Screening metal tellurides as cathode materials for Li-Te batteries

Li-Te batteries are one of the best candidates for energy storage systems, while the shuttle effect of lithium polytellurides hinder their practical application. Designing novel cathode materials to reduce the dissolution of lithium polytellurides in the electrolyte is a crucial strategy for suppressing the shuttle effect. Metal tellurides can serve as promising tellurium host materials due to their polar interaction with lithium polytellurides. In this work, the adsorption and conversion of lithium polytellurides on seven kinds of metal tellurides (CoTe2, NbTe2, NiTe2, TiTe2, VTe2, MoTe2, WTe2) were explored by DFT calculation. Results show that the adsorption of metal tellurides with 1T phase is stronger than that of metal tellurides with 2H phase. Among these, CoTe2 can firmly anchor lithium polytellurides. Furthermore, CoTe2 exhibits the lowest conversion barrier of Te8 to Li2Te, indicating that it can significantly accelerate the electrochemical reaction dynamics and reduce the shuttle effect of lithium polytellurides. In addition, CoTe2 also shows strong binding energy and low diffusion activation energy for Li ions. Therefore, CoTe2 may be an excellent candidate for cathode materials of Li-Te batteries. These results are expected to guide the design of cathode materials for Li-Te batteries.

Automated summary

CoTe2 shows strong adsorption and conversion ability for lithium polytellurides, making it a promising cathode material for Li-Te batteries.