采用共沉淀-高温固相法制备LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2锂离子正极材料,并使用X射线衍射仪(XRD)和扫描电镜(SEM)技术分别表征其结构和形貌.然后将所得LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2正极材料组装成扣式电池,并表征其电化学性能,探讨...采用共沉淀-高温固相法制备LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2锂离子正极材料,并使用X射线衍射仪(XRD)和扫描电镜(SEM)技术分别表征其结构和形貌.然后将所得LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2正极材料组装成扣式电池,并表征其电化学性能,探讨烧结温度和锂配量对其电化学性能的影响.结果表明:所得LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2正极材料的放电比容量随烧结温度的升高而增大,且在900℃时表现出最佳的电化学性能.室温下,1C倍率下,锂配量(n(Li)/n(Ni+Co+Mn)=1.09)时,正极材料的首次放电容量为143.7 m Ah/g,50次循环后,正极材料的放电比容量仍有141.3 m Ah/g,容量保持率为98.3%.展开更多
采用共沉淀-高温固相法合成正极材料LiNi0．7 Mn0．3 O 2,利用 X 射线衍射分析（XRD）表征其结构、扫描电子显微镜（SEM）表征其形貌、X 射线光电子能谱（XPS）表征其价态,最终确定了该材料最佳烧成温度为820℃.研究表明,该温度下合成的...采用共沉淀-高温固相法合成正极材料LiNi0．7 Mn0．3 O 2,利用 X 射线衍射分析（XRD）表征其结构、扫描电子显微镜（SEM）表征其形貌、X 射线光电子能谱（XPS）表征其价态,最终确定了该材料最佳烧成温度为820℃.研究表明,该温度下合成的 LiNi0．7 Mn0．3 O 2具有典型的α-NaFeO 2型层状结构,颗粒形貌呈类球形且分布均匀；XPS 数据表明,LiNi0．7 Mn0．3 O 2中的 Ni 主要以＋3价形态存在,Mn 主要以＋4价形态存在.室温条件下以0．2 C 倍率在2．75~4．35 V 的电压范围内充放电,首次放电比容量高达188．9 mAh/g,70次循环后容量保持率为95．2％.展开更多
采用化学共沉淀法预先合成球形前驱体Ni0.5Co0.2Mn0.3（OH）2,再与锂源共混后高温煅烧合成高容量正极材料Li Ni0.5Co0.3Mn0.2O2。探讨了不同烧结制度对材料结构性能的影响。X射线衍射（XRD）结果表明,产物结构为α-Na Fe O2型层状结构...采用化学共沉淀法预先合成球形前驱体Ni0.5Co0.2Mn0.3（OH）2,再与锂源共混后高温煅烧合成高容量正极材料Li Ni0.5Co0.3Mn0.2O2。探讨了不同烧结制度对材料结构性能的影响。X射线衍射（XRD）结果表明,产物结构为α-Na Fe O2型层状结构。扫描电子显微镜（SEM）显示材料具有良好的球形形貌。测试材料的电化学性能,在2.75~4.20 V和2.75~4.35 V充放电截止电压,0.5 C充放电电流下,首次放电比容量分别为162.2和172.6 m Ah/g,循环3周后容量保持率分别为96.73%和94.62%。材料还表现出良好的倍率性能。展开更多
LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1（OH）2 at a molar ratio of 1：1.05, followed by sintering at different temperatures. The effects of temperature on th...LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1（OH）2 at a molar ratio of 1：1.05, followed by sintering at different temperatures. The effects of temperature on the morphology, structure and electrochemical performance were extensively studied. SEM and XRD results demonstrate that the sintering temperature has large influence on the morphology and structure and suitable temperature is very important to obtain spherical materials and suppresses the ionic distribution. The charge-discharge tests show that the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 powders becomes better with the increase of temperature from 700 ℃ to 750 ℃ and higher temperature will deteriorate the performance. Although both of materials obtained at 750 ℃ and 780 ℃ demonstrate almost identical cyclic stability at 2C rate, which delivers 71.9%retention after 200 cycles, the rate performance of powder calcined at 780 ℃ is much poorer than that at 750 ℃. The XRD results demonstrate that the poor performance is ascribed to more severe ionic distribution caused by higher temperature.展开更多
文摘采用共沉淀-高温固相法制备LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2锂离子正极材料,并使用X射线衍射仪(XRD)和扫描电镜(SEM)技术分别表征其结构和形貌.然后将所得LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2正极材料组装成扣式电池,并表征其电化学性能,探讨烧结温度和锂配量对其电化学性能的影响.结果表明:所得LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2正极材料的放电比容量随烧结温度的升高而增大,且在900℃时表现出最佳的电化学性能.室温下,1C倍率下,锂配量(n(Li)/n(Ni+Co+Mn)=1.09)时,正极材料的首次放电容量为143.7 m Ah/g,50次循环后,正极材料的放电比容量仍有141.3 m Ah/g,容量保持率为98.3%.
文摘采用共沉淀-高温固相法合成正极材料LiNi0．7 Mn0．3 O 2,利用 X 射线衍射分析（XRD）表征其结构、扫描电子显微镜（SEM）表征其形貌、X 射线光电子能谱（XPS）表征其价态,最终确定了该材料最佳烧成温度为820℃.研究表明,该温度下合成的 LiNi0．7 Mn0．3 O 2具有典型的α-NaFeO 2型层状结构,颗粒形貌呈类球形且分布均匀；XPS 数据表明,LiNi0．7 Mn0．3 O 2中的 Ni 主要以＋3价形态存在,Mn 主要以＋4价形态存在.室温条件下以0．2 C 倍率在2．75~4．35 V 的电压范围内充放电,首次放电比容量高达188．9 mAh/g,70次循环后容量保持率为95．2％.
文摘采用化学共沉淀法预先合成球形前驱体Ni0.5Co0.2Mn0.3（OH）2,再与锂源共混后高温煅烧合成高容量正极材料Li Ni0.5Co0.3Mn0.2O2。探讨了不同烧结制度对材料结构性能的影响。X射线衍射（XRD）结果表明,产物结构为α-Na Fe O2型层状结构。扫描电子显微镜（SEM）显示材料具有良好的球形形貌。测试材料的电化学性能,在2.75~4.20 V和2.75~4.35 V充放电截止电压,0.5 C充放电电流下,首次放电比容量分别为162.2和172.6 m Ah/g,循环3周后容量保持率分别为96.73%和94.62%。材料还表现出良好的倍率性能。
基金Project(2014CB643406)supported by the National Basic Research Program of China
文摘LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1（OH）2 at a molar ratio of 1：1.05, followed by sintering at different temperatures. The effects of temperature on the morphology, structure and electrochemical performance were extensively studied. SEM and XRD results demonstrate that the sintering temperature has large influence on the morphology and structure and suitable temperature is very important to obtain spherical materials and suppresses the ionic distribution. The charge-discharge tests show that the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 powders becomes better with the increase of temperature from 700 ℃ to 750 ℃ and higher temperature will deteriorate the performance. Although both of materials obtained at 750 ℃ and 780 ℃ demonstrate almost identical cyclic stability at 2C rate, which delivers 71.9%retention after 200 cycles, the rate performance of powder calcined at 780 ℃ is much poorer than that at 750 ℃. The XRD results demonstrate that the poor performance is ascribed to more severe ionic distribution caused by higher temperature.
