Designed construction and validation of carbon-free porous MnO spheres with hybrid architecture as anodes for lithium-ion batteries

Abstract

Porous micro/nanostructures of earth abundant and ecobenign metals are emerging as advanced green materials for use in electrochemical energy storage devices. We present here the custom designed construction of a hybrid architecture containing porous MnO microspheres, formed out of hierarchically assembled nanoparticles using a template-free co-precipitation method, wherein the sacrificial template growth of porous spheres has been obtained by a solution mediated and time dependent oxidation strategy. The nanoporous channels in the MnO microspheres and the nanosized primary particles of MnO anodes in synergy increase the electrolyte percolation, resulting in a discharge capacity of 1200 mA h g⁻¹ at a current density of 50 mA g⁻¹ and a capacity as high as 450 mA h g⁻¹ under the 1000 mA g⁻¹ condition. The study assumes importance based on the fact that engineering of electrode materials is typically challenging, wherein design, preparation and fabrication of tailor-made electrodes with a desirable micro/nanocrystalline assembly play a critical role, especially when recommended for high capacity and high-rate applications in electrochemical energy storage devices. Further, this communication elaborates the designed construction and validation of porous MnO microspheres engineered through a time dependent process protocol as economically viable and environmentally benign anodes for lithium-ion batteries.