Interfacial Electric Field Enhanced Free‐Standing VO2/rGO Aerogel Anode with Ultra High Mass Energy Density for Aqueous Ammonium Ion Battery

Abstract Aqueous batteries have become a promising means of energy storage due to its environmental friendliness. Nevertheless, it often exhibits limited energy density that hinder their application. Considering that ammonium ion (NH 4 + ) has a low mass and a small hydration radius, aqueous ammonium ion batteries (AAIBs) are expected to solve the problem of low energy density. Herein, we obtain Vanadium dioxide/reduced graphene oxide aerogel (VOGA) by in‐situ growth of VO 2 on the graphene surface for interfacial electric field enhanced AAIBs to achieve high mass energy density. The VOGA free‐standing electrode achieves a specific capacity of up to 655 mA g −1 at a current density of 0.5 A g −1 . And the mass energy density of the VOGA.