REVIEW 781 wileyonlinelibrary.com www.MaterialsViews.com www.advenergymat.dean electrochemical reaction; [ 30 ] importance of nano-structured materials and their utilization for Li-air batteries is emphasized; [ 33 ] issues of aqueous vs. nonaqueous electrolytes (solubility and diffusivity of oxygen) are addressed; [ 34 ] today's challenges of Li-air batteries are rooted in material discovery and optimization. [ 36 ] One of the most valuable insights gained from these review articles is that the signifi cant challenge is the lack of fundamental understanding on each Li-air cell component, as well as on the whole system performing together as an electrochemical device. The reason for this lack of understanding partly comes from the fact that the amount of research effort on Li-air cells is relatively small compared to that on the other mainstream batteries, i.e., Li-ion cells. This could also explain why, at the current stage, it is diffi cult to construct reproducible and reliable Li-air cells, which is the basis for the commercialization of Li-air cells in the foreseeable future. Note that the operating mechanism of Li-air cells is inherently different from that of Li-ion batteries, which are based on an intercalation/ deintercalation reaction; Li-air cells, however, are based upon a classical type of oxidation/reduction reaction. The graphical description of cell operating mechanisms of Li-air and Li-ion cells are shown in Figure 1 , [ 1 , 27 , 28 , 38 ] Figure 2 [ 27 , 29 , 34 , 38 ] and Figure 3 . [ 39 ] Previously published articles are a very good starting point for any scientist or engineer who starts looking at this particular battery system. However there were no review papers published on utilized cell confi gurations (or cell types) vs. performance of the Li-air cell, which is an important aspect from an industrial point of view. For example, which cell is the most suitable for the initial stage of research? Does any schema exist for a reliable and reproducible Li-air system construction? Therefore, we set up an overall objective of this study: to understand the current issues of the Li-air cell in relation to automotive applications. To achieve this goal, throughout this study we will execute the following items as sub-level objectives. The results are presented in the subsequent sections:1. To establish and maintain our own view point for the current review; battery industry-point-of-view 2. To conduct thorough reviews on previous publications including journal papers, book chapters, patents and industrial reports based on the established view point 3. To extract reasonable conclusions and perspectives from the results of item 2There are some limitations of the current research, such as a limited study time period. Due to time constraints, we might miss some potentially important aspects related to the current survey, i.e., depending on search conditions and options in gathering materials, there is a chance that some of the published materials could be inadvertently missed. It is also probable th...