Construction And Electrochemical Energy Storage Performance Of Hierarchical Ti₃C₂T_x/polyaniline Hybrid Materials

Owing to the high-power density and long cycling lifetime,Supercapacitors have emerged as a promising alternative energy storage device being used in portable devices,electric vehicle and other industrial power supplies.However,High volumetric energy density is imperative for the miniaturization of electric devices.In this study,two-dimensional material?Ti₃C₂T_x?was selected as substrate and incorporate with polyaniline to construct hierarchical hybrid electrodes.The resulted inorganic-organic hybrid electrodes,which combined different functional domains,can effectively suppress PANI lossing and Ti₃C₂T_x sheet re-stacking during the long-term cycling times and finally enhance the volumetric capacitance and gravimetric capacitance of Ti₃C₂T_x hybrid electrodes by triggering synergistic effects.?1?Ti H₂,TiC and Al powder were chosen as initial materials to synthesis high purity precursor?Ti₃AlC₂?by using optimized method.And the etching and intercalation processing were controlled to synthesis high quality and defect-free Ti₃C₂T_x nanosheets.The as-prepared Ti₃C₂T_x nanosheets with high conductivity and uniformly distribute terminal groups?such as–F,–OH,and–O–?,which can form a strong electrostatic interaction with aniline molecules towards in-situ polymerization of PANI nanolayer.?2?The hierarchical inorganic-organic hybrid materials?MX/PA?were constructed,which capture and enrich aniline molecules to in-situ polymerization uniformly distributes PANI nanolayer on the surface of Ti₃C₂T_x sheets.The characterization of nanostructure confirms that PANI nanolayer were robust bonding and intercalated with Ti₃C₂T_x sheets.And the electrochemical tests show that the electrochemical performance of MX/PA hybrid electrodes were highly dependent on the PANI loading rate.Moreover,ions transport mechanism analysis provides another evidence that the low PANI loading could fully utilize high energy density of polyaniline nanolayer without blocking the gaps between Ti₃C₂T_x sheets.Furthermore,suprcapacitor performances show that this novel MX/PA hybrid electrode achieves a significantly enhanced capacitance(882 F cm^-3)with 4.9%PANI loading,and the hybrid electrode achieves an excellent cycling stability with 83%capacitance retention over 5000 cycles,which was much higher than that of the Ti₃C₂T_x and polyaniline materials of a single component.?3?MX/rGO xerogels was constructed by combination highly conductive Ti₃C₂T_x nanosheets with large specific area of reduced graphene?rGO?.Then,MX/rGO drives a unique self-adsorption polymerizatioin of aniline monomers.The aniline monomers were captured and enriched on the porous network of MX/rGO xerogels into uniform and ordered aniline multilayers,and upon polymerization,a polyaniline nanofilm is evenly coated on sheet surface through strong interfacial bonds.Thus,the polymer conductive skeleton was stabled by grafting on MX/rGO network,and suppress their own swelling and degradation during charging and discharging.Moreover,the PANI nanolayer significantly enhanced the volumetric capacitance(929 F cm^-3)and gravimetric capacitance(645 F g^-1)of MX/rGO xerogels.Therefore,this hierarchical nanostructure paves a way to simple and efficient method to design Ti₃C₂T_x-based hybrid electrodes.