Ultra-expanded interlayer spacing of vanadium oxide nanowires intercalated with poly(3,4-ethylene dioxythiophene) in organic ammonium ion batteries

Abstract

Rechargeable batteries employing ammonium (NH₄⁺) ions have attracted widespread interest owing to the abundant resources, eco-friendliness, and sustainability of NH₄⁺ ions. Herein, an organic–inorganic hybrid is applied to organic NH₄⁺ ion batteries. A poly (3,4-ethylene dioxythiophene) (PEDOT)-intercalated vanadium oxide nanowire (noted as VO-P-x) is applied for organic NH₄⁺ ion storage. VO-P-x with the optimal content of PEDOT showed an interlayer spacing (d-spacing) expanded to 1.82 nm, exhibiting an ultrahigh initial coulombic efficiency of 91% and a reversible capacity of 163 mA h g⁻¹. A significant improvement in NH₄⁺ ion storage was achieved due to the large interlayer spacing and conductive polymer PEDOT. Combining ex situ X-ray photoelectron spectroscopy (XPS) and multi-sweep cyclic voltammetry tests, the NH₄⁺ ion storage mechanism of VO-P-x was clearly revealed. This study provides a new strategy for designing high-performance organic ammonium batteries.