Ab initio Molecular Dynamics Investigations of the Speciation and Reactivity of Deep Eutectic Electrolytes in Aluminum Batteries

Deep eutectic solvents (DESs) have emerged as an alternative for conventional ionic liquids in aluminum batteries. Elucidating DESs composition is fundamental to understand electrodeposition the battery anode. Despite numerous experimental efforts, speciation of these remains elusive. This work shows how ab initio molecular dynamics (AIMD) simulations can shed light on DESs. For particular example AlCl3:urea, one most popular DESs, we carried out a systematic AIMD study, showing excess AlCl3 AlCl3:urea mixture promotes stability species vs neutral ones and also favors reactivity system. These two facts explain experimentally observed enhanced electrochemical activity salt-rich We observe transfer simple [AlClx(urea)y] clusters between different liquid, giving rise free [AlCl4]− units. The small size units transport towards anode, facilitating aluminum.