Integrating multiple redox-active sites and universal electrode-active features into covalent triazine frameworks for organic alkali metal-ion batteries

Abstract

The advantages of redox-active polymers with multiple redox-active sites and multiple functions stem from the controllability of organic synthesis, which makes it possible to construct universal organic alkali metal-ion batteries. Herein, triazine-bridged hexaazatrinaphthylene polymer (HATN-CTF) was synthesized and then first served as both cathode and anode materials for lithium organic batteries. Interestingly, we realized the controllable construction of crystalline and amorphous HATN-CTF (cHATN-CTF and aHATN-CTF) and give a systematic study to show the superiority of aHATN-CTF resulted from the more abundant active sites and shortened ion diffusion paths. Most importantly, the integration of hexaazatrinaphthylene core and peripheral triazine moieties endows aHATN-CTF with abundant active centers (CN and CC groups), the ability to absorb cations and anions and universal electrode-active features at high/low potential (cathode/anode side), which have been confirmed by the electrochemical analysis, characterizations and theoretical calculations. Furthermore, aHATN-CTF also shows potential applications in all-organic symmetric batteries (AOBs), flexible AOBs (FAOBs) and other rechargeable alkali metal-ion batteries. Our findings highlight the importance of redox-active polymers with multiple redox-active sites and multiple electrode-active features and open a new avenue to construct organic alkali metal-ion batteries.