Investigation the role of α-MnO۲/graphene q-dot as a novel cathode material for Li-O۲ batteries

By increasing the demand for more efficient energy storage systems, especially with the development of electric transportation industry, new generation batteries have come into operation. Meanwhile, lithium-air batteries are considered as attractive candidates for the next generation of lithium batteries due to their high energy density (>۱۱۰۰۰ Wh.kg-۱) which is comparable to gasoline (۱۳۰۰۰ Wh.kg-۱). On the other hand, these batteries face with some challenges such as formation of lithium peroxide (Li۲O۲) and lithium oxide (Li۲O) which can limit the transfer of electrons. Thus, utilization of metal catalysts is the best way to ameliorate the reversibility of these batteries. Inspired by this concept, the method of manufacturing and preparation of manganese dioxide catalyst with graphene quantum dot is introduced. In conclusion, based on different charge/discharge processes, at a current density of ۱۰۰ mA/g, ۱۲۰۰۰ mAh/g obtained for α-MnO۲. Furthermore, with increasing the current density up to ۲۰۰ mA/g, ۳۴۰۰ mAh/g and ۱۱۲۵۰ mAh/g obtained for α-MnO۲ and α-MnO۲/graphene quantum dot, respectively. Moreover, EIS result depicted that this structure can provide sufficient channels for Li insertion/extraction processes. Eventually, IR, FESEM, and XRD results demonstrated uniform structure of electrode material.

Keywords:

Li-O۲ battery , Metal oxide catalyst , Li-O۲ , α-MnO۲ , graphene quantum dot