Interlayer and Phase Engineering Modifications of K‐MoS2@C Nanoflowers for High‐Performance Degradable Zn‐Ion Batteries

Abstract 2D transition metal dichalcogenides (TMDs) have garnered significant interest as cathode materials for aqueous zinc‐ion batteries (AZIBs) due to their open transport channels and abundant Zn 2+ intercalation sites. However, unmodified TMDs exhibit low electrochemical activity and poor kinetics owing to the high binding energy and large hydration radius of divalent Zn 2+ . To overcome these limitations, an interlayer engineering strategy is proposed where K + is preintercalated into K‐MoS 2 nanosheets, which then undergo in situ growth on carbon nanospheres (denoted as K‐MoS 2 @C nanoflowers). This strategy stimulates in‐plane redox‐active sites, expands the interlayer spacing (from 6.16 to 9.42 Å), and induces the formation of abundant MoS 2 1T‐phase. The K‐MoS 2 @C cathode demonstrates excellent redox activity and fast kinetics, attributed to the potassium ions acting as a structural “stabilizer” and an electrostatic interaction “shield,” accelerating charge transfer, promoting Zn 2+ diffusion, and ensuring structural stability. Meanwhile, the carbon nanospheres serve as a 3D conductive network for Zn 2+ and enhance the cathode's hydrophilicity. More significantly, the outstanding electrochemical performance of K‐MoS 2 @C, along with its superior biocompatibility and degradability of its related components, can enable an implantable energy supply, providing novel opportunities for the application of transient electronics.