Effectively constructed by the interior and interface coexisting design of cobalt‐doped NiFe 2 S 4 nanosheets for high‐performance supercapacitors

The doped metal materials/transitional metal sulfides have been regarded as unique superior-efficient electrodes because of their high Faradic activities. Nevertheless, the aggregation limits and poorer rate performances critically hinder the supercapacitors (SCs). Herein, the interior and interface coexisting design of cobalt-doped NiFe2S4 nano sheets on nickel foam (Co- NiFe2S4) was constructed and synthesized via a two-step hydrothermal approach. The Co- NiFe2S4 served as the skeleton supports and conductive pathways and supplies plentifully coordination ions to block the aggregations and enhance the nanostructured stabilities. The results are auspicious: the electrodes showed quick ion and electron transportation rates and many electroactive surface regions, evidencing their superior electrochemical performances. Regarding the superiority in physical and chemical characterizations, the Co-NiFe2S4 composite was attracted more attention than other SCs applications because of their suitable morphology for electron/ion transportations, safety, numerous redox-active sites with varied oxidational states, lower-cost with nontoxicity, and high charge-discharge rates in electrochemical activities. Especially, the Co-NiFe2S4 electrode demonstrated superior electrochemical performance of specific capacity of 1075.4 C g−1 (2329.6 F g−1) at 1 A g−1 and capacity retention of around 96.8% after 5000 long-cycles at 3 A g−1. These results signify that the ternary construction, Co-NiFe2S4 composite is a superior capacitor at higher stabilities with a very less loss in capacity retentions, which is a promising electrode as a nanomaterial for high-performance SCs that could be applicable in the commercial field soon.