Electrochemically induced highly ion conductive porous scaffolds to stabilize lithium deposition for lithium metal anodes
Electrochemically induced highly ion conductive porous scaffolds to stabilize lithium deposition for lithium metal anodes
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电化学诱导高离子传导性多孔支架稳定锂金属阳极的锂沉积
DOI：
10.1039/c9ta01834d
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发表时间：
2019-05-21
影响因子：
11.9
通讯作者：
Peng, Dong-Liang
中科院分区：
文献类型：
--
作者：
Chen, Qiulin;Yang, Yifang;Peng, Dong-Liang
锂(Li)金属具有较高的理论容量和较低的工作电压，被认为是下一代储能系统最有前途的负极候选材料之一。然而，由于锂沉积的不均匀和失控，导致锂枝晶的生长阻碍了它的实际应用。本论文采用磁控溅射的方法，在铜箔(锌/锌/铜)表面修饰了一层氧化锌作为锂金属阳极的集电层，构建了一种三维多孔亲锂锌(锌)支架。在锂金属沉积之前，锌/氧化锌支架会与锂离子反应，形成表面有Li2O改性层的锂锌合金支架(Li-Zn/Li2O)。表面具有高离子导电性的Li2O层会使导电表面钝化，并提供跨越表层和三维多孔Li-Zn合金支架的电位梯度。因此，锌/氧化锌@锂|锂对称电池在4 mA cm(-2)下可以稳定循环500 h以上，总容量为1 mA h cm(-2)，且极化程度较低(约40 mV)。此外，对Li4Ti5O12|锌/氧化锌@Li全电池，1000次循环后的超长循环寿命也达到了81%，这表明铜箔上的Li-Zn/Li2O多孔支架作为锂金属阳极的三维集电体具有很大的应用前景。
Lithium (Li) metal is regarded as one of the most promising anode candidates for next-generation energy storage systems due to its high theoretical capacity and low operating voltage. However, the growth of lithium dendrites caused by inhomogeneous and uncontrolled Li deposition hinders its practical application. Herein, a 3D porous lithiophilic zinc (Zn) scaffold modified with a thin zinc oxide (ZnO) surface layer on Cu foil (Zn/ZnO/Cu) as a current collector for lithium metal anodes is constructed by magnetron sputtering. The Zn/ZnO scaffold would react with Li+ ions before the deposition of lithium metal, leading to the formation of a Li-Zn alloy scaffold with a Li2O modified layer (Li-Zn/Li2O) on its surface. The surface Li2O layer with high ionic conductivity would passivate the conductive surface and provide a potential gradient across the surface layer and 3D porous Li-Zn alloy scaffold. Consequently, a Zn/ZnO@ Li| Li symmetric cell can cycle stably for more than 500 h at 4 mA cm(-2) for a total capacity of 1 mA h cm(-2) and a low polarization (around 40 mV). Moreover, an ultra-long cycling life with a high capacity retention of 81% after 1000 cycles for a Li4Ti5O12| Zn/ZnO@ Li full cell is also realized, showing that the Li-Zn/Li2O porous scaffold on Cu foil has a great prospect as a 3D current collector for Li metal anodes in the future.