Phosphorous-containing oxygen-deficient cobalt molybdate as an advanced electrode material for supercapacitors

Abstract

The intrinsically poor electrical conductivity and insufficient number of electrochemically active sites of transition-metal oxides hamper their wide application in high-performance supercapacitors. Herein, we demonstrate an effective strategy of creating phosphorus-containing cobalt molybdate (CoMoO 4) with oxygen vacancies (P-CoMoO 4-x) on nickel foam for use as a supercapacitor electrode. Experimental We have demonstrated a facile strategy for creating O vacancies and incorporating P atoms in P-CoMoO 4-x nanosheets on conductive Ni foam. Experimental and theoretical studies provide insight into the effect of the introduction of P and of O vacancies on structural and electrical properties of P-CoMoO 4-x. Moreover, P incorporation into the P-CoMoO 4-x lattice induces reduction in bond energy of CoO and the formation of Mo species with a lower oxidation state, resulting in substantially enhanced redox reaction kinetics and electrochemical performance. 4 Accordingly, the optimized P-CoMoO 4-x achieves a high specific capacity of 1368 C g −1 at a current density of 2 A g −1 , and excellent electrochemical stability. The asymmetric supercapacitor P-CoMoO 4-x //AC delivers superior energy densities of 58 W h kg −1 at a power density of 850 W kg −1 .

Phosphorus‐Functionalized Fe2VO4/Nitrogen‐Doped Carbon Mesoporous Nanowires with Exceptional Lithium Storage Performance

“…The electrochemical behaviors of the Fe 2 VO 4 /NCMNWs and P‐Fe 2 VO 4 /NCMNWs were investigated through the comparison of the first cycle CV curves at 0.1 mV s −1 (Figure A). It is clear that the integrated CV curve area and peak current densities of P‐Fe 2 VO 4 /NCMNWs are larger than those of Fe 2 VO 4 /NCMNWs, indicating that the introduction of phosphorus in carbon layer and Fe 2 VO 4 can remarkably boost its electrochemical reaction activity . The anodic peaks of P‐Fe 2 VO 4 /NCMNWs are slightly different from those of Fe 2 VO 4 /NCMNWs, as the P dopant would influence the overall chemical states of the Fe and V, which is confirmed by the XPS characterization.…”

Phosphorus dual-site driven CoS2@S, N co-doped porous carbon nanosheets for flexible quasi-solid-state supercapacitors

“…The long-term cycling stability of P-CoS2@P, S, N-C is also superior to that of most of the reported Co-based nanostructures. 12,50 The CoS2@S, N-C and P-CoS2@P, S, N-C electrodes deliver nearly 100% Coulombic efficiency after cycling (Fig. S14), which shows their high electrochemical reversibility.…”

“…9 To address these issues, scholars have adopted some feasible strategies, such as designing distinct structure architectures grown on conductive substrates, reducing the particle size, hybridizing with carbonaceous materials, and/or developing defect engineering. [10][11][12] Metal-organic framework (MOF)-derived metal sulfide@carbon hybrids have gained great attention in electrochemical energy storage because they inherit the structural advantages of the precursors of the MOFs, such as well-defined porosity, ordered tunnels, and high specific surface area, 10,13 and merge the features of high charge storage capability of metal sulfides and good rate performance of carbonaceous materials. 10,14 Compared with conventional metal sulfide/surface-coated carbon planar hybrids, MOF-derived encapsulated hybrids with strong bridged bonds between the carbon matrix and active materials are more effective in maximizing the exposed active sites and improving cycling durability.…”

Carbon Cloth Modified with Metal‐Organic Framework Derived CC@CoMoO4‐Co(OH)2 Nanosheets Array as a Flexible Energy‐Storage Material

“…For example, Liu et al. synthesized phosphorus‐containing CoMoO 4 on nickel foam through a hydrothermal method with post‐annealing treatment and reported a high specific capacitance of 1368 C g −1 at 2 A g −1 . Fang et al.…”

“…For example, Liu et al synthesized phosphorus-containing CoMoO 4 on nickel foam through a hydrothermal method with post-annealing treatment and reported a high specific capacitance of 1368 C g À 1 at 2 A g À 1 . [13] Fang et al proved that the hierarchical porous CoMoO 4 using one-step hydrothermal method possess a specific capacitance of 1628.1 C g À 1 at 2 mA cm À 2 . [14] Nti et al described the fabrication of NiMoO 4 /CoMoO 4 nanorods reached 1445 F g À 1 at 1 A g À 1 .…”