Highly efficient and stable solid-state Li-O-2 batteries using a perovskite solid electrolyte

Abstract

The solid-state Li-O-2 battery is considered an ideal candidate for high-performance energy storage because of its high safety, due to use of non-flammable and non-volatile electrolytes, and high specific energy, as it uses Li metal and O-2 gas as active materials. We present an original solid-state Li-O-2 cell composed of a Li metal anode, a flexible polymer interlayer, a perovskite-structured Al-doped Li-La-Ti-O (A-LLTO) solid electrolyte, and an integrated cathode in which a porous A-LLTO solid electrolyte frame was covered with a carbon layer and CoO nanoparticles as the catalyst for the cyclic oxygen evolution and reduction reactions. The designed solid-state cell operated safely in pure O-2 atmosphere at temperatures from 25 degrees C to 100 degrees C and delivered the first discharge capacity from 796 mA h g(C+CoO)(-1) to 4035 mA h g(C+CoO)(-1), respectively, at a current density of 0.05 mA cm(-2). Notably, at 50 degrees C, the cell was maintained for 132 cycles under a limited capacity mode of 500 mA h g(C+CoO)(-1) at a high current density of 0.3 mA cm(-2), demonstrating the first step of success towards realizing Li batteries with high energy and cyclability, as well as safety.