Two-Dimensional Tetragonal Titanium Carbide: a High-Capacity and High-Rate Battery Material

High-performance electrode materials are critical for the development of next-generation energy conversion and storage systems. Herein, we report a theoretical design of novel two-dimensional materials, namely, tetragonal titanium carbide and nitride (tetr-TiC and tetr-TiN) based on ab initio calculations. State-of-the-art calculations show that tetr-TiC and tetr-TiN deliver the intrinsic metallic nature, high thermal stability, and satisfactory lithium-ion storage and rate capability. More importantly, compared with previously known Ti3C2 and Ti2C sheets, the proposed new material has lower Li diffusion barrier, higher theoretical capacity, and lower average open circuit. Combining such advanced features, the proposed tetragonal TiC is a promising candidate for future lithium-ion batteries, supercapacitors, and fuel cells.