Intercalation and electrochemical behaviors of layered FeOCl cathode material in chloride ion battery

Layered metal oxychloride FeOCl is considered as one of the promising cathode materials for chloride ion batteries due to its abundant elemental components and high capacity. Herein, we report the intercalation and electrochemical behaviors of the layered FeOCl material in the chloride ion battery. The intercalation of N-methyl-2-pyrrolidinone into the FeOCl layers has been found during the drying of the electrode coating at 373 K. The electrolyte component can also be intercalated into the FeOCl layers at 298 K without charge and discharge. The intercalation by these organic components results in evident expansion of the layers. Repeated charge and discharge cycling contributes to an activation of the FeOCl electrode and thus an increase of the discharge capacity. The results of elemental analysis and Fourier transform infrared spectroscopy confirm the chloride ion transfer of the FeOCl electrode during cycling.