基于锂-氧气反应的锂-空气电池在所有的锂电池体系中具有最大的理论容量和能量密度,认识锂-空气电池中的氧气电极反应对锂-空气电池的研发具有指导意义.本文以金电极/乙腈电解液为模型体系,介绍了锂-空气电池在放电和充电过程中的氧气电极反应机理.电池放电时,氧气还原成超氧自由基,超氧自由基与锂离子结合生成不稳定的超氧化锂；通过歧化反应,超氧化锂生成放电反应最终产物过氧化锂.电池充电时,过氧化锂通过一步两电子直接氧化生成氧气,不经过超氧化锂中间态.在阐述氧气电极反应机理的同时,还对研究氧气反应的各种电化学方法作了介绍.%Li-air batteries utilizing Li-O2 reactions have the highest theoretical capacity and energy density in the Li-battery family, and potentially have the ability to transform energy storage. Thus, it is crucial to understand the oxygen reaction mechanism in Li+ electrolyte because it is the core reaction occurring in the Li-air cells currently under intense R&D. This review summarized the oxygen reaction mechanism during discharge and charge of a nonaqueous Li-air cell by taking Au/CH3CN as a model system; On discharge, O2 is reduced to O2, which then forms LiO2 on the electrode surface which disproportionates to Li2 O2. On charging, Li2 O2 decomposes directly, in a one-step reaction to evolve 02 and does not pass through LiO2 as an intermediate. Along with presenting the oxygen reaction mechanism, the relevant electrochemical methods are also described.
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