High-Performance Energy Storage Device Based on Triple-Shelled Cobalt Gallium Oxide Hollow Spheres and Graphene Wrapped Copper Iron Disulfide Porous Spheres

Demanding more reliable power sources causes a huge development of modern electronic and optoelectronic devices with a high energy density (E N D E ) and exceptional durability. Accordingly, designing modern electrode materials with outstanding structures can improve the construction of a new generation of electronic devices. Transition metal oxides hollow structures (TMOHS) have received considerable attention as appropriate materials for supercapacitors due to their structural properties and electrochemical performances. As a fascinating TMOHS, we make a new highly porous triple-shelled cobalt gallium oxide (CoGa 2 O 4 ) hollow spheres (HTS-CGOHS) with triple narrow shells, and pseudocapacitive graphene wrapped CuFeS 2 hollow spheres (GW@CFSHS) as developed positive and negative electrodes, respectively, in an energy storage device. The HTS-CGOHS electrode shows specific capacitance (SpCa) of 1724.30 F g –1 (239.5 mAh g –1 ) at 1 A g –1 which maintains as high as 1198.40 F g –1 (166.44 mAh g –1 ) at 24 A g –1, and reasonable durableness (96.80% capacity retention at 12 A g –1 ) owing to the low internal resistance, fast kinetics, reversibility, high surface area (104.30 m 2 g –1 ), and numerous active sites. Moreover, the GW@CFSHS advanced negative electrode reveals electrochemical performance comprising a SpCa of 621.20 F g –1 (172.6 mAh g –1 ), rate performance of 58% and excellent durableness, which are superior to that of CuFeS 2 hollow sphere (CFSHS) electrode. According to the electrochemical nature of the as-obtained pseudocapacitive electrode materials, an energy storage device (ESD) based on the HTS-CGOHS as a cathode and GW@CFSHS as an anode was studied. The HTS-CGOHS//GW@CFSHS device shows SpCa of 376.40 F g –1 (153.1 mAh g –1 ), high E N D E of 114.8 W h kg –1, and notable durableness (only 6.3% decrease after 5000 cycles at 6 A g –1 ).