Synthesis of hollow carbon-incorporated NiCoM (M = Mn, Cu, Zn) layered double hydroxide nanocages for hybrid supercapacitors

Nanostructures and compositions are the most crucial aspects in the design of electrode materials with excellent properties for hybrid supercapacitors (HSCs). In this study, bimetallic CoM-zeolitic imidazolate framework-67 (CoM-ZIF-67, M = Mn, Cu, and Zn) derived nanosheet-constructed hollow carbon-incorporated NiCoM layered double hydroxide nanocages (NiCoM-LDH/C) are successfully synthesized via the thermal annealing and subsequent etching/ion-exchange reaction. As a consequence, the NiCoM-LDH/C materials exhibit significantly improved electrochemical performance. Specifically, the optimized NiCoMn-LDH/C electrode possesses an excellent capacity performance of 888.3 C g−1 at 1 A g−1. Moreover, the HSC device assembled by NiCoMn-LDH/C and active carbon delivers a remarkable energy density of 46.5 Wh kg−1 at a power density of 792.5 W kg−1 and possesses superior cyclic stability with about 92.05% capacity retention after 5000 cycles. This work may offer a feasible and effective approach for the synthesis of carbon-incorporated ternary layered double hydroxide nanocage materials for high-performance HSC applications.