Lithium-ion batteries will play a key role in the electrification of transport,including electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs). However,the highest energy storage of Li-ion batteries and their safety issues can not meet the requirements of transportation. Therefore,developing new rechargeable batteries with higher energy density and power density as well as excellent safety and long life is greatly desired. Lithium-air batteries can provide three to five times higher energy density/specific energy than the existing battery system. In this paper,we mainly focus on the research status,existing issues and their solutions as well as perspective on lithium-air batteries. <<