Electrochemical lithiation of Ge: New insights by operando spectroscopy and diffraction
Journal article, 2018
The relatively high cost of metallic germanium (Ge) as a lithium-ion battery negative electrode material is more than counterbalanced by its high capacity, high lithium diffusivity, and electronic conductivity. Using a unique and highly complementary set of operando characterization techniques, we propose a complete mechanism for the reversible lithiation of Ge. The electrochemical mechanism is found to be determined by the process of discharge/charge: (i) independent of the charge/discharge rate amorphous a-LiGe is proposed as the first intermediate during the lithiation of c-Ge, followed by Li 7 Ge 3 , and (ii) at low potential Li 15 Ge 4 is observed, but only for moderate rates and never at low rates, where indeed an "overlithiated" phase is preferred. The complementarity of the data obtained from XAS, Raman spectroscopies, and XRD, all in operando mode, was crucial in order to understand the complex mechanism based on reversible formation of the various crystalline and amorphous phases.
Author
L. C. Loaiza
University of Picardie Jules Verne
N. Louvain
University of Montpellier
Centre national de la recherche scientifique (CNRS)
B. Fraisse
University of Montpellier
Athmane Boulaoued
University of Montpellier
Chalmers, Physics, Condensed Matter Physics
A. Iadecola
Centre national de la recherche scientifique (CNRS)
Patrik Johansson
Chalmers, Physics, Condensed Matter Physics
L. Stievano
University of Montpellier
Centre national de la recherche scientifique (CNRS)
V. Seznec
University of Picardie Jules Verne
Centre national de la recherche scientifique (CNRS)
L. Monconduit
University of Montpellier
Centre national de la recherche scientifique (CNRS)
Journal of Physical Chemistry C
1932-7447 (ISSN) 1932-7455 (eISSN)
Vol. 122 7 3709-3718Subject Categories
Inorganic Chemistry
Materials Chemistry
Other Physics Topics
Other Chemistry Topics
Driving Forces
Sustainable development
Areas of Advance
Transport
Energy
Materials Science
DOI
10.1021/acs.jpcc.7b11249