1. An environment-friendly approach to produce nanostructured germanium anodes for lithium-ion batteries
- Author
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Alexey S. Galushko, Mikhail A. Syroeshkin, Pavel A. Troshin, Mikhail P. Egorov, Visweshwar Sivasankaran, Roman R. Kapaev, Viatcheslav Jouikov, Evgeniya A. Saverina, Valentine P. Ananikov, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Skolkovo Institute of Science and Technology [Moscow] (Skoltech), ND Zelinsky Institute of Organic Chemistry [Moscow, Russia], Russian Science FoundationRussian Science Foundation (RSF) [16-13-00111, 17-73-20281], Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,chemistry.chemical_element ,Germanium ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,law.invention ,symbols.namesake ,chemistry.chemical_compound ,law ,[CHIM]Chemical Sciences ,Environmental Chemistry ,Electrolysis ,Germanium dioxide ,021001 nanoscience & nanotechnology ,Pollution ,Nanocrystalline material ,0104 chemical sciences ,Anode ,chemistry ,Chemical engineering ,symbols ,Lithium ,Cyclic voltammetry ,0210 nano-technology ,Raman spectroscopy - Abstract
International audience; In this paper, we propose a halogen-free process for the preparation of germanium micro-scale particles with a nano-structured surface morphology from germanium citrate, an easily accessible and environment-friendly precursor formed from germanium dioxide and citric acid in an aqueous medium. Electrodeposition of nanostructured Ge anodes on copper foil was performed via electrolysis of 1-5% germanium citrate solution in propylene glycol with addition of 5% acetic acid. Cyclic voltammetry data suggested that germanium citrate is an electrochemically inactive compound, but readily undergoes reduction by cathodic hydrogen released in the electrolysis. Such behaviour allows one to run the electrolysis under simple galvanostatic conditions without any need for controlling the potential. Furthermore, no diaphragm is required to separate the cathodic and anodic cell compartments. The electrodeposition produces black and compact films composed of similar to 200 nm germanium particles, which, in turn, consist of nanoparticles no larger than 25 nm in size (SEM and TEM data). XRD and Raman spectroscopy data lead to the conclusion that germanium precipitates in the amorphous phase; however, with an increase in the power of the He-Ne laser (632.8 nm) during Raman spectra recording, it transforms into a nanocrystalline form. Testing germanium anodes in lithium-ion half-cells showed a specific capacity of similar to 600 mA h g(-1) at 1-2C current rates, which is comparable to the best results achieved for Ge anodes produced using more sophisticated and less environment-friendly techniques.
- Published
- 2020
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