| 摘要： |
Density functional theory simulations and experimental studies were performed to investigate the interfacial properties, including Lithium ion migration kinetics, between Lithium metal anode and saki electrolyte Li10GeP2S12(LGPS). The LGPS[001] Wane was chosen as the studied surface because the easiest Li+ migration pathway is along this direction. The electronic structure of the surface states indicated that the electrochemical stability was reduced at both the PS4- and GeS4-teminated surfaces. For the interface cases, the equilibrium interfacial structures of Lithium metal against the PS4-terminated LGPS[001] surface (Li/PS4 LGPS) and the GeS4-terminated LGPS[001] surface (Li/GeS4 LGPS) were revealed based on the structural relaxation and adhesion energy analysis. Solid electrolyte interphases were expected to be formed at both Li/PS4- LGPS and Li/GeS4-LGPS interfaces, resulting in an unstable state of interface and Large interfacial resistance, which was verified by the EIS results of the Li/LGPS/Li cell. In addition, the simulations of the migration kinetics show that the energy barriers for Li+ crossing the Li/GeS4 LGPS interface were relatively Low compared with the Li/PS4 LGPS interface. This may contribute to the formation of Ge-rich phases at the Li/LGPS interface, which can tune the interfacial structures to improve the ionic conductivity for future all-solid-state batteries. This work will offer a thorough understanding of the Li/LGPS interface, including local structures, electronic states and Li+ diffusion behaviors in all-solid-state batteries. |
