Zhu Xianyu, Quan Jingbin, Huang Jichun, Ma Zheng, Chen Yixin, Zhu Decheng, Ji Chongxing, Li Decheng
College of Physics, Optoelectronics and Energy, Soochow University Soochow People's Republic of China
RSC Adv. 2018 Feb 15;8(14):7361-7368. doi: 10.1039/c8ra00310f. eCollection 2018 Feb 14.
ZnMnO and Zn Al MnO were synthesized by a spray drying process followed by an annealing treatment. Their structural and electrochemical characteristics were investigated by SEM, XRD, XPS, charge-discharge tests and EIS. XPS data indicate that the substitution of Al for Zn causes manganese to be in a mixed valence state by a charge compensation mechanism. Moreover, the presence of this charge compensation significantly improves the electrochemical performance of Zn Al MnO, such as increasing the initial coulombic efficiency, stabilizing the cycleability as well as improving the rate capability. The sample with 2% Al doping shows the best performance, with a first cycle coulombic efficiency of 69.6% and a reversible capacity of 597.7 mA h g after 100 cycles. Even at the high current density of 1600 mA g, it still retained a capacity of 558 mA h g.
通过喷雾干燥工艺随后进行退火处理合成了ZnMnO和ZnAlMnO。通过扫描电子显微镜（SEM）、X射线衍射（XRD）、X射线光电子能谱（XPS）、充放电测试和电化学阻抗谱（EIS）对它们的结构和电化学特性进行了研究。XPS数据表明，Al取代Zn通过电荷补偿机制使锰处于混合价态。此外，这种电荷补偿的存在显著提高了ZnAlMnO的电化学性能，例如提高初始库仑效率、稳定循环性能以及改善倍率性能。2%Al掺杂的样品表现出最佳性能，首次循环库仑效率为69.6%，100次循环后可逆容量为597.7 mA h g。即使在1600 mA g的高电流密度下，它仍保留558 mA h g的容量。
