Recycled Nanomaterials for Energy Storage (Supercapacitor) Applications

Nowadays, humankind is in urgent need of energy generation and storage systems. The supercapacitor is one of the essential types of storage systems. The high cost of obtaining capacitor electrodes is the reason behind the researchers’ attempts to find low-cost sources. The need for the development of efficient energy storage systems is paramount in meeting the world’s future energy targets, especially when the energy costs are on the increase in addition to the escalating demand. Energy storage technologies can improve efficiencies in supply systems by storing the energy when it is in excess, and then release it timely. Batteries are slowly becoming obsolete due to their poor cyclability (limited to a few thousand) and long charge time (tens of minutes) in comparison to supercapacitors. On the other hand, supercapacitors have a long lifetime and fast charging times. Nowadays, the research focuses on advanced suitable electrode materials that directly reflect in supercapacitor technology enhancement. The researchers have prepared a variety of single components and hybrid electrodes by recycling various environmental wastes. The recycled materials include metal oxides (MnO2, Co3O4, etc.), carbon materials (carbon nanosphere, porous carbon nanoparticles, activated carbon), and hybrid materials (MnO2/graphene, CaO/AC). The obtained materials exhibited interesting structural and morphological properties as well as excellent energy storage behavior. The recycling technique provides a unique alternative cheap way for getting supercapacitor electrode materials, as well as it helps to maintain a clean environment.