Preparation,Characterization And Property Of Copper Phosphide/Carbon-based Composites

The copper phosphide?Cu₃P?has a high theoretical capacity due to its unique interstitial structure,which is widely considered by researchers to be a good electrode anode material,but the monomer phosphating copper has its own limitations,the volume is easy to expand,collapse,the conductivity is not high,and the cycle performance is poor,etc.The carbon material has a stable structure,it has the advantages of small volume effect and excellent electrical conductivity during charge and discharge.The nanocomposites formed by the combination of copper phosphide and carbon materials accumulate the advantages of two materials,which can alleviate the volume expansion of the electrode material during charging and discharging,and also improve the ability to store charge.Therefore,the study of composite electrode materials for phosphide and carbon materials is of great significance.In this paper,a series of phosphatingcopper/carbon-basednanocompositeswerepreparedby solvothermal in-situ synthesis.The control variables were used to adjust the morphology and size of the phosphide/carbon-based nanocomposites in the experiment,the electrochemical properties of copper phosphide/carbon-based nanocomposites under different conditions were tested on related instruments,and the mechanism of composites formation were speculated.The main work is as follows:?1?Preparation,characterization and electrochemical properties of copper phosphide/reduced graphene oxide?Cu₃P/rGO?nanocompositesCopper phosphide/reduced graphene oxide?Cu₃P/rGO?nanocomposites were successfully synthesized in the presence of surfactant CTAB With copper sulfate pentahydrate,white phosphorus and graphene oxide?GO?as the main raw materials,ethylene glycol and ammonia water as mixed solvents.The prepared nanocomposites were characterized by X-ray powder diffractometry and field emission scanning electron microscopy.It was found that the spherical nanoparticles were about 70 nm in diameter,and uniformly anchored on the surface of the reduced graphene oxide nanosheets.Through a series of electrochemical test results show that the specific capacitance can reach to1080.2 F g^-11 when the sweep speed is 2 mV s^-1,and the discharge specific capacity is 319.0 F g^-11 when the current density is 2.5 A g^-1,in the supercapacitor.Lithium battery performance test shows that the discharge specific capacity can be respectively stabilized at 626.0 mAh g^-1,494.6 mAh g^-1after 100 constant current charge and discharge tests,at 800 mA g^-1,1.6 A g^-1current density.?2?Preparation,characterization and electrochemical properties of copper phosphate/organic carbon?Cu₃P@C?nanocompositesPhosphating copper/organic carbon?Cu₃P@C?nanocomposites were synthesized in one step by solvothermal method.Through controlling the amount of polyethylene glycol 10000 to control the degree of compounding of the material,the morphology analysis found that when added a proper amount of polyethylene glycol 10000,the prepared copper phosphide/organic carbon?Cu₃P@C?nanocomposite has a large number of spherical copper phosphide nanoparticles are uniformly and firmly embedded in the organic carbon sheet.The electrochemical performance was found that the specific capacitance can reach 960.8 F g^-11 at a sweep speed of 1 mV s^-11 in the cyclic voltammetry test,and the discharge specific capacity can reach 796.7 F g^-11 when the current density is 1.5 A g^-11 in constant current charge and discharge test.After 2800cycles,the cycle efficiency can still reach 90.4%,the composite exhibits high cycle stability.?3?Preparation,characterization and electrochemical properties of copper phosphide/multiwalled carbon nanotubes?Cu₃P/MWCNTs?nanocompositesCopper Phosphating/multi-walled carbon nanotubes?Cu₃P/MWCNTs?were prepared by one-step solvothermal method using copper sulfate pentahydrate,white phosphorus and multi-walled carbon nanotubes?MWCNTs?as raw materials,isopropanol and absolute ethanol as mixed solvents.When an appropriate amount of multi-walled carbon nanotubes is added,the copper phosphide nanoparticles are uniformly intercalated on the surface of the multi-walled carbon nanotubes.The electrochemical performance test results show that the first discharge specific capacity is 1765.0 mAh g^-11 at a current density of 1000 mA g^-1,after 100 constant current charge and discharge,the reversible capacity is 798.0 mAh g^-1,after cycling 100 times at a current density of 1600 mA g^-1,the reversible capacity can still reach 680.0 mAh g^-1.It is indicated that the prepared Cu₃P/MWCNTs nanocomposites have good electrochemical properties.