An SiO_x anode strengthened by the self-catalytic growth of carbon nanotubes

Modification using carbon nanotubes (CNTs) is one of the most important strategies to boost the performance of materials in various applications, among which the CNT-modified silicon-based anodes have gained considerable attention in lithium-ion batteries (LIBs) due to their improved conductivity and cycle stability. However, the realization of a close-knit CNT coating on silicon (Si) through an efficient and cost-effective approach remains challenging. Herein, a new in situ self-catalytic method by acetylene treatment is presented, in which, CNTs can be directly grown and knitted on the SiO_x particles to construct a conductive additive-free SiO_x@CNT anode. The in situ grown CNTs can not only enhance electric conductivity and alleviate the volume effect of SiO_x effectively, but also mitigate the electrolyte decomposition with improved coulombic efficiency. As a result, an extremely high capacity of 1012 mA h g^-1, long lifespan over 500 cycles at a current density of 2 A g^-1 as well as a good performance in full LIBs with a working potential of about 3.4 V (vs. nickel-rich cathode) were obtained. The rationally constructed SiO_x@CNTs with easy synthesis and high throughput will hopefully promote LIBs with energy density above 300 W h kg^-1. This study opens a new avenue to prepare CNT-decorated functional materials and brings the SiO_x-based anode one step closer to practical applications.