Lithium metal batteries(LMBs)of an ultrahigh theoretical energy density have attracted lots of attentions for a wide range of practical applications.However,there are still numerous challenges in LMBs system,such as p...Lithium metal batteries(LMBs)of an ultrahigh theoretical energy density have attracted lots of attentions for a wide range of practical applications.However,there are still numerous challenges in LMBs system,such as poor cycling performance,complicated interfacial reactions,low Coulombic efficiency,and uncontrollable lithium dendrites.Understanding Li^+ions’nucleation mechanism is essential to tackle the uncontrolled growth of lithium dendrites.However,the nucleation behavior of Li+ions is interfered by the structural complexities of existing substrates during the reduplicative plating/stripping process and the rational mechanism of uniform nucleation of Li^+ions has not been clearly understood from the theoretical point of view.In our work,first-principles theoretical calculations are carried out to investigate the Li^+ions nucleation performance on metal-doped Cu surfaces(MDCSs)and the key descriptors that determines the properties of various MDCSs are systematically summarized.It is found that the introduction of heterogeneous doping Ag and Zn atoms will induce a gradient adsorption energy on MDCSs,and such gradient deposition sites can reduce the diffusion barriers and accelerate the diffusion rates of Li+ions dynamically.By maneuvering the Li+ions nucleation on MDCSs,a dendrite-free lithium metal anode can be achieved without the use of porous matrixes and complex synthesis process,which can be attributed to suppress the uncontrollable lithium dendrites for realizing the high-efficiency LMBs.展开更多
Anion ion photoelectron spectroscopy and density functional theory （DFT） are used to investigate the electronic and structural properties of ScSin （n = 2 - 6） clusters and their neutrals. We find that the structur...Anion ion photoelectron spectroscopy and density functional theory （DFT） are used to investigate the electronic and structural properties of ScSin （n = 2 - 6） clusters and their neutrals. We find that the structures of ScSin^- are similar to those of Sin＋1^-. The most stable isomers of ScSin^- cluster anions and their neutrals are similar for n=-2, 3 and 5 but different for n=4 and 6, indicating that the charge effect on geometry is size dependent for small scandiumsilicon clusters. The low electron binding energy （EBE） tails observed in the spectra of ScSi4,6^- can be explained by the existence of less stable isomers. A comparison between ScSin and VSin clusters shows the effects of metal size and electron configuration on cluster geometries.展开更多
Single crystals of 4SC（NH2）2–Ni1-xCux Cl2（x = 0.03）（Cu-DTN） containing spin S = 1/2 Cu^2＋and S = 1 Ni^2＋cations are synthesized by slow evaporation methods. Structural characterization demonstrates that the C...Single crystals of 4SC（NH2）2–Ni1-xCux Cl2（x = 0.03）（Cu-DTN） containing spin S = 1/2 Cu^2＋and S = 1 Ni^2＋cations are synthesized by slow evaporation methods. Structural characterization demonstrates that the Cu-DTN is of a tetrahedral structure with lattice parameter c being 9.0995 A, which is 1.32% expansion compared with that of parent material DTN due to the larger radius of the Cu ion. Direct current（DC） susceptibility measurements show that both the antiferromagnetic exchange interaction at low temperature and the large anisotropy of susceptibilities are suppressed after doping the Cu ion, which could be related to the structural distortion and the increase of the super-exchange paths in Cu-DTN.展开更多
The direct band gap ZnTe with transition metal （TM） impurities plays a vital role in optoelectronic and spintronic applications. In the present study, we use the advanced modified Becke-Johnson （mBJ） functional fo...The direct band gap ZnTe with transition metal （TM） impurities plays a vital role in optoelectronic and spintronic applications. In the present study, we use the advanced modified Becke-Johnson （mBJ） functional for performing the structural computations and detailed investigations of the optical characters in Zn1_xTMxTe （TM = Fe, Co） alloys with 0 ≤ x ≤1. By employing the FP-LAPW method, we determine various optical parameters for the ternary alloys and for the end binaries. The calculated static dielectric constants and optical band gaps for Zn1_xTMxTe （TM = Fe, Co） have an inverse relation that verifies the Penn model. We find that the static dielectric constant is nearly equal to the square of the static refractive index, and both increase with TM content. Furthermore, we also find a slight shift of peaks to a higher energy region with increasing TM concentration. The decreasing band gap and high value of the absorption in the visible region of electromagnetic spectrum make these alloys suitable for photonic and solar cell applications.展开更多
基金supported by the National Key Research and Development Program of China(No.2017YFB0702100)the National Natural Science Foundation of China(11404017)+2 种基金the Technology Foundation for Selected Overseas Chinese Scholar,Ministry of Human Resources and Social Security of Chinasupport by the European Regional Development Fund in the IT4Innovations national supercomputing center-Path to Exascale project,No.CZ.02.1.01/0.0/0.0/16_013/0001791 within the Operational Programme Research,Development and Educationby the Ministry of Education by the Ministry of Education,Youth,and Sport of the Czech Republic and grant No.17-27790S of the Czech Science Foundations
文摘Lithium metal batteries(LMBs)of an ultrahigh theoretical energy density have attracted lots of attentions for a wide range of practical applications.However,there are still numerous challenges in LMBs system,such as poor cycling performance,complicated interfacial reactions,low Coulombic efficiency,and uncontrollable lithium dendrites.Understanding Li^+ions’nucleation mechanism is essential to tackle the uncontrolled growth of lithium dendrites.However,the nucleation behavior of Li+ions is interfered by the structural complexities of existing substrates during the reduplicative plating/stripping process and the rational mechanism of uniform nucleation of Li^+ions has not been clearly understood from the theoretical point of view.In our work,first-principles theoretical calculations are carried out to investigate the Li^+ions nucleation performance on metal-doped Cu surfaces(MDCSs)and the key descriptors that determines the properties of various MDCSs are systematically summarized.It is found that the introduction of heterogeneous doping Ag and Zn atoms will induce a gradient adsorption energy on MDCSs,and such gradient deposition sites can reduce the diffusion barriers and accelerate the diffusion rates of Li+ions dynamically.By maneuvering the Li+ions nucleation on MDCSs,a dendrite-free lithium metal anode can be achieved without the use of porous matrixes and complex synthesis process,which can be attributed to suppress the uncontrollable lithium dendrites for realizing the high-efficiency LMBs.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KJCX2-EW-01)the National Natural Science Foundation of China (Grant Nos. 20853001 and 10874007)
文摘Anion ion photoelectron spectroscopy and density functional theory （DFT） are used to investigate the electronic and structural properties of ScSin （n = 2 - 6） clusters and their neutrals. We find that the structures of ScSin^- are similar to those of Sin＋1^-. The most stable isomers of ScSin^- cluster anions and their neutrals are similar for n=-2, 3 and 5 but different for n=4 and 6, indicating that the charge effect on geometry is size dependent for small scandiumsilicon clusters. The low electron binding energy （EBE） tails observed in the spectra of ScSi4,6^- can be explained by the existence of less stable isomers. A comparison between ScSin and VSin clusters shows the effects of metal size and electron configuration on cluster geometries.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11404316 and 11304159)the Natural Science Foundation of Jiangsu Province+2 种基金Chinathe Science Foundation of Nanjing University of Posts and TelecommunicationsChina(Grant Nos.BK20140863 and NY213075)
文摘Single crystals of 4SC（NH2）2–Ni1-xCux Cl2（x = 0.03）（Cu-DTN） containing spin S = 1/2 Cu^2＋and S = 1 Ni^2＋cations are synthesized by slow evaporation methods. Structural characterization demonstrates that the Cu-DTN is of a tetrahedral structure with lattice parameter c being 9.0995 A, which is 1.32% expansion compared with that of parent material DTN due to the larger radius of the Cu ion. Direct current（DC） susceptibility measurements show that both the antiferromagnetic exchange interaction at low temperature and the large anisotropy of susceptibilities are suppressed after doping the Cu ion, which could be related to the structural distortion and the increase of the super-exchange paths in Cu-DTN.
基金supported by the Deanship of Scientific Research at King Saud University(for Shahid M Ramay)(Grant No.RG 1435-004)the University of the Punjab,Lahore for financial support through Faculty Research Grant Program(for M Hassan)the HEC Pakistan(Grant No.21-261/SRGP/R&D/HEC/2014)(for M Yaseen)
文摘The direct band gap ZnTe with transition metal （TM） impurities plays a vital role in optoelectronic and spintronic applications. In the present study, we use the advanced modified Becke-Johnson （mBJ） functional for performing the structural computations and detailed investigations of the optical characters in Zn1_xTMxTe （TM = Fe, Co） alloys with 0 ≤ x ≤1. By employing the FP-LAPW method, we determine various optical parameters for the ternary alloys and for the end binaries. The calculated static dielectric constants and optical band gaps for Zn1_xTMxTe （TM = Fe, Co） have an inverse relation that verifies the Penn model. We find that the static dielectric constant is nearly equal to the square of the static refractive index, and both increase with TM content. Furthermore, we also find a slight shift of peaks to a higher energy region with increasing TM concentration. The decreasing band gap and high value of the absorption in the visible region of electromagnetic spectrum make these alloys suitable for photonic and solar cell applications.
