通过简单的湿法球磨混合工艺,经过低温热处理得到Co3O4修饰Li4Ti5O12复合材料。通过X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)、能量散射光谱(EDS)、恒电流充放电测试、循环伏安(CV)以及交流阻抗(EIS)对材料的结构、形貌、组成及电...通过简单的湿法球磨混合工艺,经过低温热处理得到Co3O4修饰Li4Ti5O12复合材料。通过X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)、能量散射光谱(EDS)、恒电流充放电测试、循环伏安(CV)以及交流阻抗(EIS)对材料的结构、形貌、组成及电化学性能进行表征。结果表明,Co3O4修饰没有改变Li4Ti5O12的尖晶石结构,以小颗粒的形式分布在材料中。Co3O4修饰增强了材料的电化学活性,减小了电极极化,使得材料的电化学性能得到提高。其中1%(质量分数)的Co3O4修饰Li4Ti5O12显示出较好的倍率性能和循环稳定性,0.2 C下的首次放电比容量为174 m Ah/g,2 C下循环300次后比容量为128.2 m Ah/g,容量保持率为95.6%。展开更多
Li[Li1/3Ti5/3O4] spinel-framework structure material is a kind of great interest for negative electrodes in energy storage cell. The synthesis of nanocrystalline Li[Li1/3Ti5/3O4] by sol-gel method using inorganic comp...Li[Li1/3Ti5/3O4] spinel-framework structure material is a kind of great interest for negative electrodes in energy storage cell. The synthesis of nanocrystalline Li[Li1/3Ti5/3O4] by sol-gel method using inorganic compounds and citric acid is developed, and single phase powder is obtained above 700 ℃. The electrochemical performances (of Li[Li1/3Ti5/3O4]) cathodes in lithium cell are studied. Special capacities are 131 mA·h·g-1 at 0.5C rate and 154 mA·h·g-1 at 0.1C in cycle test. No passivation layer is formed on Li[Li1/3Ti5/3O4] anode in lithium ion battery, and it is much safer than lithium metal and carbonaceous anodes. Faradic impedance in the charged cell is remarkably higher than that in discharged state, which is caused by distinct conductivities of Li[Li1/3Ti5/3O4] and (Li2[Li1/3Ti5/3O4].)展开更多
The pure Cr2O3 coated Li4Ti5O12 microspheres were prepared by a facile and cheap solution- based method with basic chromium（III） nitrate solution （pH=ll.9）. And their Li-storage properties were investigated as ano...The pure Cr2O3 coated Li4Ti5O12 microspheres were prepared by a facile and cheap solution- based method with basic chromium（III） nitrate solution （pH=ll.9）. And their Li-storage properties were investigated as anode materials for lithium rechargeable batteries. The pure Cr2O3 works as an adhesive interface to strengthen the connections between Li4Ti5O12 par- ticles, providing more electric conduction channels, and reduce the inter-particle resistance. Moreover, Li2Cr2O3, formed by the lithiation of Cr2O3, can further stabilize LiTTi5O12 with high electric conductivity on the surface of particles. While in the acid chromium solution （pH=3.2） modification, besides Cr2O3, Li2CrO4 and TiO2 phases were also found in the final product. Li2CrO4 is toxic and the presence of TiO2 is not welcome to im- prove the electrochemical performance of Li4Ti5O12 microspheres. The reversible capacity of 1% Cr2O3-coated sample with the basic chromium solution modification was 180 mAh/g at 0.1 C, and 134 mAh/g at 10 C. Moreover, it was even as high as 127 mAh/g at 5 C after 600 cycles. At -20 ℃, its reversible specific capacity was still as high as 118 mAh/g.展开更多
采用溶胶凝胶法制备Li4-x/3FexTi5-2x/3O12(x=0,0.03,0.06,0.09)粉体活性材料,并优化了最佳掺杂量为x=0.03。通过X射线衍射(XRD)、扫描电镜(SEM)、恒流充放电测试对材料进行结构、形貌及电化学性能表征。结果表明:掺杂适量的铁离子不会...采用溶胶凝胶法制备Li4-x/3FexTi5-2x/3O12(x=0,0.03,0.06,0.09)粉体活性材料,并优化了最佳掺杂量为x=0.03。通过X射线衍射(XRD)、扫描电镜(SEM)、恒流充放电测试对材料进行结构、形貌及电化学性能表征。结果表明:掺杂适量的铁离子不会改变钛酸锂的尖晶石结构和形貌。1C时,Li3.99Fe0.03Ti4.98O12首次放电比容量为145.40 m A·h/g;纯相的首次放电比容量仅为116.95 m A·h/g。展开更多
文摘通过简单的湿法球磨混合工艺,经过低温热处理得到Co3O4修饰Li4Ti5O12复合材料。通过X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)、能量散射光谱(EDS)、恒电流充放电测试、循环伏安(CV)以及交流阻抗(EIS)对材料的结构、形貌、组成及电化学性能进行表征。结果表明,Co3O4修饰没有改变Li4Ti5O12的尖晶石结构,以小颗粒的形式分布在材料中。Co3O4修饰增强了材料的电化学活性,减小了电极极化,使得材料的电化学性能得到提高。其中1%(质量分数)的Co3O4修饰Li4Ti5O12显示出较好的倍率性能和循环稳定性,0.2 C下的首次放电比容量为174 m Ah/g,2 C下循环300次后比容量为128.2 m Ah/g,容量保持率为95.6%。
文摘Li[Li1/3Ti5/3O4] spinel-framework structure material is a kind of great interest for negative electrodes in energy storage cell. The synthesis of nanocrystalline Li[Li1/3Ti5/3O4] by sol-gel method using inorganic compounds and citric acid is developed, and single phase powder is obtained above 700 ℃. The electrochemical performances (of Li[Li1/3Ti5/3O4]) cathodes in lithium cell are studied. Special capacities are 131 mA·h·g-1 at 0.5C rate and 154 mA·h·g-1 at 0.1C in cycle test. No passivation layer is formed on Li[Li1/3Ti5/3O4] anode in lithium ion battery, and it is much safer than lithium metal and carbonaceous anodes. Faradic impedance in the charged cell is remarkably higher than that in discharged state, which is caused by distinct conductivities of Li[Li1/3Ti5/3O4] and (Li2[Li1/3Ti5/3O4].)
基金This work was supported by the National Natural Science Foundation of China （No.51372060 and No.31501576）.
文摘The pure Cr2O3 coated Li4Ti5O12 microspheres were prepared by a facile and cheap solution- based method with basic chromium（III） nitrate solution （pH=ll.9）. And their Li-storage properties were investigated as anode materials for lithium rechargeable batteries. The pure Cr2O3 works as an adhesive interface to strengthen the connections between Li4Ti5O12 par- ticles, providing more electric conduction channels, and reduce the inter-particle resistance. Moreover, Li2Cr2O3, formed by the lithiation of Cr2O3, can further stabilize LiTTi5O12 with high electric conductivity on the surface of particles. While in the acid chromium solution （pH=3.2） modification, besides Cr2O3, Li2CrO4 and TiO2 phases were also found in the final product. Li2CrO4 is toxic and the presence of TiO2 is not welcome to im- prove the electrochemical performance of Li4Ti5O12 microspheres. The reversible capacity of 1% Cr2O3-coated sample with the basic chromium solution modification was 180 mAh/g at 0.1 C, and 134 mAh/g at 10 C. Moreover, it was even as high as 127 mAh/g at 5 C after 600 cycles. At -20 ℃, its reversible specific capacity was still as high as 118 mAh/g.
文摘采用溶胶凝胶法制备Li4-x/3FexTi5-2x/3O12(x=0,0.03,0.06,0.09)粉体活性材料,并优化了最佳掺杂量为x=0.03。通过X射线衍射(XRD)、扫描电镜(SEM)、恒流充放电测试对材料进行结构、形貌及电化学性能表征。结果表明:掺杂适量的铁离子不会改变钛酸锂的尖晶石结构和形貌。1C时,Li3.99Fe0.03Ti4.98O12首次放电比容量为145.40 m A·h/g;纯相的首次放电比容量仅为116.95 m A·h/g。
