Electrochemical Performance Study Of Modification Graphene By Electron Beam Irradistion

With the economic development, there is environment-friendly energy, and ecological environment has become increasingly concerned about a new type of advanced Li-ion batteries(LIBs) and super-capacitors has gained more and more attention. Graphene, a new two-dimensional nanomaterials, has attracted huge attention due to its outstanding physical, chemical and mechanical properties, such as large theoretical specific surface area and high electrical conductivity. In this paper, high energy pulse electron beam was used as the main means to modified graphene, such as reduction, precious metals or nitrogen doping modification. Also the electrochemical properties of the modified material were studied. The main contents are as follows:1. In terms of reduction graphene modification materials, Graphene oxide was prepared from nature graphite via a way of modified Hummer’s method, and then, reduced to graphene nanosheets by high energy pulse electron beam(EB) irradiation. The structures were characterized and the electrochemical properties were studied. The study found that the electron beam irradiation dose not only can lead to graphene with different reduction degree, also can lead to them had different structure and surface defects. The electrochemical performance results found that When the irradiation dose was 350 KGy, the modified graphene sheets demonstrated very high lithium storage capacity and good cycle stability, the reversible capacity can reach 1024.5 m Ah/g, and the reversible capacity is in the range of 1024~831 m Ah/g with a capacity retention of 81% after 20 cycles.2. In terms of doping precious metals graphene modification materials, EB irradiation method for both the reduction of graphene oxide and loading of Ag nanoparticles(Ag NPs) were achieved. Further, the effects of irradiation dose on the morphology of Ag NPs and the sheet resistance of Ag nanoparticles/reduced graphene oxide(Ag NPs/r GO) were studied. The results reveal that the size of the Ag NPs decreased and became uniformly distributed over the surface of the r GO nanosheets. The sheet resistance of the Ag NPs/r GO films decreased with decreasing Ag NPs size. The lowest sheet resistivity of 0.06 Ω?m was obtained in the film corresponding to 350 k Gy irradiation dose. The formation mechanisms, structure characteristics and performance of the as-prepared Ag NPs/r GO nanocomposites were proposed.3. In terms of doping nitrogen graphene modification materials, EB irradiation simultaneous reduction GO and N-doping, successfully synthesized nitrogen/reduced graphene oxide(N/r GO). Mainly studied the different irradiation dose on the influence of the structure and electrical properties of N/r GO. The results reveal that the lowest sheet resistivity of 0.024 Ω?m was obtained in the film corresponding with 350 KGy of irradiation dose. It also showed the highest capacitance(97.08 F g-1) and cycle performance.