Archive | 2021
Nanostructured cathodes in rechargeable batteries
Abstract
Abstract High-performance rechargeable batteries offer the best solution to resolve both energy and environmental concerns. Advanced technologies (like Li-ion batteries) govern the market of portable electronics; nonetheless, they are not suitable to be used in the environmentally friendly hybrid electric machines and large-scale energy storage systems, since they are highly expensive and afford low energy density. Therefore there are a huge demands for new batteries with higher energy densities, longer cycle lives, lower costs, and superior performances over current batteries. It has been illustrated that the fabrication of high-performance cathode is necessary to develop the high-efficient rechargeable batteries. Among rechargeable batteries, Li-ion batteries have been considered as one of the biggest specific energies. However, their intercalation mechanism can provide a theoretical specific energy of ~\xa0400\xa0Wh\xa0kg−\xa01 using both LiFePO4/graphite and LiCoO2/graphite systems. To attain higher specific energy, the use of nanotechnology to enhance the performance of cathode is mandatory. Although many efforts have been carried out to develop the high-performance anode materials (including nanostructured Si), cathode materials still exhibit relatively low charge capacities, which limit commercialization of rechargeable batteries. Current commercial cathode materials, such as metal oxides and metal phosphates, can provide intrinsically a limited capacity of 300\xa0mAh\xa0g−\xa01, which is much lower than the theoretical one for sulfur cathodes (1673\xa0mAh\xa0g−\xa01). The Li/S cell has a voltage of ~\xa02.2\xa0V vs Li/Li+ (~\xa060% of Li-ion batteries), but its theoretical specific energy is estimated at ~\xa02600\xa0Wh\xa0kg−\xa01, which is five times higher than that of the LiCoO2/graphite cell. Although sulfur shows certain advantages, like nontoxicity and low cost, the low cycle life of Li/S batteries limits significantly their commercialization. Hence, nanomaterial-based cathodes have been developed to achieve the high-performance devices/machines. This chapter focuses on various nanostructured cathodes used in rechargeable batteries. These nanostructured cathodes could be fabricated from different materials, such as metal oxides, metal sulfides, metal selenides, metal phosphates, layered double hydroxides (LDHs), and polymer nanocomposites.