NaCl‐Templated and Polyvinylpyrrolidone‐Assisted Fabrication of a MnO/C‐rGO Composite as a High‐Capacity Anode Material for Li‐Ion Batteries

Abstract

A 3D hierarchically‐heterostructured manganese oxide/pyrolytic carbon and reduced graphene oxide composite material (MnO/PC‐rGO) is synthesized by the in situ redox reaction between a PC‐rGO carbon aerogel framework and KMnO4 solution, followed by heat treatment in an inert atmosphere. Herein, the 3D porous PC‐rGO carbon aerogel is prepared via crystal sodium chloride (NaCl)‐templated and polyvinylpyrrolidone (PVP)‐assisted freeze drying in the presence of graphene oxide (GO) and high‐temperature pyrolysis. As an anode material for lithium‐ion batteries, this composite exhibits a high charge capacity of ≈1030 mAh g−1 at 100 mA g−1 and 515 mAh g−1 at 2000 mA g−1. After cycling at 500 mA g−1 for 200 cycles, the capacity retention is ≈70%, demonstrating much superior lithium storage performance over the MnO/PC composite prepared under similar conditions. The superior electrochemical performance is ascribed to its good electrode kinetics behavior and the supernumerary capacity contribution of the PC‐rGO carbon framework due to the presence of rGO in the composite. As a synergic carbon support, the rGO can not only increase the specific capacity and rate capability but also improve the cyclability due to the enhanced electrical conductivity and the buffering effect of the flexible PC‐rGO against a large volume change during cycling.