Redox Tuning in Crystalline and Electronic Structure of Bimetal–Organic Frameworks Derived Cobalt/Nickel Boride/Sulfide for Boosted Faradaic Capacitance

Abstract

The development of efficient electrode materials is a cutting‐edge approach for high‐performance energy storage devices. Herein, an effective chemical redox approach is reported for tuning the crystalline and electronic structures of bimetallic cobalt/nickel–organic frameworks (Co‐Ni MOFs) to boost faradaic redox reaction for high energy density. The as‐obtained cobalt/nickel boride/sulfide exhibits a high specific capacitance (1281 F g−1 at 1 A g−1), remarkable rate performance (802.9 F g−1 at 20 A g−1), and outstanding cycling stability (92.1% retention after 10 000 cycles). An energy storage device fabricated with a cobalt/nickel boride/sulfide electrode exhibits a high energy density of 50.0 Wh kg−1 at a power density of 857.7 W kg−1, and capacity retention of 87.7% (up to 5000 cycles at 12 A g−1). Such an effective redox approach realizes the systematic electronic tuning that activates the fast faradaic reactions of the metal species in cobalt/nickel boride/sulfide which may shed substantial light on inspiring MOFs and their derivatives for energy storage devices.

Ultrathin Ni(OH)2 layer coupling with graphene for fast electron/ion transport in supercapacitor

“…EDLCs store energy by reversible ion adsorption at the electrolyte/electrode surface, which highly depends on the specific surface area. In contrast, pseudocapacitors work through Faradaic redox reactions both on and near the surface of the electroactive materials, which usually have larger capacitance than that of EDLCs [9][10][11]. However, the relatively low energy density is a common bottleneck for both types of supercapacitors, severely limiting their widespread applications.…”

Design of Ultra‐Microporous Carbons by Interpenetrating MF Prepolymer into PAAS Networks at Molecule Level for Enhanced Electrochemical Performance

“…As revealed in Figure a, UMC‐IPNs, PC‐MFB and PC‐MF electrodes show similar cyclic voltammetry (CV) curves closed to the rectangle, suggesting a good electric double layer capacitance (EDLC) behavior . The difference is that the CV area of UMC‐IPNs is much larger than the area of PC‐MFB and PC‐MF, which means the highest specific capacity of it . Subsequently, the CV of UMC‐IPNs was carried out from 5 to 200 mV s −1 (Figure S3a).…”

A Biomimetic‐Mineralization‐Inspired Hybrid Mesocrystal with Boosted Lithium Storage Properties

“…As a new high‐energy battery successfully developed in the 20 th century, LIBs have been widely used to power portable electronics and electrical vehicles (e. g. mobile phones, portable computers, and video cameras, etc.). To meet the demand of higher capacity and better rate capability for next‐generation LIBs, people have put considerable effort on searching for promising alternative electrode materials . Among the currently emerging candidates, iron oxides (Fe 2 O 3 and Fe 3 O 4 ) have drawn intensive attention due to their high theoretical capacity of about 1000 mAh g −1 , environmental benignity, natural abundance, low cost, high corrosion resistance, and several other appealing advantages (e. g. design flexibility, more beneficial lithium insertion and the non‐inflammability) .…”

“…To boost their lithium storage properties, the major strategies developed to date are focusing on following two pathways: (i) constructing iron oxide electrodes to porous and/or hollow micro‐/nanostructures with plenty of voids to relieve the strain of volume change during the charge/discharge cycling process; additionally, such nanostructures can expose more active sites, allowing for fast diffusion of Li + ions, and can also guarantee a full contact between electrode and electrolyte; (ii) to integrate carbonaceous materials (e. g. graphene, carbon nanotubes, amorphous carbon, and their derivatives) into iron oxide to form hybrid nanostructures. As such, the electronic conductivity can be improved and may also serve to buffer the volume strain .…”