Facile Electrodeposition of Mn-CoP Nanosheets on Ni Foam as High-Rate and Ultrastable Electrodes for Supercapacitors

Abstract

As the combined merits of structures and compositions could have a great impact on electrodes, we synthesized manganese-doped cobalt phosphide nanosheets on Ni foam (Mn-CoP/NF) via a facile electrodeposition method. The synergistic effect between Mn and Co ions provides mixed valence states and adjusts the bandgap for accelerating the high redox reaction kinetics and improving the electron mobility and electrical conductivity. Meanwhile, the nanosheet structure provides rich electroactive sites and excellent structural stability for facilitating the electron transfer and resisting structural damage. As expected, the obtained Mn-CoP/NF electrode acquired a superior specific capacity (456 C g–1 at 0.5 A g–1), an excellent rate performance (77.4% capacity retention at 10 A g–1), and an excellent cyclability (89.0% capacity retention after 20,000 cycles). The Mn-CoP/NF//AC asymmetric supercapacitor (ASC) delivers a high energy density (14.82 W h kg–1 at 312 W kg–1) and long-term durability (87.7% capacity retention after 20,000 cycles). Moreover, two ASC devices can be used to light an LED for 6 min, demonstrating ASC’s promising practical applications.

Metal–organic framework-derived hollow Co9S8 nanotube arrays coupled with porous FeCo–P nanosheets as an efficient electrode material for hybrid supercapacitors

“…6(g) and Table S2 †). [73][74][75][76][77][78][79] Furthermore, the cycling feature of NF/CS4-FCP30jjNF/AC is recorded for 6500 cycles of uninterrupted GCD tests at 5 A g −1 (Fig. 6…”

Construction of thickness-controllable bimetallic sulfides/reduced graphene oxide as a binder-free positive electrode for hybrid supercapacitors

“…the ionic resistance of the substrate, electroactive material, and electrolyte interface) was estimated from the left intercept of the semi-circle region. 86 The charge transfer resistance ( R ct ) is conducted from the diameters of semi-circles for analyzing the faradaic kinetics. 87 The ion diffusion resistance ( R w ) is represented by the straight line slope that depicts the transfer and diffusion kinetics of electrolytes in the electrodes.…”

“…At low scan rates, the diffusive behaviour is more prominent because ions have enough time to interact with the surface of the electrode while at high scan rates promote the capacitive behaviour. 90 The ratios of capacitive/diffusion-controlled contributions might be conducted using Dunn's approach depending on the redox current of the CV curve at a certain potential ( i ( V )) as follow: 86 i ( V ) = k 1 ν + k 2 ν 1/2 …”

Metal Phosphides as Promising Electrode Materials for Alkali Metal Ion Batteries and Supercapacitors: A Review

“…The capacitance performance of MnCoP is not quite outstanding, but the simple electrodeposition process has advantages in cost and environmental friendliness. [199] It is feasible to replace Co element in bimetal phosphides while maintaining high capacitance performance. Sharkawy et al fabricated Ni-Cu-P//NF by one-pot solvothermal method.…”