γ-Graphyne nanotubes as promising lithium-ion battery anodes

Abstract

Developing novel carbon-based lithium-ion battery (LIB) anodes has been an active field of research over the last decade. Because of their large surface area and good chemical/mechanical properties, two-dimensional graphyne materials have proved to be good candidates. However, graphyne nanotubes (GyNTs), which are derivatives of graphyne, have received little attention in this area of research. Herein, we carried out density functional theory calculations to explore the applicability of γGyNTs as LIB anodes. Our results show that all studied γGyNTs have better maximum storage capacities compared to single-layered or multiple-layered γ-graphyne, and (2, 2)-γGyNT has the largest storage capacity of C6Li6 (2232 mAh·g−1). The good storage capacities of γGyNTs are proposed to be the result of curvature-induced orbital rearrangement. In addition, this curvature can promote the diffusion and migration of Li atoms, thus improving performance.