Na[FSA-C(2)C(1)im][FSA] (C(2)C(1)im(+): 1-ethyl-3-methylimidazolium and FSA : bis(fluorosulfony) amide) ionic liquid was utilized as the aprotic electrolyte in hybrid sodium-air cells for the first time. The sodium-air cells were operated at relatively high temperatures up to 70 degrees C to prove their excellent thermal stability. A large output power density was obtained by increasing the operation temperature because of the high Na+ diffusivity and high ionic conductivity of the ionic liquid. The cells exhibited an extremely large specific capacity of 835 mAh g (1) at 50 degrees C; this capacity corresponds to 99% of the theoretical capacity. In addition, maximum areal output power density of 27.6 mW cm (2) was obtained at 50 degrees C. The Na[FSA-C(2)C(1)im][FSA] ionic liquid was proved to be a promising aprotic electrolyte to enhance the electrochemical performance of hybrid sodium-air cells. (C) 2016 Elsevier Ltd. All rights reserved.