Construction of CoNi_(2)S_(4) nanocubes interlinked by few-layer Ti_(3)C_(2)T_(x) MXene with high performance for asymmetric supercapacitors

摘要

Both MXene and zeolitic imidazolate framework(ZIF)derivatives are tend to agglomerate during the compound process,which adversely affects their electrochemical properties.To alleviate this phenomenon,fewlayer MXene was stripped by mechanical method,and electrostatic self-assembly with ZIF-67 in the presence of cationic surfactants.Furthermore,CoNi_(2)S_(4)/MXene composite was synthesized by the facile hydrothermal reaction.CoNi_(2)S_(4)well retained the cube frame structure of the ZIF-67 with the sagging outer frame and rough surface.In the composite,CoNi_(2)S_(4)nanocubes were interlinked by MXene nanosheets,which can effectively improve the structural stability and make full use of the active surface.CoNi_(2)S_(4)/MXene composite electrode exhibits an outperforming specific capacitance(751 C·g^(-1)at 1 A·g^(-1)),far higher than that of pure CoNi2S4(600 C·g^(-1)at 1 A·g^(-1)).An asymmetric supercapacitor(CoNi_(2)S_(4)/MXene//reduced graphene oxide(RGO))assembling delivers high energy density of 33.8 Wh·kg^(-1)and excellent cycling performance.This study indicates the potential of MXene/ZIF derivatives in the application of supercapacitor.