采用高温固相法烧结制备得到正极材料Li Ni0.5Co0.2Mn0.3O2,通过X射线衍射(XRD)、扫描电镜(SEM)以及循环伏安(CV)、交流阻抗(EIS)等电化学性能测试手段,探讨高温烧结工艺中不同锂源对材料结构、形貌及电化学性能的影响,结果表明,采用Li...采用高温固相法烧结制备得到正极材料Li Ni0.5Co0.2Mn0.3O2,通过X射线衍射(XRD)、扫描电镜(SEM)以及循环伏安(CV)、交流阻抗(EIS)等电化学性能测试手段,探讨高温烧结工艺中不同锂源对材料结构、形貌及电化学性能的影响,结果表明,采用Li OH作为锂源合成的材料与采用其他锂源相比,具有较好的层状结构和电化学性能.该材料在0.1C倍率下的首次充放电容量和库伦效率较高(172.7 m Ah/g,89.08%),在0.5C、1C倍率下循环50次后,材料的放电容量仍保持在144.5 m Ah/g和136.2 m Ah/g.展开更多
LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysi...LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysis was applied to investigating the mixture of transition metal acetates. X-ray powder diffraction and charge–discharge test were adopted to characterize the as-prepared LiNi0.8Co0.1Mn0.1O2. The mixture of transition metal acetates undergoes dehydration and decomposition during heating. All the examined LiNi0.8Co0.1Mn0.1O2 samples have a layered structure with R3 m space group. LiNi0.8Co0.1Mn0.1O2 samples prepared with different lithium sources under different synthesis conditions exhibit very different charge–discharge performances. The sample synthesized via the procedure of sintering at 800 °C after heating lithium carbonate and transition metal acetates at 550 °C achieves a highest capacity of 200.8 m A·h/g and an average capacity of 188.1 mA ·h/g in the first 20 cycles at 0.2C.展开更多
文摘采用高温固相法烧结制备得到正极材料Li Ni0.5Co0.2Mn0.3O2,通过X射线衍射(XRD)、扫描电镜(SEM)以及循环伏安(CV)、交流阻抗(EIS)等电化学性能测试手段,探讨高温烧结工艺中不同锂源对材料结构、形貌及电化学性能的影响,结果表明,采用Li OH作为锂源合成的材料与采用其他锂源相比,具有较好的层状结构和电化学性能.该材料在0.1C倍率下的首次充放电容量和库伦效率较高(172.7 m Ah/g,89.08%),在0.5C、1C倍率下循环50次后,材料的放电容量仍保持在144.5 m Ah/g和136.2 m Ah/g.
基金Project(2010ZC051)supported by the Natural Science Foundation of Yunnan Province,ChinaProject(20140439)supported by the Analysis and Testing Foundation from Kunming University of Science and Technology,ChinaProject(14118245)supported by the Starting Research Fund from Kunming University of Science and Technology,China
文摘LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysis was applied to investigating the mixture of transition metal acetates. X-ray powder diffraction and charge–discharge test were adopted to characterize the as-prepared LiNi0.8Co0.1Mn0.1O2. The mixture of transition metal acetates undergoes dehydration and decomposition during heating. All the examined LiNi0.8Co0.1Mn0.1O2 samples have a layered structure with R3 m space group. LiNi0.8Co0.1Mn0.1O2 samples prepared with different lithium sources under different synthesis conditions exhibit very different charge–discharge performances. The sample synthesized via the procedure of sintering at 800 °C after heating lithium carbonate and transition metal acetates at 550 °C achieves a highest capacity of 200.8 m A·h/g and an average capacity of 188.1 mA ·h/g in the first 20 cycles at 0.2C.
文摘采用Li_2CO_3与Li OH·H_2O为复合锂源制备LiFePO_4/C材料,同时优化了材料中的碳含量。由于氢氧化锂的熔点低于碳酸锂,在同样的烧结温度下,采用复合锂源可以获得更佳的熔融状态,在高温合成过程中使锂离子具有更高的扩散性,能够更顺利地得到高纯度的LiFePO_4晶相。通过优化碳包覆量达到提高导电性与控制晶粒尺寸的目的,使材料晶相结构完整,纯度高,表现出优秀的加工性能与电化学性能。所制得的LiFePO_4/C材料放电克容量达到158.2 m Ah·g^(-1),在全电池中经过100 d存储后容量保持率仍然高于94.0%,具有优异的长期可靠性。
