MnO nanorods coated by Co-decorated N-doped carbon as anodes for high performance lithium ion batteries

Abstract

N-doped carbon (NC)/Co-MnO nanorods were obtained by growing ZIF-67 on the surface of MnO2 nanorods via a PVP-modified method, followed by high-temperature carbonization. The NC/Co-MnO nanorod was consisted with MnO nanorod coated with high conductive and porous NC/Co layer, and the NC/Co layer was further structured with N-doped carbon (NC) and the Co decoration. The NC/Co layer can effectively buffer the volume expansion of MnO during lithium insertion, and further provide efficient channels for electron transport. Besides, the metallic Co nanoparticles in the NC/Co layer also have the effect to adjust the SEI layer, which can make the NC/Co-MnO electrode exhibit good structural stability and excellent electrical properties. Therefore, the NC/Co-MnO electrode showed excellent cyclic and rate performance. High reversible capacitiy of 1277.8 mA h g−1 was obtained after 300 cycles at 200 mA·g−1. When the current density was raised to 8000 mA g−1, a capacity of 708.3 mA h g−1 was retained. This composite shows great potential as low-cost and high-performance electrodes for lithium ion batteries.