Rapid Synthetic Route to Nanocrystalline Carbon-Mixed Metal Oxide Nanocomposites with Enhanced Electrode Functionality

Abstract

A rapid synthetic route to nanocrystalline carbon-incorporated mixed metal oxide nanocomposites with enhanced electrode performance for lithium ion batteries is developed by applying a very short heat-treatment of layered double hydroxide (LDH) precursor under C2H2 flow. Employing C2H2 atmosphere makes possible the rapid synthesis of nanocrystalline C-NiO-NiFe2O4 nanocomposite via the calcination of the Ni-Fe-LDH precursor at 300 °C in a very short period of 5 min. In the case of ambient atmosphere, a prolonged calcination time of several hours is demanded to induce a complete phase transformation from Ni-Fe-LDH to electrochemically active NiO-NiFe2O4 nanocomposite, highlighting the usefulness of C2H2 atmosphere in promoting the formation of mixed metal oxide nanocomposite. The present C-NiO-NiFe2O4 nanocomposite shows much better anode performance for lithium ion batteries with greater discharge capacity and better cyclability than do the NiO-NiFe2O4 nanocomposites prepared by the prolonged calcination of LDH under ambient atmosphere. The superior electrode activity of the present C-NiO-NiFe2O4 nanocomposite is attributable to the optimization of charge transfer induced by the enhanced electrical conductivity and a short diffusion length of Li ion. The present C2H2-assisted phase transition of LDH precursor provides a convenient, economic, and scalable synthetic way to carbon-mixed metal oxide nanocomposites with promising electrode performance for lithium ion batteries. © 2016 American Chemical Society.