MXene材料的合成方法及其作为锂金属负极宿主的应用综述

A review of synthesis method and application of MXenes as host in lithium metal anodes

  • 摘要: 锂金属直接用作负极时,在循环过程中面临枝晶生长和体积膨胀的问题,导致固态电解质界面(SEI)层断裂和重复形成,消耗活性物质和电解质,进而降低电池的库仑效率并导致容量快速衰减。设计具有快速传质和足够存储空间的基体是促进锂的均匀沉积、减少SEI重复生长和死锂形成的有效方法。具有二维层状结构的MXenes由于具有优异的导电性、可调控的层间距、丰富的亲锂表面官能团和优异的机械性能而被认为是良好的锂金属宿主。本综述首先总结了MXenes的多种合成方法,包括借助外部试剂蚀刻前驱体MAX相、化学气相沉积、UV诱导蚀刻和机械化学等方法。不同的合成方法会形成不同表面官能团和层状结构的MXene,进而影响锂金属的成核和生长行为。随后,介绍了纯MXene,MXene-碳杂化物和MXene-非碳杂化物在锂金属负极宿主中的应用,主要关注其缓解锂金属负极体积变化并抑制锂枝晶生长方面的性能。最后,对一些改性策略和潜在的研究方向进行了总结和展望。

     

    Abstract: Severe dendritic growth and volume expansion are easily induced during the cycling process when lithium metal is used as an anode electrode directly. These problems cause the solid electrolyte interface (SEI) layer to break and re-form, which consumes the active lithium metal and electrolyte, thereby reducing the Coulomb efficiency and rapid capacity. Designing a host matrix with rapid mass transfer and enough storage space to promote lithium homogeneous deposition, hence reducing the repeated SEI growth and the formation of dead lithium, is an effective method to address the concerns mentioned above issues. MXenes with two-dimensional layered structures have been regarded as feasible hosts for stabilizing lithium due to their superior electrical conductivity, sizeable interlayer space, abundant lithiophilic surface functional groups, and excellent mechanical properties. In this review, we first summarized the multiple synthesis methods of MXenes, including etching the precursor MAX phase, chemical vapor deposition, UV-induced etching, and mechanochemical et al. Various synthesis methods would induce different surface termination and lamellar structures, affecting lithium metal nucleation and growth behavior. Subsequently, pure MXene, MXene-carbon and MXene-non carbon hybrid compounds applied for lithium metal anode hosts were introduced, focusing on alleviating noticeable volume changes and inhibiting lithium dendrite growth. Finally, some modification strategies and potential research prospects were summarized and prospected.

     

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