研究了不同烧结温度及恒温保持时间对富锂锰基正极材料Li1＋x[Ni0.35Mn0.65]O2＋y形貌、结构及电化学性能的影响。XRD及SEM研究结果表明：所合成的Li1＋x[Ni0.35Mn0.65]O2＋y正极材料为层状α-NaFeO2结构,类球形,单颗粒大小均匀。扣式...研究了不同烧结温度及恒温保持时间对富锂锰基正极材料Li1＋x[Ni0.35Mn0.65]O2＋y形貌、结构及电化学性能的影响。XRD及SEM研究结果表明：所合成的Li1＋x[Ni0.35Mn0.65]O2＋y正极材料为层状α-NaFeO2结构,类球形,单颗粒大小均匀。扣式电池测试结果表明：当电流密度为12.5 m A/g,测试电压在2.04.8 V时,Li1＋x[Ni0.35Mn0.65]O2＋y材料最高初始放电比容量为213.3 m A·h/g,首次放电效率为71.0%。扣电进行EIS测试,结果表明材料具有较小的电荷转移阻抗。展开更多
采用高温固相法合成Li1＋x[Ni0.35Mn0.65]O2（x=0.35、0.40、0.45和0.50）富锂锰基正极材料,进行XRD、SEM、电化学阻抗谱（EIS）分析和电化学性能测试。所得材料具有α-NaFeO2层状结构,一次颗粒为类球形,平均粒径约为500 nm,最佳x值为0...采用高温固相法合成Li1＋x[Ni0.35Mn0.65]O2（x=0.35、0.40、0.45和0.50）富锂锰基正极材料,进行XRD、SEM、电化学阻抗谱（EIS）分析和电化学性能测试。所得材料具有α-NaFeO2层状结构,一次颗粒为类球形,平均粒径约为500 nm,最佳x值为0.45。x=0.45的材料于25℃时在2.04.8 V充放电,0.05 C首次放电比容量和首次循环的库仑效率分别为227.7 m Ah/g和71.7%,1.00 C最高放电比容量为182.6 m Ah/g。EIS测试表明：材料组装的电池的电荷转移阻抗较低。展开更多
A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary...A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary phase including SrxCa1-xTiO3(0≤x≤1)solid solution and TiO2 co-exist in composite and form a stable composite system when the(CaxSr1-x)(0≤x≤1)substitutes for Zn of Li2ZnTi3O8 ceramic.As x is increased from 0 to 1,the relative permittivity(εr)increases from 26.65 to 27.12,and the quality factor(Q×f)increases from 63300 to 66600 GHz.With the increased of x,the temperature coefficient of resonant frequency(τf)increases from 0.27 to 8.23 ppm/℃,and then decreases to 3.51 ppm/℃.On the whole,the Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics show excellent comprehensive properties of middleεr=25-27,higher Q×f≥60000 GHz andτf≤±8.5 ppm/℃.展开更多
Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, sha...Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, shape, and ionic conductivity of these samples. The results show that the range of solid solution formation is in 0< x ≤0 09, in which the conductivity of these samples raises with the increasing amount of RE 2O 3 (RE=Pr, Nd, Sm, Gd) added, and the diameter of the powders is about 100 nm. Compared with the conventional solid state reaction, the sol gel method needs low temperature and presents high ionic conductivity.展开更多
文摘研究了不同烧结温度及恒温保持时间对富锂锰基正极材料Li1＋x[Ni0.35Mn0.65]O2＋y形貌、结构及电化学性能的影响。XRD及SEM研究结果表明：所合成的Li1＋x[Ni0.35Mn0.65]O2＋y正极材料为层状α-NaFeO2结构,类球形,单颗粒大小均匀。扣式电池测试结果表明：当电流密度为12.5 m A/g,测试电压在2.04.8 V时,Li1＋x[Ni0.35Mn0.65]O2＋y材料最高初始放电比容量为213.3 m A·h/g,首次放电效率为71.0%。扣电进行EIS测试,结果表明材料具有较小的电荷转移阻抗。
文摘采用高温固相法合成Li1＋x[Ni0.35Mn0.65]O2（x=0.35、0.40、0.45和0.50）富锂锰基正极材料,进行XRD、SEM、电化学阻抗谱（EIS）分析和电化学性能测试。所得材料具有α-NaFeO2层状结构,一次颗粒为类球形,平均粒径约为500 nm,最佳x值为0.45。x=0.45的材料于25℃时在2.04.8 V充放电,0.05 C首次放电比容量和首次循环的库仑效率分别为227.7 m Ah/g和71.7%,1.00 C最高放电比容量为182.6 m Ah/g。EIS测试表明：材料组装的电池的电荷转移阻抗较低。
基金Funded by the Open Project Program of Key Laboratory of Inorganic Functional Materials and Devices,Chinese Academy of Sciences(No.KLIFMD201606)the Open Fund of National Innovation Platform(No.2017YJ163)+1 种基金the National Natural Science Foundation of China(Nos.51502220,51521001,and 51672197)the Open Foundation of Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics(Wuhan University of Technology)(No.TAM201802)。
文摘A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary phase including SrxCa1-xTiO3(0≤x≤1)solid solution and TiO2 co-exist in composite and form a stable composite system when the(CaxSr1-x)(0≤x≤1)substitutes for Zn of Li2ZnTi3O8 ceramic.As x is increased from 0 to 1,the relative permittivity(εr)increases from 26.65 to 27.12,and the quality factor(Q×f)increases from 63300 to 66600 GHz.With the increased of x,the temperature coefficient of resonant frequency(τf)increases from 0.27 to 8.23 ppm/℃,and then decreases to 3.51 ppm/℃.On the whole,the Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics show excellent comprehensive properties of middleεr=25-27,higher Q×f≥60000 GHz andτf≤±8.5 ppm/℃.
文摘Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, shape, and ionic conductivity of these samples. The results show that the range of solid solution formation is in 0< x ≤0 09, in which the conductivity of these samples raises with the increasing amount of RE 2O 3 (RE=Pr, Nd, Sm, Gd) added, and the diameter of the powders is about 100 nm. Compared with the conventional solid state reaction, the sol gel method needs low temperature and presents high ionic conductivity.
