Improving The Energy Storage Of Mg Batteries By Using The Pillared MXene Through Computational Study

In the era of globalization and industrialization,fossil energy such as oil and coal h as become an indispensable energy source for development.With the increase of usage,the reserves are sharply reduced,and the environmental pollution is increasingly serious.In the face of long-term safety and environment problems,it is extremely necessary to explore alternative battery technology,for making rechargeable batteries using electrodes containing polyvalent metal ions(Zn²⁺,Mg²⁺,Al³⁺,etc.)is considered a promising strategy,because rechargeable water-magnesium ion batteries（MIBs）show great promise in various energy storage technologies,showing ultra-high theoretical specific capacity,environmental friendly,good low electrode potential and good chemical stability.The most important is that the positive electrode of Mg metal battery is less prone to dendrite growth than that of Li.However,the positive electrode of Mg battery will undergo irreversible changes in volume and structure during charging and discharging,resulting in poor cycling stability,rapid capacity loss and poor electrochemical performance.In order to overcome these limitations,the strut method can be used as an effective strategy to offset the variation of intermediate spacing during the charge or discharge process of two-dimensional material cells.In the columnar structure,the layers are chemically connected by molecular linkers,thus improving the mechanical and electrochemical stability of the electrode during its cycle life.In order to realize the pillared two-dimensional frame structure,By using density functional theory calculation,we proposed to screen one molecule from C₆H₄O₂,C₆Cl₄O₂,C₆H₆,C₆F₄O₂and C₆Cl₆as the interlayer linker of Ti₃C₂O₂,and then add the benzoquinone molecular linker to Ti₃C₂T₂MXene layered structure,wherein benzoquinone molecular linker has vertical adsorption,horizontal adsorption,and initial maintain a certain Angle adsorption three ways,through the calculation to select the most stable structure..Through calculation,the most stable structure is selected to realize the pillar frame structure.The simulation results show that the diffusion ability and stability of adsorbed Mg on the pillared structure can be significantly improved,which proves that the pillared MXene can significantly enhance the stability of Mg positive electrode,it is more important.