Center for Energy Convergence Research, Korea Institute of Science and Technology, Seoul, 136-791, Korea.
Phys Chem Chem Phys. 2015 Sep 28;17(36):23496-502. doi: 10.1039/c5cp03375f.
A ZnO-MnO composite was synthesized using a simple solvothermal method combined with a high-temperature treatment. To observe the phase change during the heating process, in situ high-temperature XRD analysis was performed under vacuum conditions. The results indicated that ZnMn2O4 transformed into the ZnO-MnO composite phase starting from 500 °C and that this composite structure was retained until 700 °C. The electrochemical performances of the ZnO-MnO composite electrode were evaluated through galvanostatic discharge-charge tests and cyclic voltammetry analysis. Its initial coulombic efficiency was significantly improved to 68.3% compared to that of ZnMn2O4 at 54.7%. Furthermore, the ZnO-MnO composite exhibited improved cycling performance and enhanced rate capability compared with untreated ZnMn2O4. To clarify the discharge-charge mechanism of the ZnO-MnO composite electrode, the structural changes during the charge and discharge processes were also investigated using ex situ XRD and TEM.
采用简单的溶剂热法结合高温处理合成了 ZnO-MnO 复合材料。为了观察加热过程中的物相变化，在真空条件下进行了原位高温 X 射线衍射分析。结果表明，ZnMn2O4 从 500°C 开始转化为 ZnO-MnO 复合相，并且这种复合结构一直保持到 700°C。通过恒电流放电-充电测试和循环伏安法分析评估了 ZnO-MnO 复合电极的电化学性能。与 ZnMn2O4 的 54.7%相比，其初始库仑效率显著提高至 68.3%。此外，与未经处理的 ZnMn2O4 相比，ZnO-MnO 复合材料表现出更好的循环性能和增强的倍率性能。为了阐明 ZnO-MnO 复合电极的充放电机制，还使用非原位 XRD 和 TEM 研究了充电和放电过程中的结构变化。
