Carbon-coated MnO microparticulate porous nanocomposites serving as anode materials with enhanced electrochemical performances

Porous manganese oxide (Mn2O3) microspheres have been successfully fabricated through annealing the solvothermal lab-made MnCO3 precursor. Experimental results reveal that polyvinyl-pyrrolidone (PVP) plays a pivotal role in controlling the size and uniformity of the MnCO3 microspheres. The carbon-coated MnO porous microspheres (MnO@C) with a specific surface area of 45.6 m(2) g(-1) and pore size of ca. 30 nm were obtained by carbonization of pyrrole coated porous Mn2O3. The carbon layer with a thickness of ca. 3 nm was deposited on the surface and the inner wall of pores. Electrochemical tests demonstrated that the as-prepared porous MnO@C electrode materials possessed a reversible capacity of 525.4 mAh g(-1) after 100 cycles at a current density of 100 mA g(-1) and the capacities of 590.6, 478.8, 353.8 and 238.2 mAh g(-1) at 100, 200, 400, and 800 mA g(-1), respectively. The MnO@C porous materials exhibit higher cycling and rate performances than the corresponding porous Mn2O3 mainly attributed to the carbon coating, which could efficiently buffer the volume change during the lithiation/delithiation and improve the electronic conductivity among MnO particles. (C) 2014 Elsevier Ltd. All rights reserved.