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.