Preparation of N-Doped Carbon/Cobalt Ferrite Hybrid Nanocomposites for Lithium Ion Batteries Anodes

Transition metal oxides (TMOs) have much higher theoretical lithium storage capacities than that of the commercial graphite anode, but severe volume expansion (160–300%) and lower conductivity will result in poor cycle stability and low rate performance, which seriously hinder their applications. Developing inexpensive and efficient strategy to manufacture carbon/TMOs hybrids with good cycle stability and high rate performance is highly desired. Here, we report a facile approach to synthesize nitrogen-doped carbon/cobalt ferrite hybrids using the cheap renewable biomass, glucose and starch, as the carbon source. The resultant N-doped carbon/cobalt ferrite hybrid nanocomposites were investigated in terms of their morphology, structure, composition and electrochemical lithium storage performance. The results show that the hybrid composites possess porous structure and TMOs nanocrystals (~5.7 nm), which can not only effectively alleviate the sharp volume changes of cobalt ferrite (186%) during repeated lithiation/delithiation process, but also provide efficient electron and ion transport channels, demonstrating excellent rate performance and remarkable cycle stability. In particular, a high reversible capacity of 411 mAh/g was successfully maintained without decay over 200 cycles at a high current density of 3 A/g, exhibiting the potential as a promising lithium ion batteries anode material.