| With the development of science,technology,and industry,the energy demand is increasing.As the depletion of traditional energy sources and the deterioration of the ecological environment,people have realized the importance of developing sustainable and clean energy.Therefore,exploring new energy materials with high performance,low pollution,and low cost has become a popular research topic in recent years.Low-dimensional nanomaterials exhibit novel and excellent performance in electrical,optical,magnetic,and thennodynamic areas due to their unique size,surface,and quantum confinement effects.The electronic structure and properties of low-dimensional materials could be regulated by metal atom adsorption or hetero atom doping,which make them useful in the fields of nano electronics,catalysis and energy storage.In this paper,by using first-principles calculations we studied the behaviors of metal atoms adsorbed on low-dimensional materials and the application of low-dimensional materials in lithium-ion batteries.Firstly,we studied the electromagnetic properties of BC3 and AIC3 caused by metal atom adsorption,and predicted the potential application of some metal adsorption systems in the fields of rechargeable batteries,hydrogen storage,catalysis,and spin electronic device.Then,in order to make a contribution to alleviating the energy crisis,we have further studies on the field of rechargeable batteries.We proved the effect of hetero atom doping on anode materials from the perspective of electronics.The main contents are as follows:1.By using first-principles calculation,we studied the adsorption properties of some alkali metal atoms,alkaline earth metal atoms.IIIA metal atoms and transition metal atoms on two-dimensional BC3 and AIC3.By analyzing the density of states,we find that the main contribution orbit of substrates during bonding process is the p-orbital of carbon atoms.The role of doping atoms is to enhance the ability of surrounding carbon atoms to interact with electron donors.By calculating and analyzing the band structure,density of states and magnetic properties,we predicted the possible application of metal atom adsorption system of BC3 and AIC3 in the fields of rechargeable batteries,high temperature superconductivity,hydrogen storage,single atom catalysis and spintronics.2.Based on the research of BC3,we further studied the theoretical feasibility of one-dimensional boron-doped graphene nanobelts(BGNR)as anode materials for lithium-ion batteries.By using first-principles calculation,we studied the adsorption performance,diffusion behavior and storage capacity of Li on BGNR.The most favorable adsorption site in BGNR is the hollow site of B para-doping,with adsorption energy of-1.55 eV.By calculating the partial density of states of Li on BGNR,we find that the main contribution orbit involved in charge transfer in BGNR is the p-orbital of C atoms.Doping of B atoms can effectively promote the charge transfer between C atoms and Li atoms.By using transition state search,we find that Li tend to migrate along the growth direction of BGNR,and 7 carbon atom widths BGNR can provide a certain direction for Li diffusion.Finally,we calculated the capacity of BGNR and GNR.The capacity is 783mAh/g for BGNR and 52mAh/g for GNR.Doping of B atoms can increase the capacity of GNR by nearly 15 times.Our research shows that B atoms doped in GNR can effectively enhance the adsorption of Li atoms and greatly increase the capacity,our research provides useful theoretical guidance for the application of BGNR in anode materials of lithium ion batteries.3.After studied the graphene-based anode material,we conducted a theoretical study on the feasibility of phosphorus-doped molybdenum disulfide(P-MoS2)as an anode material for lithium ion batteries.P-MoS2 is another kind of popular anode materials(transition metal disulfide).Based on first-principles calculations,we calculated the adsorption performance,migration behavior and storage capacity of Li on P-MoS2.It has been found that the doping of P atom makes the surrounding environment becoming electron-deficient state,which is beneficial to the adsorption of Li.MoS2 is a direct band gap semiconductor,P atom doping makes the system metallic.By analyzing the adsorption properties of Li atoms,we found that doping of P atom significantly improved the Li adsorption ability of the substrate,the closer to the P atom,the stronger adsorption ability is.By using transition state search,we found that doping of P atom in MoS2 has little influence on the diffusion barrier.The Li atoms can rapidly diffuse on both sides of P-MoS2 in a zigzag diffusion path.The theoretical storage capacity of P-MoS2 is relatively small,which would limit its usage as anode electrode material for lithium ion batteries.However,the superior adsorption and migration ability of Li atom on P-MoS2 will provide useful reference for the research of P-MoS2 in other fields. |
