Improving lithium-ion battery performance through patterned growth of carbon nanotubes over vertically aligned silicon nanowires

Abstract

The pursuit of high-performance electrode materials for rechargeable energy storage systems has intensified recently. In this study, we introduce a novel fabrication method that precisely covers as-grown carbon nanotubes (CNTs) atop vertically aligned silicon nanowires (SiNWs), resulting in a unique CNT@SiNW hybrid structure. This innovative approach seeks to maximize the surface area of CNTs, with the ultimate goal of significantly enhancing the cycling stability of anodes in lithium-ion (Li-ion) batteries. The resulting hybrid structure exhibits a notably higher BET (Brunauer-Emmett-Teller) surface area, quantified at 150 m2/g, surpassing the 101 m2/g surface area of CNTs on silicon (Si) wafers. Moreover, the CNT@SiNW hybrid structure exhibits a larger pore size equal to 2.34 nm, compared to the 1.87 nm pore size observed for CNTs on Si wafers. Electrochemical assessments reveal the superior lithium storage performance of the CNT@SiNW hybrid structure compared to as-prepared CNTs electrodes. These improved electrochemical properties are primarily attributed to the synergistic effects between the CNTs and SiNW arrays, as well as the increased surface area of CNTs grown on the SiNW tips. Overall, the findings of this study strongly advocate for the promising potential of the CNT@SiNW hybrid structure as anode materials for high-performance energy storage devices.