Graphene aerogel encapsulated Co3O4 open-ended microcage anode with enhanced performance for lithium-ion batteries

Prussian blue analogues are receiving a great deal of attention on the field of energy storage materials. They can provide abundant active sites for the diffusion of various ions and their stable framework structure brings excellent cycling stability to the electrode. Despite this, their worse capacity retention and cycle life and the complexity of their electrochemical reaction mechanisms restrict their practical applications as the anode of lithium-ion batteries (LIBs) seriously. In this work, graphene aerogel encapsulated Co3O4 open-ended microcage (Co3O4 [email protected]) is synthesized via simply etching and hydrothermal methods. While applied as the anode for LIBs, the reversible capacity remained at 1439 mAh/g after 200 cycles (1 A/g), furthermore, even at a high current density of 10 A/g, the samples still reached a great capacity of 575.2 mAh/g. The excellent electrochemical performance may be attributed to the enhancing conductivity of the material by the addition of graphene aerogel. Moreover, the enlarged surface area provided by the hollow cage structure also increases the reactive active sites, which is conducive to improving the reaction kinetics of the material so as to speed up the reaction and make the reaction more complete. The simple preparation method and the synergistic effect of reduced graphene oxide(rGO) and open-ended microcage structure give the material an ultra-high capacity retention rate and stability. Thus, Co3O4 [email protected] has the potential as a promising anode material for LIBs.