Separation of Reaction and Storage in Li-Air Battery

Non-aqueous Li-air battery has intensively been investigated due to its ultla-high energy density, however, its serious concerns have not been completely solved yet, such as severe cycle fading and low current density. The major cause of the issues can be attributed to a deposition of discharge product on the cathode surface because the deposition results in a clogging of the pore in the cathode preventing continuous steady discharge and in its chemical and/or physical electronic isolation from cathode even after charge. 1 In other words, a fundamental difficulty which resides in Li-air architecture can be described as; ‘electrochemical reaction and discharge product storage take place at the same location, on the cathode’ . Based on the discussion, we simply came to the conclusion that we needed to separate ‘ electrochemical reaction and discharge product storage’ to solve above-mentioned fundamental issues. In this presentation, we propose a new concept Li-air battery which discharge product (Li 2 O 2 ) can be stored in its electrolyte instead of on the cathode (fig. 1). The new battery architecture can be realized by simply replacing its original electrolyte to a new composite one. The cathode is able to maintain itself in a steady state during discharge because the discharge product is not deposited on it, and the new Li-air has performed much higher current density and capacity than the regular (old) architecture Li-air (fig. 2). We also demonstrate performances of the new Li-air even in the ambient air operation. Y. Hase, E. Ito, T. Shiga, F. Mizuno, H. Nishikoori, H. Iba, K. Takechi, Chem. Commun ., 49 , 8389 (2013). Figure 1