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Stable Metal Anode enabled by Porous Lithium Foam with Superior Ion Accessibility
Advanced Materials ( IF 27.4 ) Pub Date : 2018-06-14 , DOI: 10.1002/adma.201802156
Ahmed M. Hafez 1 , Yucong Jiao 1 , Jianjian Shi 2 , Yi Ma 1 , Daxian Cao 1 , Yuanyue Liu 2 , Hongli Zhu 1
Affiliation  

Lithium (Li) metal anodes have attracted much interest recently for high‐energy battery applications. However, low coulombic efficiency, infinite volume change, and severe dendrite formation limit their reliable implementation over a wide range. Here, an outstanding stability for a Li metal anode is revealed by designing a highly porous and hollow Li foam. This unique structure is capable of tackling many Li metal problems simultaneously: first, it assures uniform electrolyte distribution over the inner and outer electrode's surface; second, it reduces the local current density by providing a larger electroactive surface area; third, it can accommodate volume expansion and dissipate heat efficiently. Moreover, the structure shows superior stability compared to fully Li covered foam with low porosity, and bulky Li foil electrode counterparts. This Li foam exhibits small overpotential (≈25 mV at 4 mA cm−2) and high cycling stability for 160 cycles at 4 mA cm−2. Furthermore, when assembled, the porous Li metal as the anode with LiFePO4 as the cathode for a full cell, the battery has a high‐rate performance of 138 mAh g−1 at 0.2 C. The beneficial structure of the Li hollow foam is further studied through density functional theory simulations, which confirms that the porous structure has better charge mobility and more uniform Li deposition.

中文翻译:

多孔锂泡沫可实现稳定的金属阳极,并具有出色的离子可及性

锂(Li)金属阳极最近在高能电池应用中引起了人们的极大兴趣。但是,库仑效率低,体积变化无限以及严重的枝晶形成限制了它们在广泛范围内的可靠实现。在此,通过设计高度多孔和中空的Li泡沫,可以显示Li金属阳极的出色稳定性。这种独特的结构能够同时解决许多锂金属问题:首先,它可以确保电解质在内部和外部电极表面上的均匀分布;其次,它通过提供更大的电活性表面积来降低局部电流密度。第三,它可以容纳体积膨胀并有效地散热。此外,与低孔隙率的完全覆盖锂的泡沫以及体积庞大的锂箔电极对应物相比,该结构显示出优异的稳定性。-2)和4 mA cm -2下160个循环的高循环稳定性。此外,在组装时,以多孔锂金属为阳极,以LiFePO 4为正极用于整个电池,该电池在0.2 C时具有138 mAh g -1的高倍率性能。空心锂泡沫的有益结构是通过密度泛函理论仿真进一步研究,证实该多孔结构具有更好的电荷迁移率和更均匀的Li沉积。
更新日期:2018-06-14
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