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/Ti3C2Tx cathode. Theoretical and electrochemical analyses reveal a selective H+/Zn2+ co‐insertion/extraction mechanism in TAP, which is ascribed to the steric effect on the availability of active CN sites. Moreover, Ti3C2Tx, as a conductive scaffold, favors fast Zn2+ diffusion to boost the electrode kinetics of TAP. Close electronic interactions between TAP and Ti3C2Tx preserve the structural integrity of TAP/Ti3C2Tx during the repeated charge/discharge. Accordingly, the TAP/Ti3C2Tx 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/Ti3C2Tx 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. Aqueous zinc‐ion batteries (ZIBs) have been the spotlight in energy storage owing to their intrinsic safety, fast kinetics, and low cost. In this work, an imine‐based tris(aza)pentacene (TAP) with extended conjugated structure is in situ injected into layered Ti‐based MXene (Ti3C2Tx) to form a TAP/Ti3C2Tx cathode. The assembled ZIBs exhibit ultralong cycle stability and display impressive potential for electronic devices.