N、B共掺杂MXene复合材料的制备及其电化学性能研究

Preparation and characterization of electrochemical properties of nitrogen and boron co-doped MXene composite materials

通过对Ti_3AlC_2MAX相陶瓷粉进行刻蚀、插层、超声处理,制备出片状Ti_3C_2T_x MXene。以离子液体1-丁基-3-甲基咪唑四氟硼酸盐作为杂原子掺杂的氮源和硼源,通过不同温度热处理,得到新型的N、B掺杂MXene(N,B-Ti_3C_2T_x)作为超级电容器的电极材料。考察了煅烧温度对其电容性能的影响,结果表明,最佳煅烧温度为300℃,此时电容性能得到有效提高。在扫描速率为100 mV/s时测得N,B-Ti_3C_2T_x-300℃的质量电容为65 F/g,是相同条件下Ti_3C_2T_x电容的5.5倍。EIS结果表明,N,B-Ti_3C_2T_x-300℃的接触电阻为0.52?。循环稳定性测试表明,当电流密度为2 A/g时,充放电循环1000次后的电容保持率为84%。

Ti3C2Tx MXene sheets were prepared by etching Ti3AlC2MAX ceramic powders,followed by intercalation and ultrasonic exfoliation.With an ionic liquid,1-butyl-3-methylimidazolium tetrafluoroborate,as a heteroatom-doped N and B source,a new type of N,B-doped MXene(N,B-Ti3C2Tx)was synthesized by heat treatment of the MXene at different temperatures,and used as an electrode material for supercapacitor fabrication.The influence of annealing temperature to capacitive performance was studied,and the results indicates that the capacitance performance was effectively improved at a calcination temperature of300℃.The mass capacitance of N,B-Ti3C2Tx-300℃was measured to be65F/g at a scan rate of100mV/s,which was5.5times higher than that of Ti3C2Tx.The EIS showed that the contact resistance of N,B-Ti3C2Tx-300℃was0.52Ω.The capacitance retained84%at a current density of2A/g after1000cycles.