Reversible Oxygen Redox Chemistry in Aqueous Zinc-Ion Batteries
Reversible Oxygen Redox Chemistry in Aqueous Zinc-Ion Batteries
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DOI：
10.1002/anie.201902679
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发表时间：
2019-05-20
影响因子：
16.6
通讯作者：
Chen, Jun
中科院分区：
文献类型：
--
作者：
Wan, Fang;Zhang, Yan;Chen, Jun
可充水溶液锌离子电池具有成本低、安全性高等优点，是一种很有前途的储能装置。然而，它们的能量储存机制是复杂的，并没有很好地建立起来。目前ZIB的储能机制通常依赖于阳离子氧化还原过程。由于阴极和电解质的限制，尚未观察到阴离子氧化还原过程。在此，我们描述了基于层状VOPO 4阴极和盐包水电解质的高度可逆的含水ZIB。这样的电池在高电压区域中显示可逆的氧氧化还原化学。氧氧化还原过程不仅提供约27%的额外容量，而且还将平均工作电压提高到约1.56V，从而将能量密度提高约36%。此外，氧的氧化还原过程促进了VOPO 4在充/放电过程中的可逆晶体结构演变，从而提高了倍率性能和循环性能。
Rechargeable aqueous zinc-ion batteries (ZIBs) are promising energy-storage devices owing to their low cost and high safety. However, their energy-storage mechanisms are complex and not well established. Recent energy-storage mechanisms of ZIBs usually depend on cationic redox processes. Anionic redox processes have not been observed owing to the limitations of cathodes and electrolytes. Herein, we describe highly reversible aqueous ZIBs based on layered VOPO4 cathodes and a water-in-salt electrolyte. Such batteries display reversible oxygen redox chemistry in a high-voltage region. The oxygen redox process not only provides about 27% additional capacity, but also increases the average operating voltage to around 1.56V, thus increasing the energy density by approximately 36%. Furthermore, the oxygen redox process promotes the reversible crystal-structure evolution of VOPO4 during charge/discharge processes, thus resulting in enhanced rate capability and cycling performance.