An In Situ Oxidative Polymerization Method to Synthesize Mesoporous Polypyrrole/MnO₂ Composites for Supercapacitors

Manganese dioxide (MnO₂) shows great potential in the field of electrochemical performance. But its poor conductivity, easy dissolution in electrolytes and undesirable ionic accessibility hinder its application. The construction of mesoporous polypyrrole/manganese dioxide (PPy/MnO₂) composites can effectively alleviate these problems. Herein, an in situ oxidative polymerization method is developed to synthesize mesoporous PPy/MnO₂ composites. In this method, Pluronic P123 and pyrrole monomers are co-assembled on the surface of MnO₂. MnO₂ is used as an oxidation initiator to polymerize pyrrole under acidic conditions and as a substrate for a uniform coating of PPy. The obtained composites, with a large electrochemical effective area, more reaction sites and good structural stability have better capacitor performance (182.8 F g^-1), higher than MnO₂ (116.6 F g^-1) at the same current density. This method provides a meaningful reference for the development of mesoporous PPy/MnO₂ supercapacitor materials.