Synthesis Of CoNi-LDH/Ti₃C₂ MXene Nanocomposites For Sodium Ion Battery Applications

Sodium ion batteries are promising to become a new generation of battery products in the energy storage field because of their excellent characteristics such as cheap and affordable,large abundance.Due to the large ionic radius of sodium ions(1.02?),the process of sodium ion detachment and mosaic will lead to the volume expansion of the material and thus the structure of the material will be destroyed,which will eventually lead to the poor cycling performance of the battery.Ti₃C₂MXene,as a new type of 2D nanomaterial,is favored by researchers for its unique layer-like structure and excellent charge transport capability.It has been indicated that Ti₃C₂MXene is mainly dominated by capacitive behavior during sodium ion storage.Such a storage method requires that when sodium ions enter the material,they are inserted between the layers of Ti₃C₂MXene instead of inside the lattice.This way of sodium ions entering the material can avoid the phenomenon of volume expansion of the material,so Ti₃C₂MXene is considered to be a new generation of energy storage material for sodium ion batteries.However,when Ti₃C₂MXene is actually used as anode material for sodium ion batteries,agglomeration and stacking between Ti₃C₂MXene sheets can occur,and the functional groups on the surface of the material are prone to oxidation leading to a significant decrease in the electrochemical performance of the material.To avoid the effects of agglomeration and self-stacking phenomena on the electrochemical properties of the material,another two-dimensional nanomaterial Co Ni-LDH was introduced into Ti₃C₂MXene.After structural and performance characterization of the composite,it was found that Co Ni-LDH was compounded with Ti₃C₂MXene by forming chemical bonds with the functional groups on the surface of Ti₃C₂MXene.It can play a supporting role to prevent the agglomeration of Ti₃C₂MXene lamellae and increase the layer spacing of Ti₃C₂MXene to improve the migration rate of sodium ions.The Ti₃C₂MXene as the conductive backbone of the material can alleviate the volume expansion problem of Co Ni-LDH during charging and discharging,so the obtained composite has excellent multiplicity performance and long cycle life at high current density when used as anode material for sodium ion batteries.Graphene oxide(GO)is a unique graphene-based two-dimensional nanomaterial that can be used in the study of energy storage devices due to its unique two-dimensional structure.With the development of graphene surface functionalization,the storage capacity of the material for sodium ions can be improved by adjusting the morphology of the material surface.In this experiment,the purpose of changing the surface morphology of the material is achieved by treating GO with sodium sulfide solution,and the results show that the surface of GO treated with sodium sulfide solution has more active sites and exhibits excellent multiplicative performance.