Several key issues of aqueous lithium/air rechargeable batteries that consists of a water-stable lithium electrode, an aqueous electrolyte, and a bifunctional air electrode are reviewed. Based on research and discussion of these issues, the challenges and prospects for high energy density aqueous lithium/air rechargeable batteries are described. From a broader perspective, lithium/air rechargeable batteries that employ aprotic electrolytes are also briefly introduced for comparison.