Robust structural stability of flower-like δ-MnO2 as cathode for aqueous zinc ion battery

Abstract

Flower-like δ-MnO2 is in-situ grown onto carbon cloth successfully by a facile hydrothermal –method X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements are applied to identify the birnessite structure and flower-like morphology of fabricated MnO2. Due to the unique flower-like structure and constructed flake-like subunits, the electrode shows outstanding capacity of 322.92 mAh g−1 at current density of 0.3 A g−1. The ex situ XRD diffraction and galvanostatic intermittent titration technique (GITT) characterization indicate a possible energy storage mechanism of co-intercalation of H+ and Zn2+ into δ-MnO2 during the discharge process. It is considered that the distinctive morphology and layered structure can facilitate ion transportation thus making δ-MnO2 a potential cathode for aqueous zinc ion battery applications.