A silicon-impregnated carbon nanotube mat as a lithium-ion cell anode

• Published in: Journal of applied electrochemistry Vol. 48; no. 1; pp. 127 - 133
• Main Authors: Ho, David N., Yildiz, Ozkan, Bradford, Philip, Zhu, Yuntian, Fedkiw, Peter S.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 2018; Springer Nature B.V
• Subjects: Batteries; Carbon; Carbon black; Carbon nanotubes; Cell anodes; Charge transfer; Chemistry; Chemistry and Materials Science; Electric cells; Electrochemistry; Guar gum; Industrial Chemistry/Chemical Engineering; Lithium; Lithium-ion batteries; Nanoparticles; Nanotubes; Physical Chemistry; Rechargeable batteries; Short Communication; Silicon; Slurries; Lithium-ion batteries; Silicon anodes; Hydroxypropyl guar gum; Novel fabrication technique; Carbon nanotube mat
• ISSN: 0021-891X; 1572-8838
• DOI: 10.1007/s10800-017-1140-8

Silicon is a widely researched material for the anodes of lithium-ion batteries due to its high practical charge capacity of 3600 mAh g −1 , which is ~ 10 times the specific capacity of conventional graphitic materials. However, silicon degrades rapidly in use due to its volumetric changes during charge/discharge of the battery, which makes it necessary to use complicated or costly methods to ameliorate capacity loss. Here, we report a novel silicon anode fabrication technique, which involves winding an aligned carbon nanotube (CNT) sheet and commensurately infiltrating it in situ with an aqueous solution containing silicon nanoparticles and hydroxypropyl guar binder. The resulting infiltrated felts were processed, evaluated, and compared to conventional silicon–carbon black anodes with the same carbon, silicon, and binder content as a proof of concept study. The felts had a large initial reversible capacity and promising rate capability. It is likely that the conductive CNT structure improved the charge transfer properties while lessening the effects of silicon volumetric expansion during lithiation. The results demonstrate that this novel anode fabrication method is viable and may be explored for further optimization. Graphical Abstract A novel fabrication method is described for the negative electrode for a lithium-ion battery: a CNT mat is formed by a drawing operation from a CNT vertical array while simultaneously being impregnated with a solution containing silicon nanoparticles and hydroxypropyl guar gum binder. The resulting CNT–Si anode structure shows improved lifetime cycling performance compared to traditional slurry-based silicon anodes.