Abstract
This work reports a computer modeling comparison of two solid electrolyte materials, LiPO and LiPS, in terms of the bulk structures, Li ion mobilities, and their interface properties with vacuum and with Li metal. The simulations show that for some forms of LiPS, Li ions can move from a host lattice site to an interstitial site with negligible net energy change. This favorable process for the formation of vacancy-interstitial pairs is undoubtedly important for the structural and ion migration properties of -LiPS. Our model results for the idealized interfaces between the electrolytes and Li metal show that LiPO /Li interfaces are stable, while LiPS /Li interfaces are not. We find that a LiPS surface in the presence of a small amount of Li relaxes to a complicated structure involving broken P-S bonds. On the other hand, the computer models show that a very thin film of LiS on the LiPS surface can provide a protective buffer layer to stabilize the interface between the LiPS electrolytes and the Li metal anode.
7 More- Received 4 July 2013
DOI:https://doi.org/10.1103/PhysRevB.88.104103
©2013 American Physical Society