中文摘要：

以废旧锂离子电池LiMn2O4正极材料为原料,通过控制酸浸条件分别制备出λ-MnO2纳米粒子和β-MnO2纳米棒,研究作为一次电池电极材料和超级电容器电极材料的相关电化学性能。利用X射线粉末衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和恒电流充放电、循环伏安等测试手段对样品成分、形貌和电化学性能进行分析表征。实验表明：在常温常压下,采用0.5mol.L-1的H2SO4酸浸3h可制备出λ-MnO2纳米颗粒;而于140℃水热条件下,采用2mol.L-1的H2SO4酸浸24h可制得β-MnO2纳米棒。λ-MnO2纳米颗粒和β-MnO2纳米棒作为Li/MnO2一次电池电极材料的放电比容量分别为142mA.h.g-1和275mA.h.g-1,而市售β-MnO2放电比容量为163mA.h.g-1。此外,作为对称型超级电容器的电极材料也表现出较好的超级电容特性,在1mol.L-1的Na2SO4电解液中,λ-MnO2和β-MnO2的恒流充放电比电容分别为87.4F.g-1和85.7F.g-1,高于市售β-MnO2的恒流充放电比电容（76.1F.g-1）。

英文摘要：

λ-MnO2 nanoparticles and β-MNO2 nanorods were successfully prepared from spent LiMn2O4 cathode materials by controlling appropriate leaching conditions in this study. Their electrochemical properties were investigated as electrode materials for primary cells and supercapacitors. The composition, morphology and electrochemical properties of the obtained samples were characterized by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, constant current charge-discharge and cyclic voltammetry measurements. The results indicated that λ-MnO2 nanoparticles could be prepared at ambient temperature and pressure, with 0.5 mol . L -1 H2 SO4 leaching the spent LiMn204 for 3 h, and β-MnO2 nanorods could be synthesized under hydrothermal conditions of 140℃, with 2 mol . L-1 H2SO4 leaching the spent LiMn2O4 for 24 h. The λ-MnO2 and β-MnO2 samples delivered discharge capacities of 142 mA . h . g- 1 and 275 mA . h . g -1 , respectively as electrode materials for Li/MnOa primary cells, while the commercial β-MnO2 only delivered a discharge capacity of 163 mA.h.g-1. Both of the λ-MnO2 and β-MnO2 samples as electrode materials for supercapacitors exhibited good capacitance property, with specific capacitance of 87.4 F . g -1 and 85.7 F . g-1 , respectively in 1 mol . L-1 Na2SO4 electrolyte solution, while the commercial 13-MnO2 only presented a specific capacitance of76. 1 F. g-1.