Abstract:
MXenes(Mn+1XnTx) is a class of two-dimensional inorganic compound materials composed of transition metal carbides, nitrides or carbonitrides with several atomic layers thick. Its precursor is MAX(Mn+1AX), where M mainly represents the transition metal elements, such as Ti; X is carbon and/or nitrogen; Tx represents the functional groups introduced in the reaction process, such as OH,H,F, etc. A mainly represents group 13 and group 14 elements, such as Al and Si. In 2011, Gogotsi, Barsoum et al first reported the preparation of Ti3C2Tx by selective etching of Al layer using Ti3AlC2 MAX phase precursor impregnated with HF solution. Due to its advantages such as large specific surface area, fast charge-discharge performance and small volume change, it was first used in the research of lithium ion battery anode material by Simon and Gogotsi's research group in 2012, Since then, MXenes materials have attracted a lot of attention. Researchers hope to use MXenes to develop large capacity, high safety, excellent performance of lithium-ion battery anode materials, so as to improve the energy density and battery life. However, the multilayer MXene material will produce the collapse and accumulation of the layered structure during the preparation process, resulting in a large reduction of the contact area, thus reducing the electron and ion transport capacity of the MXene material perpendicular to the layer structure. At present, by combining MXene with other materials to prepare materials with new structures, researchers can not only improve the structure, expand the layer spacing, but also help improve its electrochemical properties. This paper reviews the research strategies to improve the electrochemical properties of MXenes materials by doping with transition metal oxides, transition metal sulfides and silicon, as well as the scheme to achieve stable and dendrite-free metal anode by using MXenes materials and high capacity anode materials. Finally, the challenges faced by MXenes as anode materials for lithium ion batteries in the future are analyzed and prospectedct.