高倍率型MXene基复合薄膜电极的氧化重构制备与界面调控OA

MXene has exhibited considerable potential in the field of electrochemical energy storage in recent years owing to its unique layered tunable structure,abundant surface functional groups,and excellent conductivity.However,its layered structure is prone to stacking,and the surface terminal groups lack stability in oxygen-containing environments,leading to severe specific capacity decay at high scan rates.In this study,Ti3C2Tx MXene was used as the structural unit,and aramid nanofibers(ANF)served as the interfacial organic phase.Through hydrothermal oxidation reconstruction and interfacial assembly,the high-rate energy storage characteristics of MXene were effectively enhanced.The results showed that hydrothermally treated MXene(ht-Ti3C2Tx)exhibited partial oxidation and surface defluorination characteristics.The constructed ht-Ti3C2Tx/ANF electrode achieved a specific capacity of 407.9 F/g at 2 mV/s and maintained a specific capacity of 246.1 F/g even at a high scan rate of 500 mV/s,with a capacity retention rate of 60.3％,markedly superior to the untreated MXene electrode.Furthermore,the composite electrode maintained a high specific capacitance of 220.0 F/g even at a high current density of 20 A/g,demonstrating excellent rate performance.Kinetic analysis indicated that the b-value of ht-Ti3C2Tx/ANF increased to 0.90,and the charge transfer impedance decreased considerably,indicating pseudo-capacitive behavior controlled by surface reactions.The capacitance contribution increased from 86.7％at 2 mV/s to 96.8％at 50 mV/s.Simultaneously,the double-layer capacitance increased to 44.7 mF/cm2,indicating a larger electrochemically active specific surface area and faster ion transport capability.Moreover,the film exhibited good mechanical properties,with a tensile strength of 46 MPa and a toughness of 0.64 MJ/m3.The film also had a low infrared emissivity(approximately 13％)and maintained stable infrared stealth performance within the temperature range of-10℃to 200℃.This strategy provides a feasible approach for constructing MXene-based energy storage electrode materials with both high-rate performance and multifunctional characteristics.