A review of the use of Mxenes as hosts in lithium metal anodes and the anode formation

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.