Enhancing Electrochemical and Mechanical Robustness of MoS ₂ -Based Flexible Supercapacitors via In Situ Tunable Electro-Polymerization of Polypyrrole Coating

Molybdenum disulfide (MoS2) nanosheets are promising flexible supercapacitor electrode materials due to their inherent flexibility derived from a unique two-dimensional layered crystal structure. However, challenges including low conductivity and poor mechanical stability remain to be solved. In this study, an ultrathin polypyrrole (PPy) layer was fabricated on the surface of 1T/2H MoS2 nanosheets via electrochemical deposition through scan cyclic voltammetry. Due to the excellent conductivity, pseudocapacitance, and flexibility of PPy, the prepared 1T/2H MoS2@PPy composite electrode exhibits enhanced capacitance performance and cycling stability. It achieves a maximum areal capacitance that can reach 912.8 mF cm–2 at a current density of 1 mA cm–2 and maintains 84% capacity after 3000 cycles. Crucially, the flexible supercapacitor possesses an excellent specific capacitance of 333 mF cm–2 and superior mechanical robustness with achieving ∼100% capacity retention after 5000 bending cycles, highlighting its high potential for flexible wearable electronics.