Cactus‐Like NiCoP/NiCo‐OH 3D Architecture with Tunable Composition for High‐Performance Electrochemical Capacitors

Abstract

To effectively enhance the energy density and overall performance of electrochemical capacitors (ECs), a new strategy is demonstrated to increase both the intrinsic activity of the reaction sites and their density. Herein, nickel cobalt phosphides (NiCoP) with high activity and nickel cobalt hydroxides (NiCo-OH) with good stability are purposely combined in a hierarchical cactus-like structure. The hierarchical electrode integrates the advantages of 1D nanospines for effective charge transport, 2D nanoflakes for mechanical stability, and 3D carbon cloth substrate for flexibility. The NiCoP/ NiCo-OH 3D electrode delivers a high specific capacitance of ≈1100 F g −1 , which is around seven times higher than that of bare NiCo-OH. It also possesses ≈90% capacitance retention after 1000 charge-discharge cycles. An asymmetric supercapacitor composed of NiCoP/NiCo-OH cathode and metal-organic framework-derived porous carbon anode achieves a specific capacitance of ≈100 F g −1 , high energy density of ≈34 Wh kg −1 , and excellent cycling stability. The cactus-like NiCoP/NiCo-OH 3D electrode presents a great potential for ECs and is promising for other functional applications such as catalysts and batteries.

Construction of CoP/NiCoP Nanotadpoles Heterojunction Interface for Wide pH Hydrogen Evolution Electrocatalysis and Supercapacitor

“…[10,15,47,[49][50][51][52] And the rich mixed valenced Ni, Co, and P atoms benefit the formation of ionic and electronic defects, enhancing the electrochemical properties. [10,15,47,[49][50][51][52] And the rich mixed valenced Ni, Co, and P atoms benefit the formation of ionic and electronic defects, enhancing the electrochemical properties.…”

Carbon Cloth‐based Hybrid Materials as Flexible Electrochemical Supercapacitors

“…The as‐prepared electrode has integrated advantages of the 1D core which acts as hyper‐channel for electron transport, 2D shell for short of diffusion distance for ions and charge carriers which improves cyclic stability. The intimate contact between carbon cloth substrate and active materials provides good mechanical adhesion and electrical connection thereby improving the conductivity which accelerates charge transport resulting in lowering of overall resistance . The asymmetric supercapacitor fabricated by using NiCoP@NiCoP@CC anode and activated carbon cathode delivered high power density outputs of 750 and 7500 W/kg at energy densities 34.8 and 18.5 Wh/kg.…”

In Situ Formation of Co9S8 Quantum Dots in MOF‐Derived Ternary Metal Layered Double Hydroxide Nanoarrays for High‐Performance Hybrid Supercapacitors

“…Therefore, numerous effective strategies based on LDHs, including the reconstruction of transition metal compounds, adjusting the proportion of metal ions, and carbon doping, have been developed to explore higher redox activity with abundant active sites. Notably, modified LDHs, such as NiCo‐LDH/MMoS x heteronanostructures, CNT@NiCo‐LDH, cactus‐like NiCoP/NiCo‐OH, H‐3DRG@NiCo 2 S 4 nanowires, and core–shell structural (Ni, Co) Se 2 /NiCo‐LDH, have displayed novel structural features and considerable exposed active sites. Nevertheless, the derived chemical species on the outer surfaces of LDHs impair the interlayer structure of LDHs to some extent and lead to pore blockage issues, which can decrease the structural stability of materials and increase the mass transport resistance.…”