Investigation of Al(TfO)-based deep eutectic solvent electrolytes for aluminium-ion batteries. Part I: understanding the positively charged Al complex formation.

Aluminium-ion batteries (AIB) are very attractive energy storage systems due to the high availability and theoretical energy density of metallic aluminium. However, the practical performance of AIBs in AlCl-based electrolytes is limited by the low reversible capacity of the positive graphite electrode for large AlCl anions. Moreover, the use of high energy oxide-based electrodes such as MnO requires the presence of positively charged aluminium complexes in the electrolyte.