NiCo2O4 nanowire-supported NiCoMnS4 nanosheets on carbon cloth as a flexible cathode for high-performance aqueous supercapacitors

In this paper, we report a self-supported flexible electrode consisting of NiCoMnS4 nanosheets on NiCo2O4 nanowires, denoted as NiCo2O4@NiCoMnS4 ([email protected]) prepared by the hydrothermal growth (NiCo2O4) and the following electrodeposition (NiCoMnS4) on a carbon cloth (CC) substrate. The electrode delivers a high specific capacity of 4836 mF cm–2 at 1 mA cm–2 and excellent rate performance, i.e., 3820 mF cm–2 at 10 mA cm–2 and 2820 mF cm–2 even at 60 mA cm–2. An aqueous asymmetric supercapacitor (AASC) assembled using [email protected] on CC as the cathode, activated carbon on CC as the anode and 2 M KOH as the electrolyte delivers a high energy density of 0.399 mWh cm–2 at 0.85 mW cm–2 and excellent cycle stability with ∼81.2% capacity retention after 20000 cycles at a high current density of 20 mA cm–2. In view of the excellent performance and facile preparation, this study is believed to provide a valuable exploration of developing high-performance electrodes and AASCs.