Presentation by Yanislav Danchovski
MOLECULAR MODELING OF METAL COMPLEXES WITH QUINONE-based LIGANDS FOR Li-ION STORAGE
Yanislav Danchovski*, Hristo Rasheev*, Radostina Stoyanova*, Alia Tadjer*
Traditionally, the electrodes in commercial Li-ion batteries are of inorganic origin containing mainly oxides of transition metals but the application of organic materials as electrodes for Li-ion batteries has recently been extensively investigated due to numerous advantages and opportunities for performance improvement they allow. Among the advantages are: ease of synthesis, tunable structure, low weight, computationally simple, properties predictivity, etc. Combination of transition metals with organic components could potentially exhibit even better efficiency – both the metal ion and the ligands would be electrochemically active and this increases the number of redox centers.
The current study focuses on estimating the electrochemical potential of Ni and V complexes with benzoquinone-based ligand in the reaction of reduction with Li. Models of complexes with two ligands are built in two oxidation states of the metal ion: Ni(II) and Ni(IV), as well as V(III) and V(V). The calculations are made using DFT and the potential of step-by-step insertion of lithium atoms is estimated using the free energy changes after structure relaxation. Each stage of the reduction is thoroughly examined and documented. Both Ni and V complexes show potential for significant Li intercalation retaining structural stability. The values of electrode potentials of the different stages of reduction imply possible applications of these complexes as novel electrode materials. The strategy of combining two types of redox-active components could be used for future design of promising innovative materials for energy storage and conversion.
The authors from CARiM’s Research Team are noted with *