First-principles study on interfacial performance of Cl, Br and O-doped Li3PS4 against lithium for all-solid-state batteries

High interfacial resistance for electrode and solid-state electrolyte severely limits development of all-solid-state battery (ASSB). Sulfide type electrolytes are believed to be promising electrolytes for ASSBs, however, atomic-scale interfacial performance of the electrolytes and Li metal was not fully investigated so far. In this paper, first principles simulations are performed to evaluate interfacial properties of Cl, Br and O-doped Li3PS4 against lithium electrode for ASSB. It is observed that the PS3Cl and PS3Br tetrahedral in Cl and Br doped structures were destroyed near the interfaces, while the presence of O smooths the interface without damaging of PS3O tetrahedral. Based on the calculated thermodynamic stability, exchange energy and electronic properties of the Li-electrode and LPS-based electrolytes interfaces, LPSO/Li interface shows high interfacial stability without obvious formation of solid electrolyte interphase. The calculated migration energies barriers indicate that the doping of Cl, Br and O makes primary contribution for increasing lithium-ion diffusion performance, in particular, the energy barrier of lithium at LPSO/Li interface is the lowest and it corresponds fast Li-ion conduction.