MANGANESE OXIDE BASE ELECTRODE MATERIALS WITH POROUS STRUCTURES FOR SUPERCAPACITOR

MnO2-based materials with porous structures comprising nanorodes or nanowires and nanoparticles were synthesized via a facilely chemical precipitation method. Diverse manganese sources and doping amounts of cobalt and chromium ions were designed to gain MnO2-based electrode materials with remarkable electrochemical performances. Pure MnO2 prepared by MnAc2 exhibited a superior specific capacitance of 97.34 F g(-1) at the current density of 200 mA g(-1). MnO2-based materials with cobalt adulteration at a Co/Mn molar ratio of 1:50 (MnO2-Co-50-1) revealed a specific capacitance of 116.6 F g(-1) at the current density of 200 mA g(-1). While MnO2-based materials with chromium adulteration at a Cr/Mn molar ratio of 1:20 (MnO2-Cr-20-1) showed up a higher specific capacitance of 144.26 F g(-1) at the current density of 200 mA g-1. It is worth mentioning that all electrochemical tests were measured with a wide voltage region of 0-1V in a neutral electrolyte of 1M Na2SO4 aqueous solution. Even so materials still showed up an excellent cycling stability, and MnO2-Co-50-1 retained 101.69% of capacitance (58.02 F g(-1)) at a scan rate of 100 mV s(-1) after 2500 cycles while MnO2-Cr-20-1 retained 86% of capacitance (72.83 F g(-1)) at a scan rate of 100 mV s(-1) after 2500 cycles. All these profited greatly from materials' ideally porous network structures, which offers an efficient structural platform for fast energy storage.