Technologies for extending zinc–air battery’s cyclelife: A review

Zinc–air batteries are devices which convert chemical energy into electrical energy and vice versa during charge/discharge. Zinc–air battery has been used for a long time due to its high energy density, great availability and low-level pollution, and zinc–air primary battery has already commercialized in hearing aids, navigation lights, and railway signals so forth; while the problem of cyclelife limits rechargeable zinc–air battery applied to the fields of transportation and energy storage. To thoroughly understand the nature of electrically rechargeable zinc–air battery, we have made detailed failure mechanism investigations of zinc electrode, air electrode, electrolyte, and separator; meanwhile research progress of a rechargeable zinc–air battery respectively based on bifunctional air electrode and triple electrodes described in this work have been analyzed in comparison. Furthermore, working conditions including air system, electrolyte system and charge–discharge modes influencing zinc–air battery’s cyclelife have been discussed as well. The corresponding solutions are also provided for extending cyclelife of the battery, such as horizontal configuration, flowing electrolyte, pulsating currents, corrosion inhibitors, triple electrodes and so on. These causes and measures will help improve the cyclelife and performance of zinc–air batteries, and thus offer an alternative to energy storage and transportation.