Polypyrrole as a Novel Chloride-Storage Electrode for Seawater Desalination

The desalination battery is regarded as a promising high-efficiency technology for seawater desalination on account of the reversible salt-ion storage in the bulk of the battery electrodes. Herein, polypyrrole is used as a new electrode to store chloride ions in seawater desalination. The as-prepared polypyrrole composite electrode shows good electrochemical reversibility in chloride-ion storage and removal in the aqueous NaCl electrolyte. When this chloride electrode is incorporated with a sodium electrode of sodium manganese oxide, a desalination battery that can capture chloride and sodium ions from the electrolyte through the electrochemical redox reactions is obtained. A stable and reversible capacity of 40 mAh g⁻¹ of the desalination battery is achieved after 200 cycles.