Building ultra-stable and low-temperature aqueous zinc–organic batteries via noncovalent supramolecular self-assembly strategy

Abstract

Zinc-organic batteries (ZOB) have garnered significant attention owing to their design flexibility and abundant raw materials. However, a notable drawback arises from the tendency of organic electrodes to dissolve in the electrolyte during cycling, resulting in diminished cycle stability and a shortened lifespan. Herein, we propose a noncovalent supramolecular self-assembly approach to address the challenge of organic electrode dissolution, namely the hydrogen-bonded organic polymer (HOP) is introduced as the cathode ensuring the electrolyte/electrode stability in ZOB. The HOP comprises perylene anhydride units characterized by robust strong π-π stacking and hydrogen bond connections. This configuration enables the reversible storage of Zn2+/H3O+ through CO/CO bond conversion, as validated by in-situ ATR-FTIR and ex-situ XPS analyses. Employing a 1 m Zn(OTF)2 electrolyte, the Zn//HOP cell exhibited stable cycling at room temperature for 20,000 cycles with nearly 80 % capacity retention and operated at –5 °C for 300 cycles with 100 % capacity retention. Our findings explore the noncovalent supramolecular self-assembly strategy in producing organic electrodes resistant to dissolution.