Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, sha...Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, shape, and ionic conductivity of these samples. The results show that the range of solid solution formation is in 0< x ≤0 09, in which the conductivity of these samples raises with the increasing amount of RE 2O 3 (RE=Pr, Nd, Sm, Gd) added, and the diameter of the powders is about 100 nm. Compared with the conventional solid state reaction, the sol gel method needs low temperature and presents high ionic conductivity.展开更多
As an ion conductor, the Al-doped Li1+xAlxGe2-x(PO4)3(LAGP) demonstrates the superionic Li diffusion behavior, however,without the convinced verifications. In this context, the density functional theory(DFT) calculati...As an ion conductor, the Al-doped Li1+xAlxGe2-x(PO4)3(LAGP) demonstrates the superionic Li diffusion behavior, however,without the convinced verifications. In this context, the density functional theory(DFT) calculations are employed to clarify the structural origin of the fast Li ion migration kinetics in LAGP solid electrolytes. The calculated results show that doping of Al leads to an emerging high-energy 36 f Li site, which plays an important role in promoting the Li diffusion and can largely lower the Li ion diffusion energy barrier. Moreover, the Li/Al antisite defect is investigated firstly, with which the Li ions are excited to occupy a relatively high energy site in LAGP. The obvious local structural distortion by Li/Al antisite results in the coordination change upon Li diffusion(lattice field distortion), which facilitates the Li diffusion significantly and is probably the main reason to account for the superionic diffusion phenomenon. Therefore, the occupation of Li at high-energy sites should be an effective method to establish the fast Li diffusion, which implies a rewarding avenue to build better Li-ion batteries.展开更多
文摘Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, shape, and ionic conductivity of these samples. The results show that the range of solid solution formation is in 0< x ≤0 09, in which the conductivity of these samples raises with the increasing amount of RE 2O 3 (RE=Pr, Nd, Sm, Gd) added, and the diameter of the powders is about 100 nm. Compared with the conventional solid state reaction, the sol gel method needs low temperature and presents high ionic conductivity.
基金supported by the National Key Research and Development Program of China (Grant No. 2019YFA0705700)National Natural Science Foundation of China (Grant No. 11704019)+1 种基金the Hundreds of Talents Program of Sun Yat-sen Universitythe Fundamental Research Funds for the Central Universities。
文摘As an ion conductor, the Al-doped Li1+xAlxGe2-x(PO4)3(LAGP) demonstrates the superionic Li diffusion behavior, however,without the convinced verifications. In this context, the density functional theory(DFT) calculations are employed to clarify the structural origin of the fast Li ion migration kinetics in LAGP solid electrolytes. The calculated results show that doping of Al leads to an emerging high-energy 36 f Li site, which plays an important role in promoting the Li diffusion and can largely lower the Li ion diffusion energy barrier. Moreover, the Li/Al antisite defect is investigated firstly, with which the Li ions are excited to occupy a relatively high energy site in LAGP. The obvious local structural distortion by Li/Al antisite results in the coordination change upon Li diffusion(lattice field distortion), which facilitates the Li diffusion significantly and is probably the main reason to account for the superionic diffusion phenomenon. Therefore, the occupation of Li at high-energy sites should be an effective method to establish the fast Li diffusion, which implies a rewarding avenue to build better Li-ion batteries.
