An aqueous rechargeable chloride ion battery

In recent years, the increasing demand for energy has spurred the development of novel and effective energy storage technologies which are safe and reliable. Herein, we introduce an aqueous rechargeable battery comprising of a bismuth oxychloride (BiOCl) anode and a silver cathode in an aqueous NaCl electrolyte solution. This innovative way of energy storage is based on a redox reaction involving the shuttling of chloride ions between the two electrodes. During the charging process, chloride ions are released from the anode and intercalated into the cathode whereas discharging causes the extraction of chloride ions from the cathode and the recovery of BiOCl at anode side. This new battery system can deliver a stable and reversible capacity of 92.1 mAh g(-1) when operated at a current density 400 mA g(-1). Further investigations involving the reaction mechanisms are given by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). This aqueous chloride ion battery is the first of its kind and we believe it will contribute greatly towards future battery technologies.