Strategies for design and modification of electrode materials in novel aqueous ammonium ion battery

Aqueous ammonium ion battery, as a new candidate aqueous energy storage system, attracts much attention on account of the unique characteristics including lightest molar mass and the smallest hydrated ionic size of ammonium ion as charge carriers. In the assembled aqueous system, the hydrated vanadium oxide of (NH4)2V6O16∙1.5 H2O (NHVOw) with nanorod morphology as cathode is successfully synthesized and further modified by loading carbon on the surface to obtain the composite (NH4)2V6O16∙1.5 H2O/Carbon (NHVOw/C), which exhibits more excellent electrochemical performance due to the enlarged layered structure and high conductivity from carbon material. Meanwhile, the 1,4,5,8-naphthalenetetracarboxylic dianhydride-derived polyimide abbreviated as PNTCDA with multiple carbonyl groups as anode is synthesized and exhibits outstanding rate capability. Finally, this aqueous ammonium ion full battery is firstly assembled by NHVOw/C as cathode and PNTCDA as anode in NH4Cl electrolyte, which fully demonstrates the feasibility of ammonium ion energy storage and provides a new idea for aqueous battery systems.