NiMn2O4 Nanosheet-Decorated Hierarchically Porous Polyaromatic Carbon Spheres for High-Performance Supercapacitors

We have designed and synthesized hierarchically porous and spherical carbons decorated with a nickel manganese oxide (NiMn2O4) and utilized them as a pseudocapacitor electrode. The polyanthracene (PAT)-based carbon materials were firstly synthesized by the self-polymerization of bromomethylated anthracene in the presence of zinc bromide as a catalyst and bromomethyl methyl ether as a crosslinker. The carbon materials with a 3D network were fabricated by direct carbonization and activation of the as-prepared PAT. The micro-, meso-, and macroporous 3D carbon materials are characterized by a large specific surface area, an electrolyte-electrode interface area, and a continuous electron transport path. To produce high-performance pseudocapacitor electrodes, NiMn2O4-decorated carbon hybrid materials (C@NiMn2O4) have also been synthesized by using a hydrothermal method. The C@NiMn2O4 composites exhibit a maximum specific capacitance of 470.7 Fg(-1) at a current density of 1 Ag-1, good rate capability of 74.6 %, and excellent capacitance retention of 89.6% at a current density of 10 Ag-1 following 5000 cycles. Based on these results, the electrode shows good potential for future supercapacitor applications.