Facile synthesis of M-Sb (M = Ni, Sn) alloy nanoparticles embedded in N-doped carbon nanosheets as high performance anode materials for lithium ion batteries

Abstract Sb-based composite have been extensively investigated as anode for LIBs due to its high specific capacity and moderate working voltage. Herein, M-Sb (M = Ni, Sn) alloy nanoparticles encapsulated with N-doped carbon nanosheets were prepared by a facile method. The N-doped carbon nanosheets encapsulated M-Sb nanoparticles, which can prevent the direct exposure of M-Sb nanoparticles to the electrolyte and buffer the volume expansion of alloy nanoparticles during the Li+ insertion/extraction process. As a result, the M-Sb/N-doped carbon nanosheets exhibit outstanding rate performance and long cycling stability. High reversible capacities of 252 and 349 mA h g−1 can be achieved even at 5000 mA g−1 for NiSb/N-C nanosheets and SnSb/N-C nanosheets, respectively. Furthermore, a high capacity of 401 mA h g−1 can be obtained after 600 cycles at 1000 mA g−1 for NiSb/N-C nanosheets, and a high capacity of 537.5 mA h g−1 can be observed after 1000 cycles at 1000 mA g−1 for SnSb/N-C nanosheets.