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

Centre national de la recherche scientifique (CNRS)

University of Montpellier

V. Seznec

University of Picardie Jules Verne

Centre national de la recherche scientifique (CNRS)

L. Monconduit

Centre national de la recherche scientifique (CNRS)

University of Montpellier

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 122 7 3709-3718

Subject Categories

Inorganic Chemistry

Materials Chemistry

Other Chemistry Topics

Driving Forces

Sustainable development

Areas of Advance

Transport

Energy

Materials Science

DOI

10.1021/acs.jpcc.7b11249

More information

Latest update

1/6/2019 1