V2O3/C composite fabricated by carboxylic acid-assisted sol–gel synthesis as anode material for lithium-ion batteries

• Published in: Journal of sol-gel science and technology Vol. 98; no. 3; pp. 549 - 558
• Main Authors: Zakharova, G. S., Thauer, E., Enyashin, A. N., Deeg, L. F., Zhu, Q., Klingeler, R.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2021; Springer Nature B.V
• Subjects: Acids; Anodes; Carbon; Carboxylic acids; Ceramics; Chelating agents; Chelation; Chemistry and Materials Science; Citric acid; colloids; Composites; Electrochemical analysis; Electrode materials; etc.; fibers; Glass; Grain boundaries; Inorganic Chemistry; Lithium; Lithium-ion batteries; Malic acid; Materials Science; Microparticles; Morphology; Nanocomposites; Nanotechnology; Natural Materials; Optical and Electronic Materials; Organic acids; Original Paper: Nano-structured materials (particles; Phase separation; Quantum chemistry; Raman spectroscopy; Rechargeable batteries; Sol-gel processes; Stability analysis; Tartaric acid; Vanadium oxides; Anode material; Lithium-ion batteries; Composites; Sol–gel processes; V; O
• DOI: 10.1007/s10971-021-05523-z
• ISSN: 0928-0707

The potential battery electrode material V 2 O 3 /C has been prepared using a sol–gel thermolysis technique, employing vanadyl hydroxide as precursor and different organic acids as both chelating agents and carbon sources. Composition and morphology of resultant materials were characterized by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopies, physical sorption, and elemental analysis. Stability and electronic properties of model composites with chemically and physically integrated carbon were studied by means of quantum-chemical calculations. All fabricated composites are hierarchically structured and consist of carbon-covered microparticles assembled of polyhedral V 2 O 3 nanograins with intrusions of amorphous carbon at the grain boundaries. Such V 2 O 3 /C phase separation is thermodynamically favored while formation of vanadium (oxy)carbides or heavily doped V 2 O 3 is highly unlikely. When used as anode for lithium-ion batteries, the nanocomposite V 2 O 3 /C fabricated with citric acid exhibits superior electrochemical performance with an excellent cycle stability and a specific charge capacity of 335 mAh g −1 in cycle 95 at 100 mA g −1 . We also find that the used carbon source has only minor effects on the materials’ electrochemical performance. Highlights V 2 O 3 /C composites were synthesized by a facile sol–gel thermolysis method. Citric acid, malic acid, and tartaric acid have been applied as both the chelating agents and as carbon source to produce V 2 O 3 /C composites for the first time. DFT calculations confirmed preference of phase separation in C-doped V 2 O 3 . V 2 O 3 /C composites as anode material exhibit an excellent cycle stability.