A facile dissolved and reassembled strategy towards sandwich-like rGO@NiCoAl-LDHs with excellent supercapacitor performance

Metal organic frameworks hold great potential for high-performance supercapacitors owning to ultrahigh specific surface area and exceptional porosity. Nevertheless, the poor charge transfer kinetics and chemical instability in alkali medium still remain a significant challenge. Herein, a facile dissolved and reassembled strategy towards sandwich-like rGO@NiCoAl-LDHs is proposed to address these drawbacks. NiAl-LDHs can be used as an accumulator to accommodate and reassemble the cobalt ions dissolved from ZIF-67. Graphene could facilitate charge transfer and provide more active sites. Meanwhile, the sandwich-like structure could shorten the transfer distance of electrons and reduce the diffusion resistance of electrolyte. The electrochemical performance is drastically improved due to the enhancement of intrinsic activity reassembling from sandwich-like rGO@ZIF-67@NiAl-LDHs to rGO@NiCoAl-LDHs during cycle process. The electrode material delivers a superior specific capacity of 2291.6 F/g at 1 A/g in a three-electrode configuration. The assembled rGO@NiCoAl-LDHs//AC fulfills a high energy density of 91.4 Wh/kg at a power density of 875 W/kg. In a word, this dissolved and reassembled strategy could possess the huge prospect for energy-related devices.