Synthesis of Co3O4 Nanoparticles Wrapped Within Full Carbon Matrix as an Anode Material for Lithium Ion Batteries

摘要

A facile polyol-assisted pyro-synthesis method was used to synthesize Co_3O_4 nanoparticles embedded into carbon matrix without using any conventional carbon source. The surface analysis by scanning electron microscopy showed that the Co_3O_4 nanoparticles(~20 ± 5 nm) are tightly enwrapped within the carbon matrix. CHN analysis determined the carbon content was only 0.11% in the final annealed sample. The Co_3O_4@carbon exhibited high capacities and excellent cycling performance as an anode at various current rates(such as 914.4 and 515.5 mAh g^(-1) at 0.25 and1.0 C, respectively, after 50 cycles; 318.2 mAh g^(-1) at a high current rate of 5.0 C after 25 cycles). This superior electrochemical performance of the electrode can be attributed to the various aspects, such as,(1) the existence of carbon matrix, which acts as a flexible buffer to accommodate the volume changes during Li^+ion insertion/deinsertion and facilitates the fast Li^+and electron transfer and(2) the anchoring of Co_3O_4 nanoparticles within the carbon matrix prevents particles agglomeration.