MOF-derived (Ni, Co)Se2 @CoP/CNFs@CF with enhanced reaction kinetics by heterointerface engineering for high-performance hybrid supercapacitors

Abstract

Ni/Co selenide (NCSe), which has a high theoretical capacity and a lot of redox activity, is a candidate for high-performance supercapacitor electrode materials. With its poor reaction kinetics, it performs electrochemically much less efficiently than it should. Herein, we first synthesized MOF-derived zero-dimensional (0D)/two-dimensional (2D) (Ni, Co)Se2 @CoP/CNFs@CF (carbon and nitrogen framework) hierarchical heterogeneous nanosheet arrays. The charge transport is accelerated by the Coulomb forces of the built-in electric field created by the electron rearrangement at the heterointerface of (Ni, Co) Se2 @CoP/CNFs@CF. Moreover, the 0D/2D micro-nanostructure promotes interlayer shuttling and the penetration of electrolyte ions while combining the benefits of 0D and 2D materials. The two synergistically accelerate the reaction kinetics of the electrode. As expected, (Ni, Co)Se2 @CoP/CNFs@CF has an excellent specific capacity (431.7 mAh g−1, 1 A g−1). In addition, the hybrid supercapacitor (Ni, Co)Se2 @CoP/CNFs@CF//AC (activated carbon) has an ultra-high energy density (85.31 Wh kg−1, 800 W kg−1) and cycling stability (10,000 cycles, 113.72%). This is the P/Se hybrid metal compound electrode's best electrochemical performance to date. This work offers a method for fabricating electrodes with heterostructures for high energy density hybrid supercapacitors by enhancing the attributes of the electrode structure and interface.