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.