Bimetallic metal-organic framework derived porous NiCo2S4 nanosheets arrays as binder-free electrode for hybrid supercapacitor

Recently, metal-organic frameworks (MOFs) derived materials in the form of bulk powders with attractive chemical and structural properties show broad application in electrochemical energy storage. Bimetallic materials-based MOFs usually show better electrochemical properties than that of monometallic derivatives, while achieving the bimetallic MOFs-derived materials on current collector as a binder-free electrode is still a challenge. Here we report a new approach to directly obtain a binder-free electrode of bimetallic MOFs-derived NiCo2S4 nanosheet arrays on nickel foam (NF) substrate. The porous NiCo2S4 nanosheet arrays providing fast electrolyte permeation and rich electrochemical active sites, show an excellent specific capacity of 1354.4 C g(-1), high rate performance, and outstanding cycling stability of 82.6% retention after 10,000 cycles. A hybrid supercapacitor assembled with the as-obtained binder-free electrode as a cathode and active carbon as an anode, exhibits high energy density of 49.1 Wh kg(-1) at a power density of 375 W kg(-1) and superior cycling stability of 94.5% retention after 10,000 cycles. These results offer a novel and general approach to construct binder-free electrode materials with advanced performance for the portable and practical energy storage device.

Automated summary

A new approach of obtaining a binder-free electrode of bimetallic MOFs-derived NiCo2S4 nanosheet arrays on nickel foam substrate has been reported, showing excellent specific capacity, high rate performance, and outstanding cycling stability. The hybrid supercapacitor assembled with this electrode exhibits high energy density and superior cycling stability, offering a novel and general approach for constructing advanced electrode materials for energy storage devices.