Pitch-based carbon/nano-silicon composite, an efficient anode for Li-ion batteries

• Published in: RSC advances Vol. 9; no. 19; pp. 10546 - 10553
• Main Authors: Escamilla-Pérez, Angel Manuel, Roland, Aude, Giraud, Sophie, Guiraud, Céline, Virieux, Héloïse, Demoulin, Kévin, Oudart, Yohan, Louvain, Nicolas, Monconduit, Laure
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 04.04.2019; The Royal Society of Chemistry
• Subjects: Anodes; Argon; Carbon; Chemical Sciences; Chemistry; Coating effects; Composite materials; Cycles; Electrochemical analysis; Electrode materials; Electrodes; Lithium; Lithium-ion batteries; Material chemistry; Nanoparticles; Pyrolysis; Rechargeable batteries; Silicon; Stability
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c9ra00437h

As silicon-carbon electrodes with low silicon ratio are the negative electrode foreseen by battery manufacturers for the next generation of Li-ion batteries, a great effort has to be made to improve their efficiency and decrease their cost. Pitch-based carbon/nano-silicon composites are proposed as a high performance and realistic electrode material of Li-ion battery anodes. Composites are prepared in a simple way by the pyrolysis under argon atmosphere of silicon nanoparticles, obtained by a laser pyrolysis technique, and a low cost carbon source: petroleum pitch. The effect of the size and the carbon coating of the silicon nanoparticles on the electrochemical performance in Li-ion batteries is highlighted, proving that the carbon coating enhances cycling stability. Helped by a homogeneous dispersion of silicon nanoparticles into the amorphous carbon matrix, a high coulombic efficiency (especially in the first cycle) and a high stability over cycling is observed (over 1100 mA h g after 100 cycles at relatively high current density 716 mA g for Si based electrodes), which are superior to pitch-based carbon/silicon composites found in literature. This simple synthesis method may be extrapolated to other electrode active materials.