Rational design of 2D blue phosphorene/Ti2BT2 (T=Se, Te) heterostructures as high-performance anode materials for alkali-metal ion batteries: A first principles study

Blue phosphorene (BlueP) is extensively regarded as an attractive anode for the next generation of metal-ion batteries (MIBs) owing to the rapid ion diffusion and high storage capacity; however, its electrochemical performance is still seriously impeded by the intrinsically low conductivity and poor mechanical stiffness. To overcome the above obstacles, we theoretically designed BlueP/Ti2BSe2 and BlueP/Ti2BTe2 heterostructures, and explored their potential as the anodes of MIBs using first principles calculations. The computational results demonstrate that the resulting heterostructures have excellent thermal and mechanical stability. Moreover, the designed two heterostructures show low ion diffusion barrier (<0.30 eV) with inherent metallicity, which greatly contributes to the rate performance of MIBs. Remarkably, the BlueP/Ti2BSe2 (BlueP/Ti2BTe2) anode delivers high Li/Na/K storage capacities of 492.68 (379.54)/410.54 (379.54)/191.59 mA h/g, and suitable averaged open circuit voltages (OCVs) of 0.56 (0.33)/0.33 (0.10)/0.42 V. This work not only broadens the BlueP-based 2D heterostructures, but also lays a solid foundation for the theoretical design of exceptional anodes.