Facile synthesis of TiO1.77(OH)0.46·0.2 H2O and TiO2 and their applications for aqueous ammonium-ion battery

Rechargeable aqueous ammonium-ion batteries (AAIBs) have attracted more and more attention in energy storage devices because of great safety and cost-effectiveness, as well as excellent rate capability. Recently, it is the main exploration focus for the further improvement of AAIBs to develop suitable electrode materials. Herein, titanic acid and TiO 2 were simply synthesized by the facile co-precipitation approach. Titanic acid showed higher capacity of 104.5 mAh g −1 at the 0.1 A g −1 current density, and higher cyclability with the 91.2% capacity retention cycled 1000 cycles at 1 A g −1 . Titanic acid is promising as aqueous ammonium-ion batteries with great stability and capacity.