Core-shell structured SnSe@C microrod for Na-ion battery anode

Abstract The SnSe nanoparticles encapsulated in the carbon nanofibers (SnSe@C) with microrod morphology and core-shell structure are prepared by electrospinning and annealing process, and investigated as anode materials for sodium ion batteries. Benefiting from this unque structure, the SnSe@C can deliver a reversible capacity of 283.8 mAh g−1 after 500 cycles at a high current density of 1.0 A g−1. The sodium ion storage mechanisms of SnSe are further characterized by ex-situ X-ray diffraction, high-resolution transmission electron microscope and selected area electron diffraction measurements. Besides, the excellent electrochemical performance of the electrodes is investigated by pseudocapacitance and in situ electrochemical impedance spectroscopy measurements. This work may provide a new avenue for synthesis of metal selenides with core-shell structure and a good idea for studying the kinetics process.