A low-cost portable cotton-based aluminum-air battery with high specific energy

Abstract

In this study, a novel cotton-based aluminum-air battery is demonstrated. The battery is designed to be reusable so that a sheet of aluminum foil with 0.5 mm thickness can be used for tens of times by simply replacing the cotton substrate. In addition, an inexpensive industrial-grade aluminum alloy or waste aluminum foil can be fed to the battery to reduce its operation cost. Moreover, unlike the conventional aluminum-air battery which requires complicated flow management system, the present battery only needs a small reservoir to passively supply water for the electrode reaction, leading to a greatly simplified battery structure and improved systematic energy density. With NaOH as electrolyte, the optimized battery system exhibits a peak power density of 73 mW cm-2, a specific capacity of 940 mA h g-1 and a specific energy of 930 mW h g-1. This low-cost novel battery system is expected to be applied in various portable devices, such as cell phone, electric fans and point-of-care devices.