A multilayer Si/CNT coaxial nanofiber LIB anode with a high areal capacity

Abstract

Si/carbon nanotube (CNT) nanocomposites are ideal anode materials for lithium ion batteries with high specific capacities. However, it has been a significant challenge to fabricate uniform Si/CNT nanocomposite anodes with high areal capacities, say above 0.4 mA h cm⁻². In this paper, we demonstrate a layer-by-layer assembling technique as a facile and scalable method to prepare a multilayer Si/CNT coaxial nanofiber anode which possesses an areal storage capacity above 1 mA h cm⁻². In addition, the prepared Si/CNT coaxial nanofiber anodes show an excellent cyclability. The excellent performance of the Si/CNT coaxial nanofiber multilayer anodes is attributed to the unique nanostructure. The CNT network matrix offers mechanical support to accommodate the stress associated with the large volume change of Si coating and the nanoporous multilayer structure provides continuous paths for Li ion and electron transport.