Hydrangea-like Mesoporous Carbon Architectures Embedded with MnOx Nanoparticles for Solid-State Asymmetric Supercapacitors with Enhanced Areal Capacitance

Hydrangea-like mesoporous carbon architectures embedded with MnOx nanoparticles (MnOx@C) are synthesized via the pyrolysis of Mn-MOFs (Mn-based metal organic frameworks) grwon on nickel foam as a binder-free electrode for asymmetric supercapacitors. The as-prepared MnOx@C featuring stacked carbon flakes with mesoporous structure and embedded with nanosized MnOx particles exhibit superior electrochemical performances with a specific areal capacitance of 1518 mF cm(-2) at a current density of 3 mA cm(-2). An asymmetric supercapacitor that is fabricated using MnOx@C as cathode and activated carbon as anode demonstrates remarkable areal power density of 12.2 W cm(-2), areal energy density of 169.4 mWh cm(-2) and excellent rate capability. This work provides a facile and effective strategy to construct MnOx@C supercapacitive materials so as to efficiently enhance electron transport at the meantime achieve rapid ion diffusion.