High specific capacitance of a 3D-metal–organic framework-confined growth in CoMn2O4 nanostars as advanced supercapacitor electrode materials

Abstract

In the presence of fossil fuels, several environmental concerns, such as energy shortage, environmental pollution, and global warming may occur in the present century. In this respect, supercapacitors have been introduced as green energy storage systems playing a central role in providing a sustainable human society. In this work, an advanced strategy was initially demonstrated through various synergistic effects to synthesize cobalt(II) metal–organic framework#CoMn₂O₄ nanocomposites (Co(II)-TMU-63#CoMn₂O₄ NCPs) having interfaces adapted at tunable chemical nanocomposites for hybrid supercapacitors. The given NCPs showed excellent electrochemical performance at 7 A g⁻¹ current density endowed with a specific capacity of 156 mA h g⁻¹ (1420 F g⁻¹) and good cycling stability at 10 A g⁻¹ current density, following 7000 cycles with 93.3% capacity retention. The hybrid supercapacitor was assembled using activated carbon (AC) as negative and NCPs as positive electrodes, which delivered specific energy of 38.54 W h kg⁻¹ and maximum-specific power of 2312.4 W kg⁻¹ with 89.5% capacity retention over 7000 cycles. The enhanced electrochemical performances of Co(II)-TMU-63#CoMn₂O₄ NCPs can be attributed to the high surface area, porous structure, open metal sites functioning as electron collectors to enhance electron transfer as well as unique morphology and synergistic effect between Co(II)-TMU-63 and CoMn₂O₄. This work may inspire a new development of interface-adapted nanocomposite for advanced energy storage applications.