Carbonyl and imine conjugated frameworks for aqueous Organo-Aluminum batteries with high specific capacity and low...

Carbonyl or imine-based compounds have received a great deal of attention due to their high specific capacity and designability as cathodes for aqueous rechargeable organo-aluminum batteries. However, the inherent low conductivity and high solubility of carbonyl and imine-based compounds severely affect the cycling stability of aluminum batteries. Therefore, it is urgent to find an organic cathodes material with low solubility and good cycling performance. In this work, dibenzo[a,c]dibenzo[5,6:7,8]quinoxalino[2,3-i]phenazine-10,21-dione (DDQP) were synthesized by simple dehydration condensation to form new imine covalent bonds, which led to the synthesis of imine-conjugated backbone structures with carbonyl, extended π-conjugation planes, and increased active sites, resulting in increased specific capacities. Its storage mechanism with Al(OTF)₂⁺ has also been confirmed. This monovalent ion usually possesses a lower coulombic interaction, which leads to a reduced solubility of DDQP during redox processes and improves its cyclic stability. The specific capacity of DDQP is 252.22 mAh/g at a current density of 400 mA g^-1. After cycling, the discharge specific capacity remains at 219 mAh/g. Surprisingly, the conductivity of the battery also is improved by this structure of multiple active sites. And it can be further confirmed by theoretical calculations that the synthesis of DDQP realigns the arrangement of the electron cloud, enhances the electron affinity, and reduces the energy gap. This study provides a new reference for improving the performance of aqueous organic aluminum batteries.