MXene‐Boosted Imine Cathodes with Extended Conjugated Structure for Aqueous Zinc‐Ion Batteries

Organic molecules have been considered promising energy‐storage materials in aqueous zinc‐ion batteries (ZIBs), but are plagued by poor conductivity and structural instability because of the short‐range conjugated structure and low molecular weight. Herein, an imine‐based tris(aza)pentacene (TAP) with extended conjugated effects along the CN backbones is proposed, which is in situ injected into layered MXene to form a TAP/Ti 3 C 2 T x cathode. Theoretical and electrochemical analyses reveal a selective H + /Zn 2+ co‐insertion/extraction mechanism in TAP, which is ascribed to the steric effect on the availability of active CN sites. Moreover, Ti 3 C 2 T x , as a conductive scaffold, favors fast Zn 2+ diffusion to boost the electrode kinetics of TAP. Close electronic interactions between TAP and Ti 3 C 2 T x preserve the structural integrity of TAP/Ti 3 C 2 T x during the repeated charge/discharge. Accordingly, the TAP/Ti 3 C 2 T x cathode delivers a high reversible capacity of 303 mAh g −1 at 0.04 A g −1 in aqueous ZIBs, which also realizes an ultralong lifetime over 10 000 cycles with a capacity retention of 81.6%. Furthermore, flexible Zn||TAP/Ti 3 C 2 T x batteries with a quasi‐solid‐state electrolyte demonstrate potential application in wearable electronic devices. This work offers pivotal guidance to create highly stable organic electrodes for advanced ZIBs.