Highly efficient phthalocyanine based aqueous Zn-ion flexible-batteries

Aqueous Zn-ion battery has developed as an alternative to overcome the limitations of conventional Li-ion batteries, but its application is insufficient due to low reversibility and electrochemical reliability. In this study, we developed a cathode for aqueous Zn-ion battery with improvement of reversibility and electrochemical reliability utilizing phthalocyanine (PTC) that efficiently transports metal ions and electrons. The intercalation/de-intercalation reaction of Zn2+ ions changes according to the central metal ligand ion of PTC, and iron (II) coordinated PTC exhibited the outstanding energy storage capacity (161.34 mAh/g) and electrochemical reliability (99%, 100 cycles). Based on maximized electrochemical performance and reliability, Zn-ion flexible battery was successfully demonstrated by utilizing air-spray coating.