Free-standing ternary metallic sulphides/Ni/C-nanofiber anodes for high-performance lithium-ion capacitors

Abstract

Abstract As a promising energy-storage device, the hybrid lithium-ion capacitor coupling with both a large energy density battery-type anode and a high power density capacitor-type cathode is attracting great attention. For the sake of improving the energy density of hybrid lithium-ion capacitor, the free-standing anodes with good electrochemical performance are essential. Herein, we design an effective electrospinning strategy to prepare free-standing MnS/Co4S3/Ni3S2/Ni/C-nanofibers (TMSs/Ni/C-NFs) film and firstly use it as a binder-free anode for hybrid lithium-ion capacitor. We find that the carbon nanofibers can availably prevent MnS/Co4S3/Ni3S2/Ni nanoparticles from aggregation as well as significantly improve the electrochemical performance. Therefore, the binder-free TMSs/Ni/C-NFs membrane displays an ultra-high reversible capacity of 1246.9 mAh g−1 at 100 mA g−1, excellent rate capability (398 mAh g−1 at 2000 mA g−1), and long-term cyclic endurance. Besides, we further assemble the hybrid lithium-ion capacitor, which exhibits a high energy density of 182.0 Wh kg−1 at 121.1 W kg−1 (19.0 Wh kg−1 at 3512.5 W kg−1) and remarkable cycle life.