A novel Sn particles coated composite of SnO_x/ZnO and N-doped carbon nanofibers as high-capacity and cycle-stable anode for lithium-ion batteries

The application of Sn-based materials and transition metal oxides (TMOs) with high theoretical capacities as anodes for lithium ion batteries is severely limited for the low cycle lifespan due to huge volume changes. Combining the Sn-based or TMO materials with one-dimensional (1D) carbon nanofibers as a lithium storage anode is one of the effective means to improve the cycle stability, rate performance, initial coulombic efficiency and electrical conductivity of lithium ion batteries. In this work, a novel Sn particles coated composite of SnO_x/ZnO and N-doped carbon nanofibers (Sn/SnO_x/ZnO@N-CNFs) with high reversibility and long-life lithium storage boosted by pseudocapacitance behavior was fabricated using a simple electrospinning technique and subsequent calcining process. The high theoretical capacity of SnO₂, high Li ion diffusion coefficient of ZnO, as well as stable cycle performance and great conductivity of N-CNFs were integrated into the composite by the synergistic effect, which delivers a high reversible capacity of 588.7 mAh/g after 100 cycles at a current density of 0.5 A/g. More importantly, in the case of great rate performance and cycle stability at high current density, the Sn/SnO_x/ZnO@N-CNFs electrode is endowed with significantly improved initial coulombic efficiency and prominent advantage in electrical conductivity. The comprehensive performance, facile material fabrication method and enhanced pseudocapacitive lithium storage for Sn particles coated SnO_x/ZnO and N-doped carbon nanofibers hybrid could contribute to the practical application of the updated energy storage devices.