Porous MnO2/ carbon Hybrid Material with Improved Electrochemical Performance

Abstract

In this work, MnO2 nanoparticles were embedded in a carbon matrix as a porous composite, fabricated using a simple chemical route followed by low-temperature annealing, with activated carbon (AC) as the carbon source in the composite preparation. The porous MnO2/carbon structures contained some selective nanoparticles coated with carbon. The structural feature was identified by transmission electron microscopy (TEM). The surface area and pore size distribution of the materials were investigated by N2 adsorption/desorption isotherms, and demonstrated a high surface area of about 80 m2 g-1. AC is a readily available carbon source that can easily form a composite with MnO2 nanoparticles, forming a distinctive porous morphology. When employed as an anode material for lithium-ion batteries (LIB), the composite electrode demonstrated high specific capacities with an initial discharge capacity of 2500 mAh g-1 and maintained about 1391 mAh g-1 after fifty cycles. It also demonstrated excellent high rate performance, delivering more than 500 mAh g-1 of specific capacity at 3000 mA g-1, which is a higher capacity than a conventional graphite anode. Overall, the MnO2/ carbon composite electrode delivered superior anode performance, which was attributed to the improved surface area of the carbon hybridized MnO2 nanoparticles. The porous composite has benefits for lithium storage performance.