General synthesis of hollow MnO2, Mn3O4 and MnO nanospheres as superior anode materials for lithium ion batteries

Abstract

The use of manganese oxides as promising candidates for anode materials in lithium ion batteries has attracted a significant amount of attention recently. Here, we develop a general approach to synthesize hollow nanospheres of MnO₂, Mn₃O₄ and MnO, using carbon nanospheres as a template and a reagent. Depending on the calcination temperature, time and atmosphere, hollow nanospheres of MnO₂ assembled by randomly dispersed nanosheets, or hollow nanospheres of Mn₃O₄ and MnO composed of aggregated nanoparticles, are produced. The electrochemical properties of the three hollow nanoparticles are investigated in terms of cycling stability and rate capability. They deliver the specific capacities of 840, 1165 or 1515 mA h g⁻¹ after 60 cycles at 100 mA g⁻¹ for MnO₂, Mn₃O₄ and MnO. Even at 500 mA g⁻¹, the reversible capacities could be still kept at 637, 820, and 1050 mA h g⁻¹ after 150 cycles. The outstanding performances might be related with their hollow structure, porous surface and nanoscale size.