Nano-architectured porous Mn2O3 spheres/cubes vs rGO for asymmetric supercapacitors applications in novel solid-state electrolyte.

In this study, we have proposed a facile cost-effective hydrothermal route to synthesis homogeneously dispersed porous cubic structure Mn 2 O 3 nanospheres (230 nm) and nanocubes (250 nm) nano-architectures to fabricate an efficient energy storage device. Mesoporous Mn 2 O 3 spheres and cubes are exhibiting higher specific surface area (36.27 cm3 g−1 and 17.87 cm3g-1) and pore size (4.88 nm and 3.64 nm) respectively and in three electrode cell configuration they are showing an excellent specific capacitance of 345 F g−1 and 321 F g−1 at 0.2 A g−1, respectively. Notably, the fabricated asymmetric solid-state supercapacitor (Mn 2 O 3 nanospheres/nanocubes (positive electrode) and rGO electrodes (negative electrode)) are presenting an outstanding electrochemical performances with novel PVA-LiNO 3 gel solid-state electrolyte; ultrahigh energy density of 46 W h kg−1 at a power density of 247 W kg−1 and excellent capacitance retention of 95% after 5000 cycles are observed. Moreover, practical and operation ability of the device are successfully demonstrated by lighting up the 21 LEDs lights in series like ALU letters. Thus, the reported porous cubic Mn 2 O 3 nano-architectured electrode material synthesis strategy is more beneficial to the low cost, mass production for superior energy storage and viable alternative material for the existing commercially available materials. Image 1 • Porous Mn 2 O 3 nanospheres and nanocubes are synthesized hydrothermally. • Porous Mn 2 O 3 nanospheres show high capacitance of 345 F g−1 and long cyclic life. • Mn 2 O 3 -s//rGO ASC exhibits a high energy density of 46 W h Kg−1 at 247 WKg-1. • Mn 2 O 3 nanospheres and nanocubes ASC show 95∧% and 92% retention after 5000 cycle. [ABSTRACT FROM AUTHOR]