First‐principle calculation of distorted T‐carbon as a promising anode for Li‐ion batteries with enhanced capacity, reversibility, and ion migration properties

Abstract

Abstract Carbon group element‐based materials are the most widely used anode materials for Li‐ion batteries (LIBs). However, their performance is limited by the low capacity (eg, graphite) or high‐volume changes (eg, Si and Sn). Therefore, exploring high‐performance anode materials is quite appealing and promising. By first‐principle calculations in this study, we found that distorted T‐carbon (DTC) as a desired LIB anode shows properties of the enhanced capacity, decreased volume change, and the increased ion migration. The origin of such improved properties is attributed to the interconnected tunnels and large cavities of the carbon skeleton. The theoretical specific capacity of DTC is found to be 558 mAh/g, which is 1.5 times higher than that of commercial graphite anodes. Interestingly, the volume change of the DTC anode is only 3% at the full‐lithiation state (one‐fifth of that of the commercial graphite anode), which can overcome the pulverization problem in most high‐capacity anode materials and attain a longer cycling lifetime. Both transition state calculations and molecular dynamics simulations demonstrate that the Li‐ion migration barrier is less than 0.1 eV and the Li‐ion vacancy is only 0.2 eV, enabling its promising rate performance. This study provides a new and effective strategy to improve the anode properties of LIBs.

Keywords

• density functional theory
• Li‐ion batteries
• molecular dynamics
• nanomaterials
• T‐carbon