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Pseudocapacitance Induced Uniform Plating/Stripping of Li Metal Anode in Vertical Graphene Nanowalls
Advanced Functional Materials ( IF 19.0 ) Pub Date : 2018-10-21 , DOI: 10.1002/adfm.201805638
Feihong Ren 1 , Ziyu Lu 2 , Huan Zhang 3 , Liyuan Huai 4 , Xinchun Chen 5 , Sudong Wu 4 , Zhe Peng 4 , Deyu Wang 4 , Jichun Ye 4
Affiliation  

Unevenly distributed dendrite growth is usually viewed as a consequence to the diffusion‐limited interface instability during electrodeposition, leading to one of the most serious obstacles hindering the application of high‐capacity lithium (Li) metal anodes. Herein, a fundamental issue of modifying Li plating behavior using a structure of 3D vertical graphene nanowalls on nickel (Ni) foam (VGN/Ni) is investigated. Such a structure exhibits a significant pseudocapacitive interfacial feature, greatly improving the Li+ ion transfer kinetic through the structure, and exhibiting uniform Li plating/stripping for stable Li metal cycling even at a high depth of discharge of 50%. Based on such a structure, high Coulombic efficiencies ≈97% and 99% can be obtained in carbonate and ether electrolyte over long‐term cycling. The symmetrical cell based on the VGN/Ni@Li composite anodes can afford a stable cycling of 2000 h with low voltage hysteresis of 30 mV. Full cell system using VGN/Ni@Li composite anode and LiFePO4 cathode is also proved, with high capacity retention of 89.4% at the 1000th cycle. The pseudocapacitance induced benefits, which have not yet been elucidated for Li metal anodes, can conduct to underlying strategy in designing stable Li metal host for high‐energy‐density batteries.

中文翻译:

伪电容诱导垂直石墨烯纳米壁中锂金属阳极的均匀电镀/剥离

通常认为树枝状晶体分布不均匀是电沉积过程中扩散受限的界面不稳定性的结果,这是阻碍高容量锂(Li)金属阳极应用的最严重的障碍之一。在本文中,研究了使用镍(Ni)泡沫(VGN / Ni)上的3D垂直石墨烯纳米壁的结构来修饰Li镀层行为的基本问题。这样的结构表现出明显的伪电容界面特征,极大地改善了Li +离子在整个结构中传递动力学,并且即使在50%的高放电深度下,也显示出均匀的Li镀层/剥离层,以实现稳定的Li金属循环。基于这种结构,在长期循环中,碳酸盐和醚类电解质中的库仑效率分别约为97%和99%。基于VGN / Ni @ Li复合阳极的对称电池可提供2000 h的稳定循环以及30 mV的低压滞后。还证明了使用VGN / Ni @ Li复合阳极和LiFePO 4阴极的全电池系统,在第1000个循环时具有89.4%的高容量保持率。假电容引起的好处,对于锂金属阳极尚未被阐明,可以在为高能量密度电池设计稳定的锂金属主体时遵循基本策略。
更新日期:2018-10-21
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