Preparation And Electrochemical Properties Of Mxene/carbon Fiber Composites Based On Electrospinning

Supercapacitors have excellent performance in power density and cycle life,which makes them have great development prospects in the field of high power and stability requirements.The electrochemical performance of supercapacitors is influenced by electrode materials,electrolyte and membrane,and the electrochemical performance of the capacitor is determined by the performance of electrode materials.Two-dimensional titanium carbide(Ti₃C₂T_x)is a new type of two-dimensional layered material,have a lot of surface active sites,as well as excellent electric conductivity,is a very promising super capacitor electrode materials,Ti₃C₂T_x/porous carbon fiber(PCNF)electrode is prepared by electrospinning technology,which is composed of Ti₃C₂T_xnanosheet polystyrene microspheres and polyacrylonitrile(PAN).Using electrostatic spinning method,anchor layer less Ti₃C₂T_xnanometer chips in carbon fiber,so as to avoid the Ti₃C₂T_xnano flake stack reunion phenomenon in charge and discharge process,and compared with carbon fiber,porous carbon fiber offers a higher specific surface area,therefore,Ti₃C₂T_x/porous carbon fiber as electrode materials have excellent electrochemical performance.The main research contents of this work are as follows:(1)The small-size two-dimensional titanium carbide nanosheets obtained after treatment were embedded into the porous carbon fibers by electrospinning technology,and the influence of different Ti₃C₂T_xloading loads on the electrochemical properties of the prepared Ti₃C₂T_x/PCNF electrode materials was studied.The Ti₃C₂T_x/PCNF was tested by cross-current charge-discharge.Under the condition of low porosity,the maximum mass specific capacity of the composite electrode was 191.20F/g at the current density of 1A/g.The electrochemical impedance test was carried out on the electrode material.(2)In order to further obtain Ti₃C₂T_x/PCNF electrode materials with better electrochemical performance,we used polystyrene as pore-forming agent to further study the effects of porosity and carbonization temperature on the structure and electrochemical performance of the materials.In 3mol/L KOH electrolyte,0?+0.6V voltage window,1A/g current density,the composite electrode with the largest void fraction obtained the highest mass specific capacity of 292F/g,and still obtained the specific capacity of 169F/g at 10A/g current density.The same Ti₃C₂T_x/PCNF electrode material also shows higher mass specific capacity and electrochemical impedance characteristics than other carbonization temperatures at 600?.In order to explore the influence of different pore-forming materials on the electrochemical performance of the composite electrode,we introduced ZIF-8 as the pore-forming agent and explored the electrochemical performance of the composite electrode material.Under the conditions of 3mol/L KOH electrolyte,0?+0.6V voltage window and 1A/g current density,the maximum specific capacity of the composite electrode reaches 212.33F/g,which is significantly improved compared with 125F/g without ZIF-8.