Research Progress and Optimization of Non-aqueous Electrolyte for Lithium Air Batteries

Abstract

Lithium air battery is an advanced electrochemical power source that lies between fuel cell and lithium battery, and it is considered to be one of the most promising next generation batteries due to the fact that it may provide extremely high theoretical energy, i.e. 11140 Wh/kg (Li), which is estimated to be 6~9 times higher than that of the lithium ion batteries. The reason for such high theoretical energy is the use of Li sheet (with extremely high energy density) as anode electrode and O2 as cathodic reactant from the air. Other advantages of the battery include stable output voltage, cost effectiveness, and pollution free, and have broad application prospects. If it is successfully developed, the battery could be an excellent energy storage device for renewable energy sources such as wind, solar, and tidal energy, which brings a prospect for human to solve the problem of environment pollution and energy crisis. Electrolyte is a crucial component of lithium air battery and the electrochemical performance of the battery is determined by electrolyte to a great extent. Due to the react violently between lithium and water, it is not practical for lithium air battery to use directly an aqueous electrolyte unless the anode can be protected from degradation. In this paper, the authors presented the latest research progress on three kind of non-aqueous electrolyte, i.e. organic electrolyte, ionic liquid and solid electrolyte. We elaborated the influence of various chemical properties (electrochemical stability, conductivity, polarity), physical properties (dielectric constant, viscosity, oxygen solubility, hygroscopicity and electrolyte filling) and physicochemical properties (infiltration ability to cathode materials) on lithium air battery's performance, i.e. specific capacity, rate capacity and cycling efficiency. In addition, we also provided insights into the prospect of non-aqueous electrolyte for lithium air battery. © 2013 Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.