Li_1.5La_1.5MO₆ (M?=?W⁶⁺, Te⁶⁺) as a new series of lithium-rich double perovskites for all-solid-state lithium-ion batteries.

ABSTRACT: Solid-state batteries are a proposed route to safely achieving high energy densities, yet this architecture faces challenges arising from interfacial issues between the electrode and solid electrolyte. Here we develop a novel family of double perovskites, Li_1.5La_1.5MO₆ (M?=?W⁶⁺, Te⁶⁺), where an uncommon lithium-ion distribution enables macroscopic ion diffusion and tailored design of the composition allows us to switch functionality to either a negative electrode or a solid electrolyte. Introduction of tungsten allows reversible lithium-ion intercalation below 1?V, enabling application as an anode (initial specific capacity >200 mAh g^-1 with remarkably low volume change of ?0.2%). By contrast, substitution of tungsten with tellurium induces redox stability, directing the functionality of the perovskite towards a solid-state electrolyte with electrochemical stability up to 5?V and a low activation energy barrier (<0.2?eV) for microscopic lithium-ion diffusion. Characterisation across multiple length- and time-scales allows interrogation of the structure-property relationships in these materials and preliminary examination of a solid-state cell employing both compositions suggests lattice-matching avenues show promise for all-solid-state batteries.

SUBMITTER: Amores M 

PROVIDER: S-EPMC7738526 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature