Construction Of Micro-nanostructure CuO/rGO Lithium Ion Battery Anode Materials And The Research Of Electrochemical Performance

Lithium-ion batteries have the characteristics of high energy density and long cycle life.It is widely used in the portable electronics market and shows a broader prospect in the field of power batteries in the future.However,the theoretical capacity of commercial anode material graphite is low,which limits the application of lithium-ion batteries in devices with higher energy density requirements.In recent years,the transition group metal oxide is a conversion-type reaction mechanism,which has the advantage of high capacity,and has attracted attention in the development of anode materials.CuO,which is rich in resources,have a high theoretical specific capacity,and is environmentally friendly,which shows its great potential as a negative electrode material.It is a pity that during the long-term cycle charge and discharge,CuO will have the characteristics of volume change,and the phenomenon of electrode material breakage will occur,resulting in the problem of rapid decrease of copper oxide capacity.As a solution,researchers have developed micro-nano-sized CuO with the purpose of overcoming stress relaxation during lithium extraction.As another solution,we tried to add a carbon-based coating material such as graphene to CuO,so that the purpose is to alleviate the volume change of CuO during charging and discharging,and increase the contact area between the active material and the electrolyte.Due to the mutual attraction of van der Waals forces between graphene layers,it will tend to reunite or reorganize into graphite sheets,which requires us to process graphene to increase the wettability and dispersibility of graphene.The content of this paper includes the process of regulating the growth of micro-nano structure CuO,formulating graphene dispersion,and preparing CuO/rGO composite materials.Three different methods for preparing CuO/rGO composite materials were designed and explored longitudinally.The electrochemical properties were compared and analyzed laterally,including between CuO and CuO/rGO composite materials,between different morphology CuO/rGO composite materials,and between different ratios of composite materials.This article analyzes the influence of the structure of the composite material on the electrochemical performance of the material through different characterization methods.This experiment discusses the influence of different preparation processes of composite materials on the structure and morphology of materials,and realizes the controllable preparation process of composite materials with special morphologies.The conclusion of the actual study is as follows:?1?In this paper,the solid-phase method was used to prepare CuO/rGO composites with blade-like and spherical-like shapes.High temperature causes the precursor to calcinate and decompose.In this experiment,the difference in morphology of CuO was related to the anion hydrolyzed by the precipitant.The precursors were Cu₄?OH?₆SO₄and Cu₂?OH?₂CO₃.The actual calcination temperature was 450?.Comparing the Cyclic voltammetry characteristic curves between different CuO and CuO/rGO composite materials,the actual material charging and discharging process is similar,they are all CuO conversion cycle mechanism.During the charge-discharge cycle,compared with the electrode materials CuO and CuO/rGO with different morphologies,the spherical composite materials have better stability than CuO materials.The material was cycled 100 times at the current density of 0.2Ag^-1,and the specific capacity was186mAhg^-1.?2?This chapter analyzes the changes in the composition of the solution and the process of grain growth,by studying the hydrothermal reaction of the solution method.In the experiment,the copper source with a concentration of 0.05mol/L can be obtained to obtain a good morphology of CuO,which was reacted at 160?for 16 hours.Considering the excellent electrochemical performance of the composite materials,the composite materials with four different morphologies are compared.The spherical-like CuO/rGO electrode material with a diameter of 3?m has high-capacity stability.After100 cycles at a current density of 0.2Ag^-1,its capacity remains at 295 mAhg^-1.At a high magnification of 3Ag^-1,its capacity is 194 mAhg^-1.?3?This experiment adopts the one-pot experimental method,which does not separate the intermediate substance,and the same time directly obtains the CuO/rGO composite material.This article discusses the relationship of the interface of the composite material,in which the intermediate product of organic copper appears during the synthesis process.This chapter compares the electrochemical performance of composite materials with different ratios,and designs a higher capacity CuO/rGO composite material.The data shows that the capacity of T100 reaches 504mAhg^-1,and the specific capacity of the material is still 246.3mAhg^-1 at a current density of 3Ag^-1.