ABSTRACT
The rechargeable lithium-air (Li-O2) battery has been attracting a great amount of consideration in recent years since the first report on the feasibility of this system using a nonaqueous polymeric electrolyte membrane by Abraham and Jiang [1]. Li-O2 batteries, which use a different chemistry from intercalating lithium-ion batteries (LIBs), have a phenomenal theoretical specific energy of 5200 Wh kg−1 (based on the mass of lithium metal and gained oxygen during discharge). This specific energy, which is high enough to compete with that of gasoline (13,000 Wh kg−1), motivates the investigation of Li-O2 batteries for potential applications in electrical vehicles (EVs). Besides, relatively low conversion efficiency of the present internal combustion engines (less than 13%) limits the practical specific energy of gasoline to values as low as 1700 Wh kg−1 [2]. Considering the 90% conversion efficiency of electrical engines of EVs, Li-O2 battery system needs to deliver around 33% of its theoretical specific energy to have the same practical specific energy as gasoline, which is not
inconceivable. Various challenges facing the development of Li-O2 battery system and corresponding solutions introduced from the materials point of view are summarized in the present context.
