聚噻吩/纳米MnO_2复合材料的制备表征及电化学性能

Preparation,characterizations and electrochemical performance of polythiophene/nano MnO_2 composite

纳米二氧化锰(MnO2)作为超级电容材料已被广泛研究。为了改善其充放电性能,采用原位化学氧化聚合法制备聚噻吩/纳米MnO2(PTh/MnO2)复合材料,对纳米MnO2进行性能改性。通过改变聚噻吩在PTh/MnO2复合材料中的掺杂量,制备出一系列的复合材料。采用傅里叶转换红外光谱(FIIR)、X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)和透射电子显微镜(TEM)对PTh/MnO2复合材料的化学性能、晶体结构以及表面形貌等进行了详细考察。接着采用CT001A型电池测试系统对以PTh/MnO2复合材料做负极所制得的密封扣式电池进行了充放电性能测试。结果表明,MnO2和聚噻吩在不同的PTh/MnO2复合材料中形貌各异。当聚噻吩含量为8wt%~10wt%时,MnO2在PTh/MnO2复合材料中分布最为均匀;当聚噻吩含量较高时,MnO2的形貌受到严重影响,其原来的管状结构接近消失。聚噻吩含量的不同,同样也影响了电池的充放电性能。当聚噻吩的含量为20wt%时,在循环20次后,电池的平衡容量为最高,可达700mAh/g。这明显高于以纳米MnO2为负极时的电池容量。由此可见,聚噻吩对纳米MnO2的充放电性能具有明显的增强作用。该研究为PTh/MnO2复合材料作为电池负极材料的使用提供了实验基础。

Nanomaterials of Manganese dioxide(MnO2) has been widely researched as the supercapacitors.To improve its charge-discharge performance,the polythiophene/nano MnO2(PTh/MnO2) composite was synthesized by the method of the in-situ chemical oxidation polymerization to modify the properties of MnO2 in the present work.A series of PTh/MnO2 composites were obtained by changing the component of polythiophene in the composites.Fourier transform infrared spectroscopy(FIIR),X-ray diffractometer(XRD),field emission scanning electron microscope(FE-SEM)and transmission electron microscopy(TEM)were used to characterize the chemical property,crystal structure,and surface morphology in detail.Afterward,the charge-discharge performances of the sealed button batteries were measured using CT001 Abattery test system,in which PTh/MnO2 composite was used as the negative electrode.The results show that the morphologies of MnO2 and polythiophene in the different PTh/MnO2 composites are various.MnO2 is uniformly distributed in PTh/MnO2 composite when the component of polythio-phene is 8wt%~10wt%.When the component of polythiophene is pretty high,however,the morphology of MnO2 is affected substantially.Its original nanotubes almost disappear.The charge-discharge property of the buttery is also affected by the ratios of polythiophene in the PTh/MnO2 composites.When the component of polythiophene is 20wt% after 20 cycles,the capacity of the buttery is highest and reaches to 700mAh/g.It is higher than that of the buttery in which nano MnO2 was used as the negative electrode.It demonstrates that the presence of polythiophene in PTh/MnO2 could enhance the charge-discharge property of MnO2.The present work could supply the experimental base for the research on the applications of PTh/MnO2 composite as the negative buttery.