First-Principles Study On The Migration Of Alkali Ions On Blue Phosphorene And Graphene Intralayer Heterostructures

Nowadays,alkali metal ion batteries,as an indispensable energy storage device in people’s production and life,have been widely used in medical,various electronic equipment,aerospace and other fields.Among them,lithium-ion batteries have been widely used because of their excellent stability,rapid charging and discharging ability and low environmental pollution.However,with the continuous development of human society,people put forward higher and higher requirements for the comprehensive performance of lithium-ion batteries.And the limited lithium resources can’t meet the increasing demand for energy storage.Therefore,we need to develop some highperformance anode materials to improve the comprehensive performance of lithium-ion batteries,and use relatively rich resources of sodium and potassium elements to develop sodium and potassium ion batteries to replace lithium-ion batteries.Compared with traditional experimental research,the first-principies-based computational simulation has been paid more and more attention because of its advantages of convenience,efficiency and feasibility verification from the theoretical level.In this thesis,the performance characteristics of blue phosphorene(hereafter referred to as BlueP)and graphene(hereafter referred to as G)intralayer heterostructures as anode materials for alkali metal ion batteries were studied by first principles calculation,which mainly included the following two parts:1.Theoretical study of blue phosphorene and graphene intralayer heterostructures as anode materials for lithium-ion batteries.Based on density functional theory,the geometric structure and electronic properties of blue phosphorene and graphene intralayer heterostructures with two different interfaces and their adsorption and diffusion properties as negative electrodes of lithium ion batteries were systematically studied.The calculation results show that the blue phosphorene and graphene intralayer heterostructures with two different interfaces have good structural stability,and the blue phosphorene and graphene intralayer heterostructures with zigzag interface have a smaller band gap,which will be beneficial to improve the conductivity of the electrode.In addition,compared with the pristine blue phosphorene monolayer,graphene monolayer and blue phosphorene / graphene interlayer heterojunctions,the adsorption properties of lithium atoms in the blue phosphorene and graphene intralayer heterostructures with the two different interfaces is improved,and the diffusion barrier is reduced.Therefore,these properties indicate that both intralayer heterostructures with different interfaces can be used as potential anode materials for Li-ion batteries.2.Theoretical study on the zigzag interface of blue phosphorene and graphene intralayer heterostructures as anode materials for sodium and potassium ion batteries.The adsorption and diffusion properties of sodium and potassium atoms in the intralayer heterostructure were discussed by first principles calculation.The calculation results show that although the adsorption energy of sodium and potassium atoms on the blue phosphorene and graphene intralayer heterostructure with the zigzag interface is slightly higher than that of lithium atoms in the intralayer heterostructure,its adsorption energy is significantly decreased compared to blue phosphorene and graphene.In addition,although the diffusion barrier of sodium and potassium atoms on the blue phosphorene and graphene intralayer heterostructure with the zigzag interface is higher than that of pristine graphene and blue phosphorene,it is comparable to that of lithium atoms on the intralayer heterostructure.Therefore,the blue phosphorene and graphene intralayer heterostructure with the zigzag interface is promising as a potential anode material for sodium-ion and potassium-ion batteries.