Boosting the high-rate performance of lithium-ion battery anodes using MnCo2O4/Co3O4 nanocomposite interfaces.

ABSTRACT

Herein, a mesoporous MnCo2O4/Co3O4 nanocomposite was fabricated using a polyvinylpyrrolidone (PVP)-assisted hydrothermal synthesis method by maintaining only the non-stoichiometric ratio of Mn and Co (2 6), leading to an extra phase of Co3O4 coupled with MnCo2O4. Microstructural analysis showed that the obtained sample has a uniform nanowire-like morphology composed of interconnected nanoparticles. The stoichiometric ratio (2 4) was maintained to synthesize pure MnCo2O4 for comparative analysis. However, the obtained structure of pure MnCo2O4 was found to be irregular and fragile. After their employment as anode-active materials, the nanocomposite electrode showed superior high rate capability (1043.8 mA h g-1 at 5C) and long-term cycling stability (773.6 mA h g-1 after 500 cycles at 0.5C) in comparison to the pure MnCo2O4 electrode (771.5 mA h g-1 at 5C and 638.9 mA h g-1 at 0.5C after 500 cycles). It was believed that the extra phase of Co3O4 may also participate in the electrochemical reactions due to its high electrochemically active nature. Benefiting from the appealing architectural features and striking synergistic effect, the integrated MnCo2O4/Co3O4 nanocomposite anode exhibits excellent electrochemical properties and high cycle stability for LIBs.