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Lithium Garnet Li 7 La 3 Zr 2 O 12 Electrolyte for All‐Solid‐State Batteries: Closing the Gap between Bulk and Thin Film Li‐Ion Conductivities
Author(s) -
Sastre Jordi,
Priebe Agnieszka,
Döbeli Max,
Michler Johann,
Tiwari Ayodhya N.,
Romanyuk Yaroslav E.
Publication year - 2020
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.202000425
Subject(s) - materials science , electrolyte , ionic conductivity , lithium (medication) , conductivity , fast ion conductor , fabrication , ceramic , thin film , pellets , chemical engineering , analytical chemistry (journal) , mineralogy , nanotechnology , electrode , metallurgy , composite material , chemistry , medicine , alternative medicine , pathology , chromatography , engineering , endocrinology
The high ionic conductivity and wide electrochemical stability of the lithium garnet Li 7 La 3 Zr 2 O 12 (LLZO) make it a viable solid electrolyte for all‐solid‐state lithium batteries with superior capacity and power densities. Contrary to common ceramic processing routes of bulk pellets, thin film solid electrolytes could enable large‐area fabrication, and increase energy and power densities by reducing the bulkiness, weight and critically, the area‐specific resistance of the electrolyte. Fabrication of LLZO films has nonetheless been challenging because of lithium losses and formation of impurity phases that result in low densities and poor ionic conductivities as compared to bulk pellets. Here, a scalable method for fabricating submicron films of LLZO employing co‐sputtering from doped LLZO and Li 2 O targets is presented. A record ionic conductivity of 1.9 × 10 −4 S cm –1 is measured for dense and uniform cubic‐phase Ga‐substituted LLZO films annealed at 700 °C in oxygen, which is comparable to the values in high‐temperature sintered pellets and outperforms by one order of magnitude the latest record for LLZO thin films as well as the typical conductivities in the well‐established LiPON electrolyte. This result is an important milestone to realize all‐vacuum deposited solid‐state batteries with higher power density.