ZnSe with nanostructure embedded in graphene nanosheets with elevated electrochemical performance for anode material of sodium ion battery

Traditional metal selenide was used as sodium ion battery anode on account of its high specific capacity and large layer spacing. Here, ZnSe/rGO composites are synthesized through a facile one-step hydrothermal method using relatively environmentally friendly raw materials. The obtained ZnSe nanoparticles with a diameter of about 50 nm, which evenly distributed on the three-dimensional graphene sheet. Electrochemical test results show improved performance, under a current density of 100 mA g−1, the capacity can still remain 276.6 mA h g−1 after 100 cycles. For rate performance, when the current density are under 0.1, 0.2, 0.5, 1, 2, 5 and 10 A g−1, the capacity can remain 411.6, 385.9, 340.1, 293.9, 239.4, 179.2 and 119.4 mA h g−1, respectively. Furthermore, under a large current density of 500 mA g−1, it can remain a reversible capacity of 119.4 mA h g−1. In addition, the calculation of pseudocapacitance shows that it is helpful to achieve pleasing rate capability and long cyclic stability. As a result of its high specific surface area and enhanced electronic conductivity, an improved performance can be obtain, furthermore can well alleviate the volume expansion of the composite. ZnSe/rGO composites are synthesized through a facile one-step hydrothermal method. The obtained ZnSe nanoparticals with a diameter of about 50 nm are evenly distributed on the three-dimensional graphene sheet. Electrochemical test results show improved performance, under a current density of 100 mA g−1, the capacity can still remain 276.6 mA h g−1 after 100 cycles. For rate performance, when the current density are under 0.1, 0.2, 0.5, 1, 2, 5, 10 A g−1, the capacity can remain 411.6, 385.9, 340.1, 293.9, 239.4, 179.2 and 119.4 mA h g−1, respectively. [Display omitted] •ZnSe/rGO composites are synthesized through a facile one-step hydrothermal method.•ZnSe nanoparticals with a diameter of about 50 nm are evenly distributed on the three-dimensional graphene sheet.•The capacity for ZnSe/rGO composites can still remain 276.6 mA h g−1 after 100 cycles.•As-prepared ZnSe/rGO composites exhibits good rate performance (119.4 mA h g−1 at 10 A g−1).