H2O self-trapping air cathode of Li-O-2 battery enabling low charge potential operating in dry system
H2O self-trapping air cathode of Li-O-2 battery enabling low charge potential operating in dry system
复制标题
Li-O-2 电池的 H2O 自捕空气阴极可在干燥系统中实现低充电电位
DOI：
10.1016/j.nanoen.2019.103945
复制
发表时间：
2019
期刊：
影响因子：
17.6
通讯作者：
Zhou Haoshen
中科院分区：
文献类型：
--
作者：
Mu Xiaowei;Jiang Jie;Deng Han;Qiao Yu;Zheng Mingbo;Zhang Xueping;He Ping;Zhou Haoshen
最近有报道称，涉及H2O的Li-O2电池电化学显示出降低的充电过电位。然而，电解液中的水扩散到锂阳极侧将不可避免地腐蚀锂金属并严重降低电池性能。本文提出了一种“H2O自捕获”的活化石墨烯阴极，以保留一定量的结合水，这些结合水将参与干体系Li-O2电池的电化学反应。在捕获水的参与下，在约3.3V处获得超低电荷平台，这主要归因于LiOH的电化学分解。这是第一次在完全放电-再充电过程中使用纯碳阴极实现如此优异的往返效率。此外，这些结果为“H2O自捕集”阴极存在下的水催化作用提供了有力的证据，这对设计优化的阴极材料具有指导意义，将用于更实用的Li-O2电池。
Li–O2battery electrochemistries involved H2O have been reported to show reduced charge overpotential recently. However, water in electrolyte diffusing to Li anode side will inevitably corrode Li metal and degrade battery performance severely. Herein, a “H2O self-trapping” cathode of activated graphene is proposed to reserve certain amount of bound water, which will participant in the electrochemistry reactions of Li–O2batteries in dry system. Under the participation of trapped water, an ultra-low charge plateau at about 3.3 V obtained, which is mainly attributed to the electrochemical decomposition of LiOH. This the first time that such excellent round-trip efficiency achieved using pure carbon cathodes during fully discharge-recharge process. Moreover, these results provide convictive evidence of the water catalysis in the presence of a “H2O self-trapping” cathode, which are instructive for the design of optimized cathode materials that will be used in more practical Li–O2batteries.