Construction of Nickel Molybdenum Sulfide/Black Phosphorous 3D Hierarchical Structure Toward High Performance Supercapacitor Electrodes

Abstract

Supercapacitors (SCs) with outstanding versatility have a lot of potential applications in next‐generation electronics. However, their practical uses are limited by their short working potential window and ultralow‐specific capacity. Herein, the facile one‐step in‐situ hydrothermal synthesis is employed for the construction of a NiMo3S4/BP (black phosphorous) hybrid with a 3D hierarchical structure. After optimization, the NiMo3S4/BP hybrid displays a high specific capacitance of 830 F/g at 1 A/g compared to the pristine NiMo3S4 electrode. The fabricated NiMo3S4/BP//NiCo2S4/Ti3C2Tx asymmetric supercapacitor exhibits a better specific capacitance of 120 F/g at 0.5 A/g, which also demonstrates a high energy density of 54 Wh/kg at 1148.53 W/kg and good cycle stability with capacity retention of 86% and 97% of Coulombic efficiency after 6000 cycles. Further from the DFT simulations, the hybrid NiMo3S4/BP structure shows higher conductivity and quantum capacitance, which demonstrate greater charge storage capability, due to enhanced electronic states near the Fermi level. The lower diffusion energy barrier for the electrolyte K+ ions in the hybrid structure is facilitated by improved charge transfer performance for the hybrid NiMo3S4/BP. This work highlights the potential significance of hybrid nanoarchitectonics and compositional tunability as an emerging method for improving the charge storage capabilities of active electrodes.

Facile and scalable fabrication of flexible micro-supercapacitor with high volumetric performance based on ultrathin Co(OH)2 nanosheets

“…To further estimate the capacitive and diffusion-limited contribution to the total capacitance in Co(OH) 2 NS/LSG, the voltammetric scan rate dependence was systematically investigated using Dunn's method (eqn (7) and (8)). 53,54 i ( V ) = k 1 ν + k 2 ν 1/2 i ( V )/ ν 1/2 = k 1 ν 1/2 + k 2 Here, i ( V ) is the current at a specified potential, and k 1 ν and k 2 ν 1/2 represent the current contribution from surface capacitive and diffusion-controlled intercalation processes, respectively. The slope and intercept values from the linear fit of ν 1/2 vs. i ( V )/ ν 1/2 plot correspond to k 1 and k 2 , respectively.…”