Establishing Hybrid Electrode Frameworks via Hierarchical Integration of MOFs and Conducting Polymers for...

Herein, a hierarchical hybrid electrode consisting of multidimensional PANI: PSS/Fe-BTC/carbon fiber cloth (mPFC) is fabricated via the in situ growth of 2D BTC metal-organic framework (MOF) nanosheets on Fe-electrodeposited carbon cloth and subsequent polymerization of PANI: PSS. The resulting architecture provides a mechanically robust electrode framework in which multiscale structural domains are seamlessly integrated. Such structural integration ensures strong interfacial coupling, continuous ion/electron transport pathways, and accelerated charge-transfer kinetics. In particular, the incorporation of PANI: PSS introduces a dual redox-active structure, thereby maximizing the exposure of electrochemically active sites throughout the electrode. As a result, the mPFC electrode delivers a high reversible capacity of 415 mA h g^-1 at 0.1 A g^-1 and retains 92.2% of its capacity after 3000 cycles at 2.0 A g^-1, along with an energy density of 275.2 W h kg^-1 and a peak power density of 91.7 kW kg^-1. Experimental results accompanied by theoretical calculations verify that Fe-BTC and PANI: PSS function as redox-active sites for the storage of Li cations and PF₆ anions, respectively, and that the low diffusion energy barrier (≈0.059 eV) enables the consecutive faradaic reactions of the mPFC electrode within a wide potential window of 2.0-4.5 V.