Physical Review Applied
Using first-principles calculations, we evaluate the electrochemical performance of heterostructures made up of Ti2CO2 and chemically modified graphene for Li batteries. We find that heteroatom doping and molecule intercalation have a significant impact on the storage capacity and Li migration barrier energies. While N and S doping do not improve the storage capacity, B doping together with molecule interaction make it possible to intercalate two layers of Li, which stick separately to the surface of Ti2CO2 and B-doped graphene. The calculated diffusion-barrier energies (Ediff), which are between 0.3 and 0.4 eV depending on Li concentration, are quite promising for fast charge and discharge rates. Besides, the predicted Ediff as much as 2 eV for the diffusion of the Li atom from the Ti2CO2 surface to the B-doped graphene surface significantly suppresses the interlayer Li migration, which diminishes the charge and discharge rates. The calculated volume and lattice parameter changes indicate that Ti2CO2/graphene hybrid structures exhibit cyclic stability against Li loading and unloading. Consequently, first-principles calculations we perform evidently highlight the favorable effect of molecular intercalation on the capacity improvement of ion batteries.
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Sevik, Cem and Cakir, Deniz, "Tailoring Storage Capacity and Ion Kinetics in Ti 2 CO 2 / Graphene Heterostructures by Functionalization of Graphene" (2019). Physics Faculty Publications. 2.