Smart reconstruction of dual-carbon decorated MnO for anode with high-capacity and ultralong-life lithium storage properties

Abstract

To tackle the issues of inferior cycling stability and low intrinsic conductivity for MnO as anode material for lithium ion batteries (LIBs), we design and rationally confine MnO@C core-shell nanorods homogeneously in the flexible graphene matrix via a facile process. The obtained composite exhibits a high reversible capacity (1165.3 mAh g−1 at 0.1 A g−1), excellent rate capability (618.5 mAh g−1 at 2 A g−1), and superior cyclability (almost no capacity fading even after 4000 cycles), which has been rarely reported for LIBs. The lithiation and delithiation behavior suggests that the further oxidation of Mn2+ to Mn4+ and the surface pseudocapacitance contribute to the distinctive capacity enhancement. Additionally, the structure reconstruction from MnO nanorods to nanoworm-like and subsequently to nanoparticles achieves faster kinetics of conversion reactions. The excellent rate capability benefits from the presence of 2D dual conductive graphene and amorphous carbon, as well as the synergistic effect between them for elevating the transportation of both lithium ions and electrons. Moreover, the superb cyclic stability can be attributed to the well-defined dual-carbon decoration that alleviates the volume variation as well as the agglomeration and dissolution of MnO, and yields a long-life anode material.