Enhanced the energy density of supercapacitors via rose-like nanoporous ZnGa2S4 hollow spheres cathode and yolk-shell FeP hollow spheres anode

Owing to the high demands for fascinating energy storage devices, exploring cost-effective electrodes with exclusive architectures for supercapacitors is crucial; however, the advent of such electrodes to achieve the industrial necessities remains a challenging task. Herein the design and characterization of roselike nanoporous ZnGa2S4 hollow spheres (RN-ZGSHS) are described. This structure with the surface area of 71.7 m(2) g(-1) can provide a capacity of 358.4 mAh g(-1) at 2 A g(-1) and capacity of 260.2 mAh g(-1) at 50 A g(-1), as well as significant robustness of 98.4%. To achieve higher energy density in the asymmetric energy storage device, a yolk-shell nanoporous iron phosphide hollow spheres (YS-FePHS) as a negative electrode is also designed. The designed anode electrode with a quasi-rectangular-like character can deliver a capacity of 117.5 mAh g(-1) at 1 A g(-1) and maintains a high capacity of 65.8 mAh g(-1) at 25 A g(-1), with satisfactory robustness of 89.9%. Ultimately, the constructed asymmetric device (RN-ZGSHS//YS-FePHS) depicts the ED of 72.78 W h kg(-1) at a power density (PD) of 800 W kg(-1), while keeps a high energy density of 49.13 W h kg(-1) at a power density of 64148.53 W kg(-1).