Cuprous Chloride as a New Cathode Material for Room Temperature Chloride Ion Batteries

Abstract Chloride ion batteries (CIBs) are regarded as promising energy storage devices due to their high theoretical energy density, sustainability, and abundant resources. However, the development of CIBs is still limited by the proper cathode materials and electrolyte due to the dissolution issue of active material during the electrochemical reaction. Herein, a stable room temperature rechargeable CIB coupled with CuCl cathode in a tributylmethylammonium chloride based liquid electrolyte is reported. Chloride ion shuttle behavior is evidenced in two different cells, in which lithium foil, and CuCl are used as the anode and cathode, respectively. The CuCl cathode delivers an initial discharge capacity of 278 mAh g −1 and a reversible capacity of 70 mAh g −1 is still retained after 100 cycles at a current density of 5 mA g −1 . This study indicates that CuCl would be a promising cathode for CIBs with good cycling stability.