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

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 CO3 2– and OH– anions via the hydrolysis of urea, and the organic ligand in MOFs is gradually substituted by the CO3 2– and OH– anions to form the thermodynamically 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.

Solvent-Assisted Morphology-Induced Nickel Metal–Organic Framework as a Highly Efficient Electrode for Energy Storage Application

“…The energy density ( E ) and power density ( P ) of the device have been calculated and compared with recently reported literature, as shown in Figure f. Compared to other reported MOF-related literatures, ,− the fabricated (N-0.5//AC) device shows superior energy storage and delivering capacity.…”

Sodium‐Substituted Tungsten Oxide Nanoflowers: An Efficient Electrode Enhancing the Pseudocapacitive Storage in Aqueous Asymmetric Supercapacitors

“…The series resistance (R s ) value of 0.049 Ω signifies higher conductivity, attributed to a well‐designed and optimized asymmetric cell with favorable performance characteristics. The charge transfer resistance (R ct ) value of 0.023 Ω suggests an excellent interface between electrode and electrolyte in an aqueous medium [43,44] . Lastly, the Warburg impedance (Z w ) represents the impedance associated with diffusion processes within the electrode materials.…”

“…The charge transfer resistance (R ct ) value of 0.023 Ω suggests an excellent interface between electrode and electrolyte in an aqueous medium. [43,44] Lastly, the Warburg impedance (Z w ) represents the impedance associated with diffusion processes within the electrode materials. The Z w value of 0.072 Ω indicates the fast diffusion mechanism of proton within the materials.…”

NiCo2S4/rGO composite electrode material derived from CO-based MOFs for high-efficiency hybrid supercapacitors

“…Therefore, the modi cation and modi cation on this basis are essential. In recent years, MOFs (Metal-organic Frameworks), as a new electrode material, have attracted wide attention in the eld of supercapacitors [20][21][22][23]. This material has high porosity and good chemical stability, and it is precisely because of this property that it is often used as a template for nanomaterials, which plays an important role in improving the speci c capacity and energy density of materials [24,25].…”