Perspective Organic Cathode Materials for High-Energy Power Sources and Electrolyte Systems Compatible with Them

New perspective organic electrode materials based on triquinoyl derivatives for organometallic batteries with increased discharge capacities of more than 500 mA h/g are described. New electrolytes compatible with organic electrodes have been developed. It has been established that the incomplete desolvation of lithium ions during their interaction with organic electrode materials is the reason for the decrease in the electrochemical capacity in electrolytes based on carbonate solvents. The mechanism of interaction of the solvated lithium cation with organic electrode materials was studied using the example of a polymeric condensation product of triquinoyl with 1,2,4,5-tetraaminobenzene (PTTA). For comparison, the solvate shells of the lithium cation from ethylene carbonate/dimethyl carbonate (EC/DMC) and tetraglyme were chosen. Quantum-chemical modeling of the interaction of lithium cation solvate complexes with solvent molecules was compared with electrochemical data on the study of the interfaces of PTTA with liquid electrolytes: 1 M LiPF 6 solution in EC/DMC (1 : 1) and 1 M LiPF 6 solution in tetraglyme. Based on theoretical and experimental studies, it was shown that the process of lithium cation desolvation in an electrolyte based on tetraglyme makes it possible to obtain a capacity close to the theoretical one (up to 546 mA h/g), while for the EC/DMC electrolyte it is only 125 mA h/g. This decrease is due to the fact that the lithium cation adds to the functional groups of the organic material with two dimethyl carbonate molecules, and the adsorption of the PF 6 – anion occurs. And in the case of tetraglyme, the process of lithiation–delithiation of organic material occurs without the participation of the solvate shell. This fundamental result was obtained for the first time and applies to all organic electrode materials tested in carbonate solvents.