High performance solid state symmetric supercapacitor based on reindeer moss-like structured Al(OH)3/MnO2/FeOOH composite electrode for energy storage applications

Abstract Developing an efficient, clean, sustainable, and reliable energy storage system is still a key challenge to resolve the growing demands of energy consumption. In this regard, supercapacitor becomes one of the foremost promising and emerging types of energy storage systems comprising properties of traditional batteries and conventional capacitors. Herein, a binder-free composite electrode of Al(OH)3/MnO2/FeOOH (AMFO) has been synthesised on stainless steel substrate via a facile, eco-friendly, and cost-effective Layer by Layer method at room temperature. The high resolution scaning electron microscopy reveals the mesoporous reindeer moss-like morphology of the synthesised electrode. The supercapacitive behaviour of the synthesised electrode has been explored in 1 M Na2SO4 electrolyte solution by using electrochemical measurement. The highest specific capacity of 2557 C g-1 has been obtained at a scan rate of 5 mV s-1, a wide potential range (-1.10 to 1.05 V). Further, a symmetric prototype supercapacitive device has been fabricated by coupling the AMFO electrodes. The high specific capacitance of 511 F g-1 has been obtained with ultra-high energy and power densities of ∼443 Wh kg-1 and ∼13 kW kg-1, respectively. These results indicate that this electrode has potential practical applications as a power backup, portable electronic device, and energy storage system.