Template-Assisted Synthesis of Honeycomb-Like CoFe2O4/CNTs/rGO Composite as Anode Material for Li/Na-Ion Batteries

CoFe2O4 is a fascinating anode material due to its high theoretical capacity. However, the low electronic conductivity, limited electrochemical kinetics and huge volume expansion lead to poor electrochemical performance. Here, the CoFe2O4/CNTs/rGO ternary composite with a honeycomb-like structure (PS-CFO/CNTs/rGO) has been synthesized via a spray drying method assisted by polystyrene (PS) soft template. The rational 3D porous structure design not only enhances the transport capacity of Li/Na ions, but also provides buffer spaces for alleviating volume expansion, resulting in rapid electrochemical kinetics and improved electrode integrity during cycling. In particular, to improve the electrochemical performance, a facile pre-treatment process combining heat-treatment and pre-sodiation treatment is first developed for the anode materials of sodium-ion batteries (SIBs). As a result, at 1 A g(-1) after 365 cycles, the pronounced capacity of PS-CFO/CNTs/rGO composite can be maintained at 750 mAh g(-1) for lithium-ion batteries (LIBs), and after 5000 cycles, maintained at 195 mAh g(-1) for the SIBs.