Mechanistic Investigation of Intercalation Process in Two Specific Aqueous and Non-aqueous Aluminum Ion Batteries

摘要

In this thesis, the intercalation mechanism in two specific aluminum ion batteries (AIBs), aqueous and non-aqueous, are investigated. The first thrust is focused on the charge storage mechanism of α-MnO2 with high theoretical capacity in 2 m Al(OTF)3 aqueous electrolyte. In this study, we find that the reversible capacity is contributed by the insertion of hydronium ion, which compromises the achievable cell-level energy density of the aqueous AIB. To truly utilize the high-capacity Al metal anode, the focus is put on a non-aqueous AIB system in the second thrust. We investigate the underlying charge storage mechanism of an organic cathode made of benzo[1,2-b:4,5-b′]dithiophene-4,8-dione (BDTD) in an ionic liquid electrolyte (AlCl3/trimethylamine hydrochloride (TMAHCl) = 1.8 by mole), and AlCl2+ is identified as the charge carrier ion. Understanding the intercalation mechanism is critical in terms of assessing the practical cell-level achievable energy density and scalability of the developed AIB technologies.