Preparation And Properties Of Solid Oxide Electrolyte For Lithium-Air Batteries

With high-capacity, low-cost advantages, lithium-air batteries is expected to replace lithium-ion battery to solve the bottleneck of the development of new energy vehicles. In order to solve the problem of the accumulation of lithium-air battery product which increases the cathode polarization, it is designed the organic electrolyte system with inorganic solid electrolyte to separate the mixture of inorganic, and the ionic conductivity of the solid electrolyte is the key step to limit the battery energy density. Compared to the high lithium ion conductivity of single crystal Li3N, LiI-Li2S-B2S3 glass electrolyte, NASICON and LISICON-type electrolyte also has a high ionic conductivity and chemical stability and electrochemical stability, chemical stability and electrochemical stability. This paper choose the NASICON-type LTAP electrolyte and LISICON-type LLTO electrolyte as the main object of study, explored the impact of the preparation methods and conditions on the electrical conductivity, and had a preliminary application.in the lithium-air battery.LTAP electrolytes were prepared by mechanical milling and electrospinning methods, almost the same effect was found after prepared the two ways. SEM tests were found that the material particles prepared by electrospinning in the range of a few hundred nanometers, and the apparent density of the film prepared by electrostatic spinning was sligtly lower. The modification by doped silicon and lithium, which can significantly reduce the resistance of the grain boundary, which can reach 3.8×10-4S/cm, its conductivity with temperature following the Arrhenius formula, the conductivity activation energy up to 0.319eV, fully meet the the battery application level.LLTO materials were prepared by electrospinning, and sintering conditions were identified of 700℃5h +900℃10h, the material particle size ranges in 200nm ~ 1000nm, a conductivity of 1.5×10-6S/cm, better than the microwave synthesis method, but less than the conventional sintering method. Comparing the conductivity of the LLTO pressed by cold pressing, it is found that density was not the conductivity controlling factors, but the reasonable number of the lithium-ion vacancy.Using the LTAP and LLTO as the electrolyte in the water system lithium-air batteries, it is found that the open circuit voltage was 3.6V, charge and discharge voltage was 4.2V and 2.7V, but the capacity was lower, need further exploration and research.