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Simultaneous Carbon Coating and Lithiation of Oxides by Contact Reaction
Author(s) -
Wächter Florian,
Krumeich Frank,
Nesper Reinhard
Publication year - 2014
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201304913
Subject(s) - lithium (medication) , materials science , raman spectroscopy , carbon fibers , coating , electrochemistry , acetylide , chemical engineering , amorphous solid , amorphous carbon , transmission electron microscopy , cathode , glassy carbon , electrode , nanotechnology , composite material , chemistry , composite number , cyclic voltammetry , organic chemistry , photochemistry , medicine , physics , engineering , optics , endocrinology
Chemical lithiation and carbon coating of cathode materials can lead to strongly improved electrochemical properties, especially if the active materials have low electronic conductivity. This behavior is quite often the case for new high‐capacity materials. A novel synthesis method is presented in which the two processes are performed simultaneously by employing Li 2 C 2 as both the carbon and the lithium source. In this contact reaction, the acetylide anion C 2 2− is oxidized to carbon and deposited directly on the surface of the active material, while lithium is reductively inserted into the oxidant. Two different synthesis routes are demonstrated: a tribochemical approach at room temperature and heat treatments between 150 and 600 °C. The applicability of these new carbon‐coating methods are demonstrated on various crystalline and amorphous Li x V 2 O 5 phases. The composites obtained were characterized by powder X‐ray diffraction, transmission electron microscopy, and Raman spectroscopy. In addition, electrochemical data confirm the chemical lithiation and show that lithiated Li x V 2 O 5 with specific phases can be prepared selectively.