Zhou Jiahui, Xie Man, Wu Feng, Mei Yang, Hao Yutong, Li Li, Chen Renjie
Beijing Key Laboratory of Environmental Science and Engineering, School of Material Science & Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Advanced Technology Research Institute (Jinan), Beijing Institute of Technology, Jinan, 250300, China.
Adv Mater. 2022 Jan;34(1):e2106897. doi: 10.1002/adma.202106897. Epub 2021 Oct 23.
A 3D host can effectively mitigate the dendritic growth of a zinc (Zn)-metal anode. However, the increased electrode/electrolyte reaction area using the 3D substrate accelerates the passivation and corrosion at the anode interface, ultimately degrading the electrochemical performance. Here, an oriented freezing process is used to create a flexible MXene/graphene scaffold. Based on the abundant zincophilic traits and micropores in the structure, Zn is densely encapsulated inside the host by the electrodeposition process. During cycling, the composite anode endows an in situ solid electrolyte interface with zinc fluoride at the electrode/electrolyte interface due to inherent fluorine terminations in MXene, efficiently inhibiting the dendritic growth. Furthermore, the design wherein bulk Zn is distributed in a 3D microscale manner suppresses hydrogen evolution reactions (3.8 mmol h cm ) and passivation, through in/ex situ tests. As a result, in a symmetrical cell test, the electrode has a long-cycling life of over 1000 h at 10 mA cm . After continuous single folding followed by double folding, a quasi-solid-state foldable cell with the composite anode and a LiMn O cathode (60% depth of discharge) maintains high-capacity retention of over 91%. This research presents a revolutionary encapsulating idea for aqueous Zn-ion batteries, as well as foldable investigation.
三维主体可以有效减轻锌（Zn）金属阳极的枝晶生长。然而，使用三维基底增加的电极/电解质反应面积会加速阳极界面处的钝化和腐蚀，最终降低电化学性能。在此，采用定向冷冻工艺制备了一种柔性MXene/石墨烯支架。基于结构中丰富的亲锌特性和微孔，通过电沉积过程将锌致密地封装在主体内部。在循环过程中，由于MXene中固有的氟端基，复合阳极在电极/电解质界面处赋予了含氟化锌的原位固体电解质界面，有效抑制了枝晶生长。此外，通过原位/非原位测试表明，块状锌以三维微观尺度分布的设计抑制了析氢反应（3.8 mmol h cm）和钝化。结果，在对称电池测试中，该电极在10 mA cm下具有超过1000 h的长循环寿命。经过连续的单折叠和双折叠后，具有复合阳极和LiMn₂O₄阴极（放电深度60%）的准固态可折叠电池保持了超过91%的高容量保持率。本研究提出了一种用于水系锌离子电池的革命性封装理念以及可折叠研究。
