锰氧化物/N-掺杂碳复合材料的制备及电化学性能研究

Preparation and electrochemical properties of manganese oxide/N-doped carbon composites

为了得到一种高功率密度、高比电容和长循环寿命的电极材料,通过苯胺(An)气体与高锰酸钾(KMnO_(4))水溶液之间的气-液界面反应合成了二氧化锰/聚苯胺(MnO_(2)@PANI)纳米复合材料,然后将制得的MnO_(2)@PANI纳米复合材料置于管式炉中,在氩气保护下,高温700℃的条件恒温煅烧2 h,得到锰氧化物/碳(MnO_(x)@C)的复合材料。通过扫描电子显微镜、X射线衍射仪、比表面积及孔径分析仪、傅里叶变换红外光谱仪和X射线光电子能谱仪对产品进行了成分、结构和微观形态的分析。电化学测试结果显示,MnO_(x)@C具有更高的电压范围(-1~1 V),较为优异的比电容(215 F/g,1 A/g),较为理想的倍率性能(当电流密度从1 A/g增加到10 A/g时,比电容保持率为56%),并且具有较长的循环寿命(在5 A/g电流密度下经过5000次充放电循环后,比电容仍保持96.2%)。证实通过引入碳材料的方法可以有效地改善锰基超级电容器电极材料的比电容、倍率性能和循环稳定性。

To obtain an electrode material with high power density,high specific capacitance,and long cycle life,manganese dioxide/polyaniline(MnO_(2)@PANI)nanocomposite materials were synthesized through the gas-liquid interface reaction between aniline(An)gas and potassium permanganate(KMnO_(4))aqueous solution.The MnO_(2)@PANI nanocomposite materials were then placed in a tubular furnace and annealed at a constant temperature of 700℃ under argon protection for 2 hours,resulting in the formation of manganese oxide/carbon(MnO_(x)@C)composite materials.The composition,structure,and microstructure of the products were analyzed using scanning electron microscope,X-ray diffractometer,specific surface area and pore size analyzer,Fourier transform infrared spectrometer,and X-ray photoelectron spectrometer.The electrochemical test results show that MnO_(x)@C has a higher voltage range(-1-1 V),excellent specific capacitance(215 F/g,1 A/g),ideal rate performance(the specific capacitance retention is 56% when the current density increases from 1 A/g to 10 A/g),and a longer cycle life(after 5000 charge-discharge cycles,the specific capacitance retention remains 96.2% at a current density of 5 A/g).Thus the introduction of carbon materials can effectively improve the specific capacitance,rate performance,and cycling stability of manganese-based supercapacitor electrode materials.