Co3O4/porous carbon nanofibers composite as anode for high-performance lithium ion batteries with improved cycle performance and lithium storage capacity

摘要

Co3O4 is a promising candidate as an anode material for the next generation lithium ion batteries because of its high theoretical storage capacity and energy density. However, the disadvantages of poor capacity retention caused by large volume changes during cycling and low rate capability due to its poor electronic conductivity frustrate its practical applications. We have developed a binary nanocomposite based on Co3O4 and porous carbon nanofibers synthesized via an electrospinning method followed by thermal treatment. As an anode for lithium ion batteries, the Co3O4/ porous carbon nanofibers composite exhibits a remarkably improved electrochemical performance in terms of lithium storage capacity (869.5mAhg(-1) at 0.1 C), high-initial Coulombic efficiency (73.8%), cycling stability (94.9% capacity retention at 50 cycles), and rate capability (403.6mAhg(-1) at 2 C at 25 cycles) compared to pure Co3O4. This improvement is attributed to the introduction of porous carbon nanofibers which could improve electrical conductivity of material and accommodate the volume expansion/contraction of Co3O4 nanoparticles during cycling.