The Synthesis And Electrochemical Performance Of Mo-Doped CuO Nanostructure

Supercapacitors（SCs）with fast charge/discharge rate,high power density and long cycle-life cause widespread concern for energy-storage devices.Electrode material is an important part of supercapacitors,which determines the performance of supercapacitors.Transition metal oxide is an important potential electrode material,which has attracted attention due to its remarkable specific capacitance and energy density.Among multifarious transition metal oxides,Copper oxide（CuO）has received extensive attention due to its high theoretical specific capacitance(1800 F g^-1),low cost,natural abundance,environment friendly and simple preparation.However,its relatively low intrinsic conductivity has limited its development.Herein,this paper focuses on improving and optimizing Mo-doped CuO electrode materials,Mo-CuO and Mo-CuO-2/Co（OH）₂ composite nanostructures are synthesized.We investigated the effects of different doping concentrations of Mo on electrical conductivity,and electrochemical performance.Then Mo-CuO-2 as cathode and the activated carbon（AC）as anode are assembled into an asymmetric SC cell（ASC）.The main research contents are as follows:（1）Pure Cu O and Mo-doped CuO nanostructure on Ni foams were obtained by combining a simple hydrothermal process and calcination treatment.We investigated the effects of different doping concentrations of Mo on morphology,electrical conductivity,and electrochemical performance.The study found that the Mo-CuO-2Mo doping concentration has a maximum value for the conductivity of the synthesized Mo-CuO nanostructures,and also shows the highest specific capacitance.Its specific capacitance can reach 1392 F g^-1 at a current density of 2 A g^-1;after10,000 cycles,the initial capacitance retention rate is 76%.In addition,Mo-CuO-2 as cathode and the activated carbon（AC）as anode are assembled into an asymmetric SC cell（ASC）.The Mo-CuO-2//AC ASC exhibits a superhigh energy density of 36 Wh kg-¹ at a power density of 810 W kg-¹.（2）We rationally designed and prepared Co（OH）₂,Mo-CuO-2/Co（OH）₂ on Ni foams by electrodeposition.The interconnected Co（OH）₂ nanosheets grow almost vertically on the surface of Mo-CuO-2.The open structure can provide channels for ion conduction and electrolyte diffusion,which is beneficial for the electrolyte to enter the internal material.Mo-CuO-2/Co（OH）₂ exhibits extremely high specific capacitance of1617 F g^-1 at 2 A g^-1,and it also maintains the initial capacitance retention of approximate 80%after 5000 cycles.It shows that the reasonable nanostructure design makes the composite materials effectively play a synergistic effect and can obtain good electrochemical performance.