Construction of Double-Shell Basic Cobalt/Nickel Carbonate Microspheres via MOFs Etching Strategy for Boosting Aqueous Supercapacitor Performances

• Key Words:HYBRID SUPERCAPACITORS; ELECTRODE MATERIAL; NANOSHEET ARRAYS; ENERGY; CLOTH; NI; FABRICATION; NANOTUBES; HYDROXIDE; DESIGN
• Abstract:Recently, the anion-functioned or anion-doped Co/Ni hydroxide materials have attracted widespread concern in the scientific field due to their dramatically enhanced performances in energy storage and conversion application. Herein, we reported effective metal-organic frameworks (MOFs) etching strategy to construct the MOFs derived cobalt-nickel hydroxide carbonate (CNHC) double -shell microspheres for boosted supercapacitor performance. The etching process is driven by the CO32- and OH- anions via the hydrolysis of urea, and the organic ligand in MOFs is gradually substituted by the CO32- and OH- anions to form the thermodynami-cally stable Co/Ni(CO3)x(OH)y phase. Then, the hierarchical double -shell structure constructed by a self-supported Co/Ni(CO3)x(OH)y nanosheet is accessed by the Ostwald ripening process, which provides abundant channels and abundant accessible active centers for enhanced electrochemical reaction kinetics. The optimized CNHC-12h electrode demonstrates a high specific capacitance of 1233.6 F g-1 at 1 A g-1 and outstanding rate performance of 80% when the current density is expanded ten times. In addition, the hybrid supercapacitor device assembled by CNHC-12h//AC achieves the high energy density of 41.8 Wh kg-1 at the power density of 0.8 kW kg-1 and can operate the thermometer normally for 20 min with 5 s charging time. The construction of MOFs derived basic carbonate materials will provide a possibility to synthesize high capacitance performance anions-functioned hydroxide electrode materials for energy storage devices and practical application.
• Volume:6
• Issue:18
• Translation or Not:no