Study On Properties Of Graphene Composites Based On Energy Storag

With the rapid development of society in the new era,the reserves of traditional fossil fuels are decreasing.People began to look for green,renewable new energy,but also vigorously develop energy storage devices.Because of its high efficiency,convenience and environmental friendliness,the super-capacitor,whose core component is electrode material,have shine in many fields in recent years.In this thesis,graphene/metal oxide composite electrode materials were prepared from metal oxide and graphene oxide by hydrothermal synthesis.The experiment condition and types of metal oxide were determined by orthogonal experiment design.After analyzing and comparing the phase structure and electrochemical performance of the composites,the electrochemical data were fitted by Origin software.The experimental evaluation indices are specific capacitance of the electrodes and the slope of low frequency line in Nyquist diagram.Through comparative analysis of the best data of the two experimental indices,the optimum synthesized conditions of graphene composites were selected as follows:Metal oxide MnO2,metal oxide:graphene oxide=1:1,hydrothermal temperature 160℃,hydrothermal time 10h.This study provides a reference path for the preparation of graphene/metal oxide composite electrode materials by hydrothermal method.Under the optimal preparation conditions,graphene was prepared by hydrothermal method,and then MnO2 was formed on the surface of graphene by chemical coprecipitation method to prepare graphene/MnO2 composite electrode materials,and graphene electrode materials were used as reference.The morphology,phase structure and electrochemical performance of the two materials were characterized and analyzed,and the results showed that performance of graphene/MnO2 composite electrode is excellent and maintains a high electrochemical level.Under the ampere density of 0.2A·g-1,the specific capacitance is as high as 105.5F·g-1.When the current density rises to 1A·g-1,the capacitance retention of the electrodes remains as high as 90.2%.This shows that graphene/MnO2 composite electrodes are a more excellent material for energy storage.