Tuning the adsorption and diffusion capabilities of titanium disulfide monolayers by doping and strain engineering: Implications for lithium-ion batteries

Doping and strain engineering are effective tuning approaches for improving the electrochemical performance of materials in batteries and catalytic applications. This work investigates the adsorption and diffusion properties of lithium (Li) atoms on two-dimensional (2D) titanium disulfide (TiS 2 ) using first-principles calculations. This work also investigates the effects of strain and heteroatom doping with manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), and copper (Cu) on the performance of 2D TiS 2 and the prospects for its use in Li-ion batteries. Compared to other 2D materials such as VS 2 and MoS 2 , our findings reveal that pristine TiS 2 has a strong Li-ion adsorption energy of −2.03 eV, which improves to −2.07 eV and −2.62 eV by strain and doping, respectively. While no noticeable decrease in the diffusion energy barrier of the material is observed due to strain, the substitution of Ti with Co atoms results in a considerable reduction in the energy barrier from 0.19 eV to 0.12 eV. We also observed a dramatic enhancement of the open circuit voltage by ∼ 43% when a tensile strain of 4% is applied, and by ∼ 54% when the Co doping concentration is increased to 22.2%. The results indicate that 2D TiS 2 is a potential contender for battery anodes as well as electrocatalytic applications, with doping and strain engineering further enhancing the properties of the material. • DFT study of Li-ion adsorption and diffusion on pristine, strained and doped TiS 2 . • Doping significantly enhances the adsorption of Li ions on the surface of TiS 2 . • TiS 2 doped with Co atoms has a low Li-ion diffusion barrier and a high capacity.