High-performance battery-type Fe1-xS@CFs anode for all-solid-state battery-type asymmetric supercapacitor with high energy density and wide working temperature range

Abstract Pseudo-capacitive materials with high performance are always combined with carbon-based materials applying for supercapacitors, which can realize satisfactory properties of energy storage while excellent cycle life. Enhancing electrochemical performance of anodes following the method is an effective method to get high energy densities. Herein, Fe1-xS grown on carbon nanofibers (Fe1-xS/CFs) through electrospinning and calcination approach, possesses excellent electrochemical properties when it serves as the anode for asymmetric supercapacitors. The specific capacity of which can reach up to 238 mAh g−1 (1 A g−1) while remain 95.3 mAh g−1 at 15 A g−1. The retention rate of the anode can retain 78.5% after 5000 cycles. Considering high performance of anode, NiCo2S4/NCTs with a high specific capacity of 203 mAh g−1 (1 A g−1) was selected as the cathode applying for all-solid-state battery-type asymmetric supercapacitor to get high energy density. Benefitting from excellent properties of both anode and cathode, as-fabricated all-solid-state battery-type asymmetric supercapacitor possesses high energy density of 55.4 Wh kg−1 at the power density of 882 W kg−1 with remarkable cyclic performance (80.6% after 5000 cycles). More important, all-solid-state battery-type asymmetric supercapacitor NiCo2S4/NCTs//Fe1-xS/CFs-5 can work with a wide temperature range (−10 to 60 °C), which can display a specific capacity of 40.4 mAh g−1 at 1 A g−1 in −10 °C and 112.3 mAh g−1 in 60 °C. All these results indicate that as-fabricated NiCo2S4/NCTs//Fe1-xS/CFs-5 battery-type asymmetric supercapacitor possesses great potential for future applications.