Modification Of Aluminum Current Collector Via Electric Discharge Technology And The Study And Applications Of The Interface Optimization

In recent decades,the issue of energy has been brought to the forefront because of the dramatic reduction of non-renewable energy sources caused by the massive burning of fossil fuels.In order to improve the existing problems in the energy field,various energy storage devices have been in great development.As a kind of energy storage device with high energy conversion efficiency,supercapacitor shows great application value because of its advantages of high power density,short charging time,long cycle life,safety and environmental protection.In this paper,the current collector,a component of supercapacitor,is studied.The aluminum foil as a normal current collector is modified by using the existing electric discharge technology in industry and it is used to prepare the supercapacitors.In the study of current collector modification part,some physical tests,including X-ray diffraction?XRD?,scanning electron microscope?SEM?,energy dispersive X-ray spectrometer?EDS?,Raman test?Raman?,X-ray photoelectron spectroscopy?XPS?,is used to analyze the modified surface.The study of surface microstructure contributes to electric discharge process.Through the analysis,it is clear that the modification process is only carried out on the surface of aluminum foil,and the overall structure of aluminum foil is not damaged,which guarantees the supporting role of aluminum foil as a current collector.At the same time,the carbon on the graphite rod electrode will be adhered to and embedded in the aluminum foil surface,which is conducive to forming a three-dimensional structure at the interface between the aluminum foil and the electrode material.The modification process is conducive to the combination of electrode material and current collector,forming a good conductive channel and forming a protective layer on the aluminum foil surface to prevent it from being oxidized.After the analysis of the modified aluminum foil,supercapacitors containing two electrodes were prepared by the modified aluminum foil.In order to explore the application value of modified aluminum foil,the supercapacitors were a carbon-based organic supercapacitor.Compared with various electrode materials,carbon-based organic supercapacitors have higher commercial value and wider application range,which has certain reference and application value for the research on current collectors.Through the tests of cyclic voltammograms?CV?,constant current charge and discharge?GCD?,alternating current impedance?EIS?and others,we get known that the modified samples have better electrochemical properties,including the higher utilization of active material(specific capacitance can be learned from the electrode materials:in 5 mV s^-1 voltage scanning rate,the modification sample is136 F g^-1 and before modification is 90 F g^-1),a smaller resistance?modified sample equivalent resistance is 0.3?,the one before modification is 17??,large current charge and discharge performances,etc.In addition,the samples of supercapacitor prepared by modified current collector were further studied,including the tests of extending its voltage window?up to 3.5 V?,the test of large current circulation and the rate capability.In this part of the exploration process,the modified sample illustrates good performances.In this paper,the production line process of 4000 F capacitive supercapacitor was prepared based on the modified current collector.Due to the laminar structure in which multiple ultracapacitors are connected in parallel in the high capacitive supercapacitor,the resistance itself is very small,so the performance advantages brought by the modified current collector and reducing the resistance cannot be clearly reflected in this part.However,the stability and the performances of the samples prepared by the modified current collector can meet the requirements of the supercapacitor and have the application value to the extent.In conclusion,the current collector modification can effectively improve the performances of carbon-based organic supercapacitors and have some reference value.