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

AbstractWe 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 F g−1 at a current density of 1 A g−1, good rate capability of 74.6 %, and excellent capacitance retention of 89.6 % at a current density of 10 A g−1 following 5000 cycles. Based on these results, the electrode shows good potential for future supercapacitor applications.