Hollow NiCo₂S₄ Nanospheres Hybridized with 3D Hierarchical Porous rGO/Fe₂O₃ Composites toward High‐Performance Energy Storage Device

Abstract

Hierarchical hollow NiCo2S4 microspheres with a tunable interior architecture are synthesized by a facile and cost‐effective hydrothermal method, and used as a cathode material. A three‐dimensional (3D) porous reduced graphene oxide/Fe2O3 composite (rGO/Fe2O3) with precisely controlled particle size and morphology is successfully prepared through a scalable facile approach, with well‐dispersed Fe2O3 nanoparticles decorating the surface of rGO sheets. The fixed Fe2O3 nanoparticles in graphene efficiently prevent the intermediates during the redox reaction from dissolving into the electrolyte, resulting in long cycle life. KOH activation of the rGO/Fe2O3 composite is conducted for the preparation of an activated carbon material–based hybrid to transform into a 3D porous carbon material–based hybrid. An energy storage device consisting of hollow NiCo2S4 microspheres as the positive electrode, the 3D porous rGO/Fe2O3 composite as the negative electrode, and KOH solution as the electrolyte with a maximum energy density of 61.7 W h kg−1 is achieved owing to its wide operating voltage range of 0–1.75 V and the designed 3D structure. Moreover, the device exhibits a high power density of 22 kW kg−1 and a long cycle life with 90% retention after 1000 cycles at the current density of 1 A g−1.

Biomass‐Derived 3D Carbon Aerogel with Carbon Shell‐Confined Binary Metallic Nanoparticles in CNTs as an Efficient Electrocatalyst for Microfluidic Direct Ethylene Glycol Fuel Cells

“…[29,44] It amplifies the accessibility of the electrolyte into the electrode via the porous carbon channels and framework, which promote the mass transport of ions/electrons with lower resistance. [29,44] It amplifies the accessibility of the electrolyte into the electrode via the porous carbon channels and framework, which promote the mass transport of ions/electrons with lower resistance.…”

Ultrafast Laser Pulses Enable One‐Step Graphene Patterning on Woods and Leaves for Green Electronics

“…Graphene offers great potential for electronics, optoelectronics, and energy storage applications due to its high charge carrier mobility, large specific surface area, good chemical/physical stability, and biocompatibility . Graphene has been synthesized in various ways such as epitaxial growth on silicon carbide via sublimating Si atoms, chemical or solvothermal reductions of exfoliated graphite oxides, and chemical vapor deposition (CVD) from C‐containing gases . These methods are, however, still away from green manufacturing fulfilling all five criteria listed above .…”

Explicating the Sodium Storage Kinetics and Redox Mechanism of Highly Pseudocapacitive Binary Transition Metal Sulfide via Operando Techniques and Ab Initio Evaluation

“…As a promising family of materials owing to their large interlamellar distance, open‐structured and electronic conductivity, transition metal sulfides (TMS) such as molybdenum, tungsten, nickel, and cobalt disulfides, have garnered considerable research emphasis recently. In comparison to TMS, binary metal sulfides (BMS) usually display even richer ionic/redox reactivity, which can result in enhanced sodiation capacity and electrochemical response of the Na‐ions due to richer ionic reactive channels, i.e., larger pseudocapacitive contribution with intrinsic faradaic capacitive behavior. Due to this unusual advantage, the choice of adopting BMS anodes provide adequate solution platform for facilitation of much heavier Na‐ions kinetics for faster rate response.…”