Tonu Nusrat Tazeen, Yousuf Mohammad Abu, Ahamed Parbhej, Hasan Md Mahfujul
Department of Chemistry, Khulna University of Engineering and Technology Khulna 9203 Bangladesh
Chemistry Discipline, Khulna University Khulna 9208 Bangladesh.
RSC Adv. 2025 May 9;15(19):15318-15336. doi: 10.1039/d5ra00543d. eCollection 2025 May 6.
In this study, an ultrasonic-aided reverse micelle formation, followed by the calcination route, was developed for the synthesis of bixbyite microdice aimed at the fabrication of a cathode for ARZIBs. The prepared product was MnO having crystallinity and grain size of 65.12% and 25.61 nm, respectively, with a small percentage of other Mn-based oxides within it. The FESEM image showed dice like microsized MnO, revealing the possible formation of a reverse micelle core of approximately 500 nm. XPS narrow spectra revealed the presence of Mn in a mixture of Mn with +2 and +4 oxidation states. The crystal planes from the TEM images matched with XRD results and strengthened the formation of bixbyite MnO nanoparticles. The optical band gap of 3.21 eV specified the semiconducting property of the prepared MnO, and therefore, the prepared MnO was used as a cathode material in a CR-2032 coin cell of ARZIBs. CV showed a reversible reaction within the cell, indicating the (de)intercalation of Zn ions between the anode and cathode. The fresh cell showed high conductivity and low resistance compared with the used cell after BCD testing, confirmed by EIS. The cell delivered high specific discharge capacities of 293.59 ± 4.75 and 252.10 ± 4.66 mA h g at applied current densities of 0.1 and 0.3 A g, respectively. Consequently, BCD was performed for 1000 cycles at a current density of 0.3 A g. Throughout the cycling, the capacity retention and coulombic efficiency were maintained at 90.35 ± 0.30% and 98.44 ± 0.27%, respectively, suggesting the resilient reversibility of charging and discharging.
在本研究中，开发了一种超声辅助反胶束形成，随后通过煅烧路线合成方铁锰矿微片，旨在制造用于水系锌离子电池（ARZIBs）的阴极。制备的产物为MnO，结晶度和晶粒尺寸分别为65.12%和25.61 nm，其中含有少量其他锰基氧化物。场发射扫描电子显微镜（FESEM）图像显示出骰子状的微米级MnO，揭示了可能形成约500 nm的反胶束核。X射线光电子能谱（XPS）窄谱显示存在氧化态为+2和+4的锰的混合物。透射电子显微镜（TEM）图像中的晶面与X射线衍射（XRD）结果相匹配，强化了方铁锰矿MnO纳米颗粒的形成。3.21 eV的光学带隙表明制备的MnO具有半导体性质，因此，制备的MnO被用作水系锌离子电池CR-2032硬币电池的阴极材料。循环伏安法（CV）显示电池内有可逆反应，表明锌离子在阳极和阴极之间的（脱）嵌入。电化学阻抗谱（EIS）证实，与进行恒流充放电（BCD）测试后的使用过的电池相比，新电池具有高导电性和低电阻。在施加的电流密度分别为0.1和0.3 A g时，该电池分别提供了293.59±4.75和252.10±4.66 mA h g的高比放电容量。因此，在0.3 A g的电流密度下进行了1000次恒流充放电循环。在整个循环过程中，容量保持率和库仑效率分别保持在90.35±0.30%和98.44±0.27%，表明充放电具有良好的可逆性。
