Composites of Bi2Se3 nanoparticles and FeSe2 nanoparticles for supercapacitor anode materials

The low capacity of negative electrode materials for supercapacitors limits their practical applications. In this study, the bimetallic selenides Bi 2 Se 3 /FeSe 2 were efficiently prepared by a convenient one-step microwave method. The attributes of nanoparticles such as surface morphology, crystal structure, elemental valence, and distribution regions were verified by a series of characterization tools. The composite electrode exhibits high electrochemical performance in the 1.2 V negative potential window. The capacitance of the Bi 2 Se 3 /FeSe 2 electrode is 274 mAh g −1 at 1 A g −1 . These results indicate that Bi 2 Se 3 /FeSe 2 holds great potential for supercapacitor anode materials. In particular, the asymmetric water-based supercapacitor dual-electrode device (NiSe/NiTe 2 //Bi 2 Se 3 /FeSe 2 ) shows an impressive power/energy density of 56.25 Wh kg −1 at 774.67 W kg −1 . The capacitance of ASC is reduced by 20.10 % and the coulomb efficiency is maintained at 99.45 % over 3000 cycles.