Fast carrier diffusion synergistic effects between lithium-ions and polarons in rutile TiO.

Carrier mobility in titanium dioxide (TiO) systems is a key factor for their application as energy materials, especially in solar cells and lithium-ion batteries. Studies on the diffusion of Li-ions and polarons in rutile TiO systems have attracted extensive attention. However, how their interaction affects the diffusion of Li-ions and electron polarons is largely unclear and related studies are relatively lacking. By using first-principles calculations, we systematically investigate the interaction between the intercalated Li-ions and electron polarons in rutile TiO materials. Our analysis shows that the diffusion barrier of the electron polarons decreases around the Li-ion. The interaction between the Li-ions and polarons would benefit their synergistic diffusion both in the pristine and defective rutile TiO systems. Our study reveals the synergistic effects between the ions and polarons, which is important for understanding the carrier properties in TiO systems and in further improving the performance of energy materials.