Controlled Synthesis And Energy-storage Properties Of Copper-cobalt Bimetallic MOF Derived Materials

Supercapacitor is a new type of high-efficiency power source with high energy density,which has the advantages of long cycle life and safety.Zeolitic Imidazolate Frameworks(ZIF)belong to a kind of Metal Organic Frameworks(MOF).In the lab,ZIF are used in the electrode materials for supercapacitors due to their controllable morphology and structure as well as abundant redox active sites.However,because of the shortcomings of low specific capacity,poor rate performance and so on,it is limited in the research and application of electrode materials.In order to improve the electrochemical performance of electrode materials,this paper conducts the following researches on the basis of ZIF:(1)Herein,we report the two-step synthesis of bimetallic copper cobalt selenide nano materials embedded in N-doped carbon layers((Cu Co)Se/NC)by using metal-organic framework(MOF)as the functional templates.Benefitting from the Cu incorporation in Co Se matrix and integration of MOF-derived carbon layers,the optimized(Cu Co)Se/NC electrode delivers a reasonably high specific capacity at 1 A/g with outstanding rate capability and cycling stability.After 5000 cycles,the supercapacitor device based on this material capacity barely decayed.Our work provides new opportunities for the rational design and construction of transition-metal selenide based battery-type electrodes for high-performance energy storage devices.(2)In order to improve the electrochemical properties of copper and cobalt bimetallic MOF derived materials,we report the rational design and synthesis of Cu doped CoP nanosheet arrays on carbon cloth,which are derived from the oxidation and phosphorization of metal-organic frameworks(MOF)templates.By introducing suitable amount of Cu species in CoP matrix derived from MOF,the electrical conductivity of the overall electrode with rich porosity can be further enhanced.And the electrode material with the best electrochemical performance Cu:CoP-0.5 was screened by controlling the proportion of copper and cobalt.The Cu:CoP-0.5exhibits excellent specific capacity(113.3 m Ah/g)at a current density of 8 A/g(3.3 times that of CoP)with improved cycle performance.(3)The supercapacitor is assembled based on the Cu:CoP-0.5 electrode,exhibiting the energy density of 31.5 Wh/kg at the power density of 15910.1 W/kg.The present work demonstrates the potentials of Cu:CoP nanosheet arrays for practical applications and provides a new avenue for the development of novel electrodes toward high-performance energy-storage systems.