CuCo2S4 nanotubes on carbon fiber papers for high-performance all-solid-state asymmetric supercapacitors

In this study, CuCo 2 S 4 directly grown on carbon fiber papers (CFP) were prepared by a low-cost hydrothermal method. We also studied the influence of two different sulfur sources on the morphology and performance of CuCo 2 S 4 . Compared to TAA as sulfur source, the performance and morphology of CuCo 2 S 4 by Na 2 S·9H 2 O are better. The CuCo 2 S 4 –Na 2 S nanotubes possess irregular diameters from 100 to 200 nm. An electrode made of the synthesized CuCo 2 S 4 –Na 2 S nanotubes/CFP composite exhibits a maximum specific capacitance of 456 F g −1 at 1 A g −1 and 83% of capacitance retention after 5000 cycles at 5 A g −1 . The synthesized CuCo 2 S 4 –Na 2 S/CFP is used to construct an all-solid-state asymmetric supercapacitor (ASC) as the positive electrode, while and the negative electrode is made of a Fe 2 O 3 /reduced graphene oxide (rGO) composite on Ni foam. This asymmetric device has delivered an energy density of 50 W h kg −1 and a power density of 700 W kg −1 at an operating voltage of 1.5 V. It retains a long cycling life—78.2% capacity retention ratio after 5000 cycles. This work demonstrates the feasibility of the CuCo 2 S 4 –Na 2 S nanotubes in the applications of high-performance supercapacitors.