Manganese oxide nanorods decorated table sugar derived carbon as efficient bifunctional catalyst in rechargeable Zn-air batteries

Abstract

Despite its commercial success as a primary battery, Zn-air battery is struggling to sustain a reasonable cycling performance mainly because of the lack of robust bifunctional electrocatalysts which smoothen the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) taking place on its air-cathode. Composites of carbon/manganese oxide have emerged as a potential solution with high catalytic performance; however, the use of non-renewable carbon sources with tedious and non-scalable synthetic methods notably compromised the merit of being low cost. In this work, high quantity of carbon is produced from renewable source of readily available table sugar by a facile room temperature dehydration process, on which manganese oxide nanorods are grown to yield an electrocatalyst of MnOx@AC-S with high oxygen bifunctional catalytic activities. A Zn-air battery with the MnOx@AC-S composite catalyst in its air-cathode delivers a peak power density of 116 mW cm?2 and relatively stable cycling performance over 215 discharge and charge cycles. With decent performance and high synthetic yield achieved for the MnOx@AC-S catalyst form a renewable source, this research sheds light on the advancement of low-cost yet efficient electrocatalyst for the industrialization of rechargeable Zn-air battery. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.