Reduced graphene oxide supported quasi-two-dimensional ZnCo2O4 nanosheets for lithium ion batteries with high electrochemical stability.

In this work, quasi two dimensional spinel ZnCo2O4 (ZCO) nanosheets constituted by ZCO grain with different size were prepared via a facile solvothermal method and followed by a post-treatment. It shows that the small ZCO grain can be obtained by a fast cooling post-treatment. Further, to enhance the conductivity of ZCO, uniform and compact ZCO nanosheets was in-situ grown on reduced graphene oxide (rGO), which was employed as template. When used as anode for lithium ions battery (LIB), rGO@ZCO has a large reversible capacity of 1107.2 mAh·g-1 at 100 mA·g-1 after 100 cycling, which is the highest among all ZCO samples. Moreover, when the current density is from 50 to 500 mA·g-1, the capacity of rGO@ZCO decreased from 1046.5 to 527.6 mAh·g-1, implying the superior rate ability. The electrochemical analysis together with calculations demonstrates that the unique structure is beneficial to promote the charge transport and adapt the volume change in charge-discharge process, resulting in expected LIB performance.