锂-空气电池性能的影响因素及研究进展

Research Progress and the Limiting Factors that Affect Performance of the Lithium Air Batteries

锂-空气电池理论比能量高达3622 Wh kg-1(设阴极还原产物为Li2O2),远超过目前已有的任何电池,有希望成为新一代的二次电池.然而,目前其实用化研究还处于探索阶段,在其商用之前还有许多工作要做.对影响锂-空气电池性能的因素以及近期的研究进展进行综述,总结了阴极材料的组成和微观结构、电解质的种类及组成、阴极疏水膜、电池结构设计、电池的组装及充、放电的工艺过程等对电池比能量、比容量以及循环性能等的影响,概述了锂-空气电池的表征手段,并对锂-空气电池的应用前景进行了展望.

Lithium air battery has attracted extensive attention due to its potential in achieving much higher practical specific energy than existing batteries, and it may become one of the most promising next generation battery technologies. Lithium air battery has the compelling advantage of theoretical specific energy, i.e. 3622 Wh·kg^-1 （assuming Li2O2 is the product）, which is attributed to the use of a lithium metal anode and the ready availability of the cathode oxidant, i.e. oxygen, from the surrounding air. Other advantages include stable potentials, high safety, low cost, friendly to environment. However, before Lithium air batteries can be commercialized, the following challenges still need to be overcome： optimization of the cathode materials structure and the electrolyte composition, enhancement of the actual discharge special capacity, and improvement of the cycle performance and elucidating the reaction mechanism that occurs during charge and discharge. In this paper, we presented the current research progress and the limiting factors that affect performance of the batteries, such as microcomposition and microstructure of the cathode materials, constitution of the electrolytes, oxygen selective membranes, the structure design for the lithium air batteries, charge and discharge mechanism; compared lithium air battery with other advanced batteries, i.e. lithium air battery, lithium ion battery, lead-acid battery, nickel-hydride battery and fuel cells electrochemical properties, such as specific capacity, specific energy, specific power and open circuit voltage; summarized the effect of the composition and structure of the cathode materials on its performance; discussed the merits and demerits of aqueous electrolyte, non-aqueous electrolyte and dual-electrolyte for Li-air batteries; analyzed the effect of solubility coefficient, conductivity and viscosity of various components non-aqueous electrolytes, established the heterogeneous reaction model of cathode in organic electrolyte and aqueous electrolyte and reviewed state-of-the-art characterization techniques of the materials for lithium air batteries and the application prospect of lithium air battery.