Artificial assembly of organic-inorganic heterostructures for electrochemical energy storage at the molecular level is promising, but remains a great challenge. Here, a covalently interlayer-confined organic (polyaniline [PANI])-inorganic (MoS2 ) hybrid with a dual charge-storage mechanism is developed for boosting the reaction kinetics of supercapacitors. Systematic characterizations reveal that PANI induces a partial phase transition from the 2H to 1T phases of MoS2 , expands the interlayer spacing of MoS2 , and increases the hydrophilicity. More in-depth insights from the synchrotron radiation-based X-ray technique illustrate that the covalent grafting of PANI to MoS2 induces the formation of MoN bonds and unsaturated Mo sites, leading to increased active sites. Theoretical analysis reveals that the covalent assembly facilitates cross-layer electron transfer and decreases the diffusion barrier of K+ ions, which favors reaction kinetics. The resultant hybrid material exhibits high specific capacitance and good rate capability. This design provides an effective strategy to develop organic-inorganic heterostructures for superior K-ion storage. The K-ion storage mechanism concerning the reversible insertion/extraction upon charge/discharge is revealed through ex situ X-ray photoelectron spectroscopy.
Keywords: K-ion storage; covalently interlayer-confinement; molecular-scale assembly; nanoarchitectonics; organic-inorganic heterostructures.
© 2022 Wiley-VCH GmbH.