Preparation Of Ti₃C₂T_x Electrode Material And Research On Its Supercapacitor Performance

Supercapacitors have attracted attention due to high power density and long cycle life.As an important part of supercapacitors,electrode materials have became the main research object of researchers.Therefore,various functional electrode materials have been developed,such as carbon materials,conductive polymers and metal oxides.However,it is still a challenge for people to find electrode materials that have both excellent mechanical properties and high capacity.In recent years,a new family of two-dimensional nanomaterial,Ti₃C₂T_x,has been considered as a promising electrode material due to its high surface capacitance and good mechanical properties.Ti₃C₂T_xshows great advantages in the field of energy storage equipment.However,the irreversible restacking between Ti₃C₂T_xnanosheets is inevitable.It is because the strong van der Waals interaction between adjacent Ti₃C₂T_xnanosheets.The irreversible restacking results in a significant decline of accessible surface area,and seriously hinders electrochemical performance.Therefore,it is a great significance to slow down the restacking of Ti₃C₂T_xsheets and improve its electrochemical performance.This article has done the following work for the structure optimization and performance improvement of Ti₃C₂T_x.First,we etched Ti₃Al C₂ with HCl and Li F,and successfully prepared two-dimensional Ti₃C₂T_xnanosheets.The flexible Ti₃C₂T_xfilm was successfully prepared by the vacuum filtration method.The Ti₃C₂T_xfilm electrode shows excellent cycle performance,and the capacity is almost not attenuated after 10000 cycles.The two-dimensional Ti₃C₂T_xnanosheets were constructed into a three-dimensional porous structure by freeze-drying method.The three-dimensional porous structure not only prevents the restacking of Ti₃C₂T_xnanosheets,but also further improves its electrochemical performance.Porous Ti₃C₂T_xhas excellent rate performance(72.4%)and excellent electrochemical stability.In addition,we also studied the impact of electrode with different mass loadings on electrical performance.The porous Ti₃C₂T_xassemblies deliver a maximum areal capacitance of 1668 m F/cm²when the mass loading is 8.4 mg/cm².We also assembled a symmetrical solid supercapacitors.The porous Ti₃C₂T_xsolid-state supercapacitor has excellent flexibility,and capacity hardly decays under different bending conditions.At the same time,it has a high area capacitance(355.8 m F/cm²),excellent rate performance(65.2%).There is a good development prospect in the field of wearable flexible devices in the future.The introduction of metal nanoparticles improves the charge transport capability of the Ti₃C₂T_xporous structure,and makes its electrochemical activity fully utilized.Au nanoparticles were directly reduced on the surface of Ti₃C₂T_xnanosheets,and three-dimensional porous structure of Ti₃C₂T_xmodified by Au nanoparticles was obtained through a freeze-drying process.The introduction of Au nanoparticles improves the transport capacity of the entire electrode,which can provide more channels for the conduction of electrons and electrolyte ions,and improve its electrochemical performance.The experimental results show that Ti₃C₂T_x/Au NPs has high areal capacitance(610 m F/cm²),excellent rate performance(74%) and excellent cycle stability.