Metal organic framework-derived MnO@carbon composites for highly durable Li-ion batteries and hybrid electrochemical cells

Abstract

Exploring structurally stable and high-capacity metal oxides with carbon-based composite have attracted great attention in energy storage devices. Herein, we demonstrate gram scale synthesis of manganese oxide encapsulated carbon (MnO@C) nanofoil composite using the simple thermolysis of manganese metal organic framework (Mn-MOF) under inert atmosphere. The encapsulated MnO nanoparticles on carbon nanofoils enable higher electrochemical conductivity and extended durability as an electrode material for Li-ion batteries and supercapacitors (SCs). Specifically, the prepared MnO@C nanofoil composite delivers a reversible capacity of 1083 mAh g−1 for MnO@C, which is higher than the pristine Mn2O3 (889 mAh g−1) at a current density of 500 mA g−1 after 100 cycles. The MnO@C nanofoil composite also exhibits much better specific capacity of 771 mAh g−1 at a high current density of 2000 mA g−1 with the retention rate of 89% after 800 cycles. Furthermore, as a battery-type electrode for hybrid SCs, the MnO@C nanofoil composite shows higher capacitance and energy/power densities of 46.7 F g−1 and 15.9 Wh kg−1/4356.3 W kg−1 with excellent cycling durability. The cost-effectively synthesized MOF-derived composites could be utilized as promising materials in the development of long-term energy storage devices.