Hierarchical MnO@C Hollow Nanospheres for Advanced Lithium-Ion Battery Anodes

Abstract

Rational morphology design is of great significance for achieving superior cycling performance and rate capability for lithium-ion batteries. Here we designed and fabricated hierarchical MnO@C hollow nanospheres (HNSs) consisting of nitrogen-doped carbon outer shells and MnO hollow spheres composed of ultrathin MnO nanosheets. The hierarchical hollow structures provided abundant active sites for lithium storage while accommodating the volume change, leading to high reversible capacity and rate performance. The graphitic carbon shells improved the electrical conductivity and restricted the volume expansion of MnO, which helped to achieve enhanced cycling stability and improved rate capability. When used as an anode material for lithium-ion batteries, the hierarchical MnO@C HNSs retained a capacity of 839 mAh g–1 after 900 cycles at 1 A g–1. The excellent electrochemical performance of these MnO@C HNSs may be attributed to the synergetic effects of the hierarchical hollow structure and the conductive carbon coating layer. This work provided a controllable approach toward hierarchical hollow structures of desired hybrid materials for high-performance electrodes.