Enhancing first-principles simulations of complex solid-state ion conductors using topological analysis of procrystal electron density

Abstract

Atomistic-level understanding of ion migration mechanisms holds the key to design high-performance solid-state ion conductors for a breadth of electrochemical devices. First-principles simulations play an important role in this quest. Yet, these methods are generally computationally-intensive, with limited access to complex, low-symmetry structures, such as interfaces. Here we show how topological analysis of the procrystal electron density can be applied to efficiently mitigate this issue. We discuss how this methodology goes beyond current state of the art capabilities and demonstrate this with two examples. In the first, we examine Li-ion transport across grain boundaries in Li3ClO electrolyte. Then, we compute diffusion coefficients as a function of charge carrier concentration in spinel LiTiS2 electrode material. These two case studies do not exhaust the opportunities and might constitute motivations for still more complex applied materials.