A high-capacity polyaniline-intercalated layered vanadium oxide for aqueous ammonium-ion batteries.

A 1.55 nm-interlayer spacing-expanded polyaniline-intercalated vanadium oxide, as a new electrode material for NH4+-ion batteries, exhibits the highest ever reported capacity of ∼307 mA h g-1 at a current density of 0.5 A g-1. In situ FT-IR and XPS studies confirm the reversible NH4+ storage is accompanied by H bond formation/breaking within the functional group of -VO···H.