In this study, alpha-manganese dioxide/activated expanded graphite (α-MnO₂/AEG) composite was successfully synthesized using simple hydrothermal method. Morphology, structure, elemental composition and specific surface area of the material were characterised by scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD) spectroscopy, Raman spectroscopy, infrared Fourier transform spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) method. Electrochemical evaluations were achieved using three- and two-electrode configurations in 1 M Na₂SO₄ electrolyte. The maximum specific capacitance of 185.5 F g⁻¹ at 1 A g⁻¹ was recorded for three-electrode measurements. The half-cell retained an efficiency of 99.7% over 2000 cycles at 5 A g⁻¹. The fabricated device using α-MnO₂/AEG composite and activated carbon-polyvinyl alcohol (AC-PVA) as positive and negative electrodes, respectively, showed a remarkable capacitive property with a specific energy of 33 Wh kg⁻¹ and specific power of 999 W kg⁻¹ at 1 A g⁻¹ within 2.0 V cell potential. Great stability of 97.8% was observed at a specific current of 5 A g⁻¹ for over 10, 000 cycles. Further stability of the device was confirmed by performing a voltage holding of up to 70 h and retained 70% of its initial capacitance at 5 A g⁻¹.

在这项研究中，α-二氧化锰/激活膨胀石墨（α-MnO的₂ / AEG）的复合物使用简单的水热法成功地合成。通过扫描电子显微镜（SEM），高分辨率透射电子显微镜（HRTEM），能量色散光谱（EDS），X射线衍射（XRD）光谱，拉曼光谱对材料的形貌，结构，元素组成和比表面积进行了表征光谱，红外傅里叶变换光谱（FTIR）和Brunauer-Emmett-Teller（BET）方法。使用三电极和两电极配置在1 M Na ₂ SO ₄电解质中进行电化学评估。的185.5 F G的最大比电容^-1 1 A G ^-1记录三电极测量值。半电池在5 A g ^-1的2000个循环中保持了99.7％的效率。使用α-MnO的所制造设备₂ / AEG复合材料和活性炭-聚乙烯醇（AC-PVA）作为正极和负极，分别显示出显着的电容特性具有33瓦kg的比能量^-1比功率999的和在2.0 V电池电势下于1 A g ^-1时的W kg ^-1。在5 A g ^-1的比电流下，经过10 000次循环，观察到97.8％的出色稳定性。通过执行长达70 h的电压保持并在5 A g ^-1下保持其初始电容的70％，可以确认该器件的进一步稳定性。