Evaluation of the effect of site substitution of Pr doping in the Lithium garnet system Li5La3Nb2O12

DOI: 10.1039/D0DT01497D

Authors: Mark P. Stockham (University of Birmingham) , Bo Dong (University of Birmingham) , Yongliang Li (University of Birmingham) , Yulong Ding (University of Birmingham) , Peter Slater (University of Birmingham)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Dalton Transactions

State: Published (Approved)
Published: May 2020
Diamond Proposal Number(s): 14239

Abstract: Li ion conducting garnets have been attracting considerable interest for use as the electrolyte in all solid-state batteries, due to their high ionic conductivity and wide electrochemical stability window. Consequently, there have been a number of doping studies aimed at optimising the conductivity, focusing on both doping in Li7La3Zr2O12 and Li5La3(Nb/Ta)2O12 systems. In this paper, we report a detailed study of Pr doping in Li5La3Nb2O12, and show that this is a rare example of an ambi-site dopant, being able to be doped onto either the La or Nb site. Interestingly the resultant Pr oxidation state is determined by the site substitution, with oxidation states of 3+ for the La site, and 4+ for the Nb site. While the conductivity is essentially unchanged for the La site substitution, Pr4+ substitution on the Nb site leads to a large increase in the conductivity associated with the increase in Li content (Li5+xLa3Nb2-xPrxO12) up to 0.56 mScm-1 (at 50˚C) for x=0.8. Overall, this work highlights the flexibility of these garnet materials to doping, and suggests that further consideration of site substitution be considered for other dopants.

Journal Keywords: garnet; lithium; praseodymium; ambi-site dopant

Diamond Keywords: Batteries; Lithium-ion

Subject Areas: Chemistry, Materials, Energy


Instruments: B18-Core EXAFS

Added On: 04/06/2020 08:37

Documents:
d0dt01497d.pdf

Discipline Tags:

Energy Storage Energy Physical Chemistry Energy Materials Chemistry Materials Science

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) X-ray Absorption Near Edge Structure (XANES)