Amores Marco, El-Shinawi Hany, McClelland Innes, Yeandel Stephen R, Baker Peter J, Smith Ronald I, Playford Helen Y, Goddard Pooja, Corr Serena A, Cussen Edmund J
Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, S1 3JD, UK.
The Faraday Institution, Harwell Campus, Didcot, OX1 0RA, UK.
Nat Commun. 2020 Dec 15;11(1):6392. doi: 10.1038/s41467-020-19815-5.
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, LiLaMO (M = W, Te), 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 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.
固态电池是一种有望安全实现高能量密度的途径，然而这种架构面临着电极与固体电解质之间界面问题所引发的挑战。在此，我们开发了一类新型的双钙钛矿LiLaMO（M = W、Te），其中不常见的锂离子分布实现了宏观离子扩散，且成分的定制设计使我们能够将功能切换为负极或固体电解质。引入钨可使锂离子在1 V以下进行可逆嵌入，从而能够用作阳极（初始比容量>200 mAh g，体积变化极低，约为0.2%）。相比之下，用碲取代钨可诱导氧化还原稳定性，使钙钛矿的功能转向固态电解质，其具有高达5 V的电化学稳定性以及用于微观锂离子扩散的低活化能垒（<0.2 eV）。跨多个长度和时间尺度的表征有助于探究这些材料中的结构-性能关系，并且对采用这两种成分的固态电池进行的初步研究表明，晶格匹配途径对全固态电池具有前景。
