Formation Mechanism Of Automatically Shedded Thin Copper Foils And Graphene/Copper Foils Prepared By Electroless Deposition And Their Application

Copper(Cu)foil is the basic material of electronic and energy industry.Because of its excellent electronic conductivity,high thermal conductivity,high temperature resistance and ideal adhesion performance,Cu foil is widely used in integrated circuits,electronic components,energy storage equipment and aerospace equipment.On the other hand,graphene(Gr)has become an ideal strengthening phase for ultrathin composite Cu foil due to its excellent strength and conductivity.However,it is difficult to prepare copper foil and Gr/Cu composite foil with ultrathin properties and good properties by the existing preparation process.In view of the existing problems in the preparation of ultrathin Cu foil and Gr/Cu composite foil,in this work,self-stripping ultrathin Cu foil and ultrathin Gr/Cu composite foil were prepared by electroless deposition process using modified chitosan as the intermediate layer.The main research contents are as follows:1.Ultrathin Cu foil(ELD Cu foil)with controllable thickness and automatic stripping was prepared by electroless deposition.The thinnest thickness of ELD Cu foil is 746 nm.Without any additional heat treatment,the resistivity of ELD Cu foil is about2.11??·cm.ELD Cu foil has a tensile strength of 285.2 MPa and a hardness of 0.42GPa.The 180°bending test of ELD Cu foil and the measurement of its resistivity after bending show that ELD Cu foil can withstand 99 times of 180°bending and the resistance increases only 0.9%after bending,while commercial electro deposition Cu foil can only withstand 17 times of 180°bending and the resistance increases 4.1%after bending.2.The performance of ELD Cu foil as current collector of lithium-ion battery was studied.The interface strength between ELD Cu foil and anode material of lithium-ion battery is excellent.The battery with ELD Cu foil current collector has better cycle performance and rate performance than commercial Cu foil current collector.In addition,the area density of 746 nm ELD Cu foil is only 0.65 mg cm^-2.The mass specific capacity and energy density of the battery can be increased by 429.6%and484.1%respectively by using ELD Cu foil as current collector.3.Ultrathin nickel-coated graphene(NCG)/Cu composite foils with controllable thickness and automatic stripping were prepared by electroless deposition.When the amount of modified graphene is 30 mg/L,the NCG/Cu composite foil has the best performance.The composite foil has a thickness of 1.1?m,a tensile strength of 338.7MPa and a thermal conductivity of 431.2 W/m K.Compared with pure Cu foil,the bending times and elastic modulus of composite foil are increased by 298.1%and 737.3%respectively.In addition,NCG/Cu composite foil has better heat dissipation performance than Cu foil,so it is an ideal heat management material.