Solvent Effect on the Stability of Coordination Polymers as Electrode Materials for Li-Ion Batteries
Yanislav Danchovski
Abstract: The implementation of coordination polymers has proven to be a successful strategy for improvement of electrochemical properties of the electrode materials for Li-ion batteries. [1] Quinone polymers of Ni show relatively high redox potentials and remarkable capacity for storage of Li-ions. This is due to the existence of multiple redox centres – both the metal ion and the quinone ligand are involved in the redox reactions. Major problem for the battery lifecycle is the graduate dissolution of the electrodes. The objective of the current study is to examine the structural stability in the presence of electrolyte, specifically of the standard solvent – ethylene carbonate.
Several polymers of quinone-based ligands and nickel in two oxidation states (II, IV) are modelled utilizing the PBE/PAW method in periodic boundary conditions, and the electrode potential is recalculated accounting for the electrode-solvent interaction. The solvent is simulated by different approaches – implicit, explicit, and hybrid. The calculations were carried out with the VASP code. The presence of explicit solvent molecules sheds most abundant light on the structural and electrochemical changes occurring in the material. The obtained results expectedly show a slight decrease in the potential. However, the ligands remain coordinated and the structural stability of the polymer is sustained. This is an evidence that the quinone-based coordination polymers would be robust electrode materials.
References:
1. Danchovski, Y.; Rasheev, H.; Stoyanova, R.; Tadjer, A. Molecules, 27, 6805, (2022)
VIHREN-CARiM 2019 