X-ray pair distribution function analysis and electrical and electrochemical properties of cerium doped Li 5La 3Nb 2O 12garnet solid-state electrolyte

Research output: Contribution to journalArticlepeer-review

Authors

Colleges, School and Institutes

External organisations

  • Diamond Light Source

Abstract

Garnet solid state electrolytes have been considered as potential candidates to enable next generation all solid state batteries (ASSBs). To facilitate the practical application of ASSBs, a high room temperature ionic conductivity and a low interfacial resistance between solid state electrolyte and electrodes are essential. In this work, we report a study of cerium doped Li5La3Nb2O12 through X-ray pair distribution function analysis, impedance spectroscopy and electrochemical testing. The successful cerium incorporation was confirmed by both X-ray diffraction refinement and X-ray pair distribution function analysis, showing the formation of an extensive solid solution. The local bond distances for Ce and Nb on the octahedral site were determined using X-ray pair distribution function analysis, illustrating the longer bond distances around Ce. This Ce doping strategy was shown to give a significant enhancement in conductivity (1.4 × 10-4 S cm-1 for Li5.75La3Nb1.25Ce0.75O12, which represents one of the highest conductivities for a garnet with less than 6 Li) as well as a dramatically decreased interfacial resistance (488 Ω cm2 for Li5.75La3Nb1.25Ce0.75O12). In order to demonstrate the potential of this doped system for use in ASSBs, the long term cycling of a Li//garnet//Li symmetric cell over 380 h has been demonstrated.

Details

Original languageEnglish
Pages (from-to)11727-11735
Number of pages9
JournalDalton Transactions
Volume49
Issue number33
Early online date10 Aug 2020
Publication statusPublished - 7 Sep 2020

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