Presentation by Hristo Rasheev
Electrode-electrolyte interface in metal-ion batteries – a stage for intriguing passions
Hristo Rasheev*, Radostina Stoyanova*, Alia Tadjer*
Nowadays, the humankind is grossly dependent on batteries in all aspects of its activities. Currently, the Li-ion batteries are doubtlessly the most widely used ones but cost and safety issues inspire the testing of other metal ions as charge carriers. Another approach is the creation of hybrid-ion batteries, but this requires the design of new electrode and electrolyte materials. Of particular interest are the processes occurring at the electrode-electrolyte interface, since they are critical for the operation of the device in terms of rate and efficiency. Quantum-mechanical modeling is a powerful tool for investigation of these processes at the molecular level. The objective of our study is to evaluate the desolvation energetics of light metal cations in the presence of electrode surface. In our models the electrode surface is the oxygen terminated (111) face of Li4Ti5O12 (LTO) – a widely studied electrode material possessing numerous advantages. The electrolytes are individual or mixed salts of Li+, Na+ and Mg2+ neutralized by PF6¯ ions in ethylene carbonate as solvent. Periodic calculations were performed with PBE/PAW method as implemented in VASP; isolated ion-solvent clusters we treated at the B3LYP/6-31G*/SMD level with Gaussian 16. Comparison is made of the desolvation behavior on the surface, in vacuum, and in implicit solvent. The results are discussed in the light of experimental findings.
The authors from CARiM’s Research Team are noted with *