Microwave-assisted self-template synthesis of mesoporous anatase TiO2 spheres for non-aqueous Al-ion batteries: Textural property optimization and enhanced reversible Al3+ storage

Mesoporous anatase TiO2 spheres (MATS) are elaborated via microwave-assisted rapid crystallization of hydrous colloidal (HTCS) self-template. Tuning the hydrothermal and calcination temperatures allow for textural property-controllable synthesis. The optimal MATS demonstrated as a promising cathode material aluminium-ion batteries (AIBs) show superior rate capacity performances. Their large surface area porous structure offer robust interconnected scaffold Al3+ insertion/exertion with higher reversibility. constructed non-aqueous AIBs RTILs electrolyte deliver highest initial 145.3 mA h g?1 at 0.2C high Coulombic efficiency ? 96.5%, reversible 78.0 1C can be retained after 200 cycles 98.6%. Our study on Al storage mechanism further shows charge/discharge process involves extraction/insertion species (Al3+, AlCl4?, Al2Cl7?, etc.) into crystal lattices formation intermediate aluminium titanium oxides (Al2Ti7O15 Al2TiO5) non-oxides (Ti(AlCl4)2 Ti(ClO4)4). continuous enrichment latter during cycling greatly deteriorates reversibility AIBs.