First-principles calculations study of TiS2/Ti2CS2 heterostructure as an anode material for Li/Na/K-ion batteries

Abstract

TiS2 and Ti2CS2 are two potential candidates as anode materials for rechargeable ion batteries. However, the issues of semiconductor property and re-stacking prevent their development. In this work, we assembled a van der Waals heterostructure of TiS2/Ti2CS2 and investigated its possibility as an anode material for Li/Na/K-ion batteries (LIBs/NIBs/KIBs) by first-principles calculations. The results show that the TiS2/Ti2CS2 has excellent stability and metallic nature. The Li, Na and K ions exhibit extremely low diffusion barriers (below 0.4 eV) in the TiS2/Ti2CS2 interlayer, which predicts that it has remarkable rate performance. For NIBs and KIBs, the average open circuit voltages (0.626 V and 0.995 V) of TiS2/Ti2CS2 are in the range of 0–1 V and the theoretical specific capacities (566 mA·h/g and 283 mA·h/g) are higher than those (35 mA·h/g and 279 mA·h/g) of graphite anode for the corresponding batteries. All of this indicate that the TiS2/Ti2CS2 is well suited as an anode material for NIBs and KIBs. Our study may provide guidance and new ideas for the theoretical and experimental design of new anode materials for metal-ion batteries.