs, which delivered a reversible capacity of ~706 mA h/g for 360 cycles at 500 mA/g, higher than that of the CoMoO₄ @C and CoMoO_x @C electrodes.