Realizing high-performance of quinone-based cathode via multiple active centers for aqueous zinc ion batteries

Aqueous zinc ion batteries (AZIBs) have received widespread consideration owing to non-toxicity, proper capacity, and abundant reserves. Among numerous cathode materials , organics with adjustable structures are prospective campaigners. Naphtha [2, 3-h] naphtha [2', 3': 7, 8] quinoxalino [2, 3-a] naphtha [2', 3': 7, 8] quinoxalino [2, 3-c] phenazine-5, 10, 15, 20, 25, 30-hexaone (AQPH) with large conjugated structure is synthesized through convenient condensation reaction . As an organic cathode of AZIBs, multiple active sites endow AQPH with a decent capacity (297.7 mAh g −1 under 0.05 A g −1 ) and a brilliant cycling life (over 10,000 cycles under 10 A g −1 ). Simultaneously, large conjugated structure supplies AQPH with a rapid electron transfer rate, inducing a high Zn 2+ diffusion coefficient (3.3 × 10 −10 ∼2.6 × 10 −8  cm 2  s −1 ) and an outstanding rate ability (96.7 mAh g −1 under 20 A g −1 ). Furthermore, theoretical calculations and ex-situ characterizations prove that C O and C N are the active sites of Zn 2+ storage. This work demonstrates that expanded conjugated structure and increased active centers of organic molecules are beneficial for accomplishing sustainable high-performance AZIBs.