Imperial College London
Alternate

ProfessorJohnKilner

Faculty of Engineering, Department of Materials

Senior Research Investigator
 
 
 
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Contact

 

+44 (0)20 7594 6745j.kilner Website

 
 
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Location

 

214Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Buannic:2017:10.1021/acs.chemmater.6b05369,
author = {Buannic, L and Orayech, B and Lopez, Del Amo J-M and Carrasco, J and Katcho, NA and Aguesse, F and Manalastas, W and Zhang, W and Kilner, J and Llordes, A},
doi = {10.1021/acs.chemmater.6b05369},
journal = {CHEMISTRY OF MATERIALS},
pages = {1769--1778},
title = {Dual Substitution Strategy to Enhance Li+ Ionic Conductivity in Li7La3Zr2O12 Solid Electrolyte},
url = {http://dx.doi.org/10.1021/acs.chemmater.6b05369},
volume = {29},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Solid state electrolytes could address the current safety concerns of lithium-ion batteries as well as provide higher electrochemical stability and energy density. Among solid electrolyte contenders, garnet-structured Li7La3Zr2O12 appears as a particularly promising material owing to its wide electrochemical stability window; however, its ionic conductivity remains an order of magnitude below that of ubiquitous liquid electrolytes. Here, we present an innovative dual substitution strategy developed to enhance Li-ion mobility in garnet-structured solid electrolytes. A first dopant cation, Ga3+, is introduced on the Li sites to stabilize the fast-conducting cubic phase. Simultaneously, a second cation, Sc3+, is used to partially populate the Zr sites, which consequently increases the concentration of Li ions by charge compensation. This aliovalent dual substitution strategy allows fine-tuning of the number of charge carriers in the cubic Li7La3Zr2O12 according to the resulting stoichiometry, Li7–3x+yGaxLa3Zr2–yScyO12. The coexistence of Ga and Sc cations in the garnet structure is confirmed by a set of simulation and experimental techniques: DFT calculations, XRD, ICP, SEM, STEM, EDS, solid state NMR, and EIS. This thorough characterization highlights a particular cationic distribution in Li6.65Ga0.15La3Zr1.90Sc0.10O12, with preferential Ga3+ occupation of tetrahedral Li24d sites over the distorted octahedral Li96h sites. 7Li NMR reveals a heterogeneous distribution of Li charge carriers with distinct mobilities. This unique Li local structure has a beneficial effect on the transport properties of the garnet, enhancing the ionic conductivity and lowering the activation energy, with values of 1.8 × 10–3 S cm–1 at 300 K and 0.29 eV in the temperature range of 180 to 340 K, respectively.
AU  - Buannic,L
AU  - Orayech,B
AU  - Lopez,Del Amo J-M
AU  - Carrasco,J
AU  - Katcho,NA
AU  - Aguesse,F
AU  - Manalastas,W
AU  - Zhang,W
AU  - Kilner,J
AU  - Llordes,A
DO  - 10.1021/acs.chemmater.6b05369
EP  - 1778
PY  - 2017///
SN  - 0897-4756
SP  - 1769
TI  - Dual Substitution Strategy to Enhance Li+ Ionic Conductivity in Li7La3Zr2O12 Solid Electrolyte
T2  - CHEMISTRY OF MATERIALS
UR  - http://dx.doi.org/10.1021/acs.chemmater.6b05369
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000395358600036&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/45853
VL  - 29
ER  -
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