Significantly improved electrical conductivity and cycling stability of manganese dioxide by poly (3,4-ethylene-dioxythiophene) coating

Manganese dioxide (MnO 2 ) is widely acknowledged as a prospective pseudocapacitive material aimed at alleviating the issue of low energy density in supercapacitors. Nevertheless, hampered by its intrinsic low conductivity and poor structural stability, MnO 2 -based energy storage materials often exhibit lower practical capacity in practical applications. During this investigation, the synthesis of MnO 2 @PEDOT (poly(3,4-ethylenedioxythiophene)) composite materials involved an in-situ oxidative polymerization approach, whereby PEDOT nanowires were integrated onto the MnO 2 nanoparticle surface. Notably, the internal configuration of the MnO 2 @PEDOT composite material demonstrated a high surface area morphology, while the externally entwined PEDOT nanowire layer further expanded the material’s specific surface area. As a result, the MnO 2 @PEDOT composite material demonstrated a specific capacitance reaching 214 F g -1 , a 91% improvement compared to unmodified MnO 2 . Furthermore, the winding of PEDOT nanowires effectively suppressed the structural disintegration of MnO 2 . The MnO 2 @PEDOT composite material exhibited a remarkable improvement in cycling stability, maintaining 81% of its initial capacity after 5000 cycles. The electron-rich PEDOT not only improved the conductivity of the inner MnO 2 through electron migration but also prevented MnO 2 structural degradation by tightly enveloping it. The outcomes of our study propose a method for constructing MnO 2 featuring a structurally stable configuration and a prolonged cycling lifespan, offering valuable insights for designing electrode materials with high cycling stability in supercapacitors.