| In the past two years,zinc/iodine energy storage devices have emerged and become the research hotspots of many research institutions.The research on zinc/iodine storage electrodes has been carried out in large scale.As the hottest material in the past decade,graphene has been widely used in energy storage,solar cells,field emission and sensors.Especially in the field of energy storage,graphene has become a popular research material.In this paper,a three-dimensional porous structural material graphite felt（GF）with low cost,corrosion resistance and good electrical conductivity is used as the zinc/iodine storage electrode material.Because of its large void structure,the internal carbon fiber is complex and can provide a large specific surface area,which can be used as a good energy storage electrode material.The effective combination of graphene and graphite felt will have a good research and development prospect in the field of energy storage.Firstly,the hydrophilicity and electrochemical activity of the graphite felt are not very good.The original graphite felt was pretreated by acid treatment and heat treatment,respectively.Acid treatment is that the graphite felt is acid-treated by RCA（Industry Standard Cleaning Process）,and the surface of the graphite felt was etched to have some gullies on the surface,so that the specific surface area is increased.At the scan rate of 10mV/s,the specific capacitance of the electrode material increased by 11%.The heat treatment is carried out by using a rapid thermal annealing furnace and heating at 800℃,900℃,and 1000℃for 30s,1min,and 2min in a vacuum atmosphere,so that the surface of the graphite felt is uneven,thereby increasing the surface area.At 800℃,2min heat treatment,the graphite felt can obtain a maximum specific capacitance of 2F/cm2,and compared to the original graphite felt,it has a longer charge and discharge time at the current density of 5mA/cm2.Secondly,we prepared graphene oxide（GO）by Hummers,and the reduced graphene oxide（RGO）was prepared by reducing graphene oxide with ethanol under high temperature and pressure,and then it was grown on the surface of graphite felt to form the electrode material reduced graphene oxide-graphite felt（RGO-GF）.The concentration ratio of different graphene oxide to ethanol was investigated,and the electrochemical performance of the electrode material RGO-GF in zinc iodide solution was investigated.The results show that the graphite felt grown with the reduced graphene oxide has superior specific capacity,charge and discharge time,and electrical conductivity as compared with the original graphite felt.According to the morphology and structure characterization and electrochemical performance test,when the concentration ratio of graphene oxide（GO）to ethanol reaches 5.3%,the best quality RGO is grown on the graphite felt.At a scan of 10mV/s,the specific capacity reached 2.1 F/cm2,and at the current density of 5 mA/cm2,the charge and discharge time was doubled,and the resistance was the smallest.Therefore,RGO-GF electrode materials have a good development and application prospect in the field of zinc/iodide energy storage.In addition,a large number of researchers now focus on the research field of zinc/iodine storage electrodes,and the high performance of zinc/iodine storage can also be achieved by inhibiting the growth of zinc dendrites and reducing the precipitation of ZnI3?5H2O.In this paper,ethanol is used as a representative of alcohols to study the effect of alcohol electrolyte additives on the energy storage performance of zinc/iodine.The results show that ethanol can be used as an electrolyte additive to effectively reduce the growth of zinc dendrites after long-term voltammetry cycle,and the organic cations produced by ethanol can be combined with zinc ions to reduce the precipitation.Electrochemical analysis was performed by cyclic voltammetry（CV）,elctrochemical impedance spectroscope（EIS）,and Galvanostatic charge-discharge（GCD）.Finally,when the concentration ratio of ethanol to 0.1M zinc iodide solution is 10%,the complexation of ethanol and zinc ions occurs most thoroughly,with the largest specific capacity of 1.99F/cm2 and the smallest solution resistance of 7.20Ω,the longest Charge and discharge time. |
