Li4Ti5O12 was synthesized by a facile gel-combustion method（GCM） with polyvinylpyrrolidone（PVP） as the polymer chelating agent and fuel.The structural and electrochemical properties of the sample were compared wit...Li4Ti5O12 was synthesized by a facile gel-combustion method（GCM） with polyvinylpyrrolidone（PVP） as the polymer chelating agent and fuel.The structural and electrochemical properties of the sample were compared with the one prepared by the conventional solid-state reaction（SSR） through X-ray diffraction（XRD）,scanning electron microscopy（SEM）,cyclic voltammetry（CV）,charge-discharge measurements,and electrochemical impedance spectroscopy（EIS）,respectively.The sub-microscale Li4Ti5O12 oxides,with a high phase purity and good stoichiometry,can be obtained by annealing at 800℃.The grain size is smaller than that of the samples that were power prepared by SSR.Lithium-ion batteries with a GCM Li4Ti5O12 anode exhibit excellent reversible capacities of 167.6,160.7,152.9,and 144.2 mAh/g,at the current densities of 0.5 C,1 C,3 C and 5 C,respectively.The excellent cycling and rate performance can be attributed to the smaller particle size,lower charge-transfer resistance and larger lithium ion diffusion coefficient.It is therefore concluded that GCM Li4Ti5O12 is a promising candidate for applications in highrate lithium ion batteries.展开更多
基金supported by the National Natural Science Foundation of China(No.51374056)the support program for hundreds of outstanding innovative talents in Higher Education Institutions of Hebei Province(Ⅱ)(No.BR2-127)+2 种基金Natural Science Foundation of Hebei Province(No.E2013501135)program for New Century Excellent Talents in University(No.NCET-10-0304)The Special Fund for Basic Scientific Research of Central Colleges, Northeastern University(Nos.N100123003 and N120523001)
文摘Li4Ti5O12 was synthesized by a facile gel-combustion method（GCM） with polyvinylpyrrolidone（PVP） as the polymer chelating agent and fuel.The structural and electrochemical properties of the sample were compared with the one prepared by the conventional solid-state reaction（SSR） through X-ray diffraction（XRD）,scanning electron microscopy（SEM）,cyclic voltammetry（CV）,charge-discharge measurements,and electrochemical impedance spectroscopy（EIS）,respectively.The sub-microscale Li4Ti5O12 oxides,with a high phase purity and good stoichiometry,can be obtained by annealing at 800℃.The grain size is smaller than that of the samples that were power prepared by SSR.Lithium-ion batteries with a GCM Li4Ti5O12 anode exhibit excellent reversible capacities of 167.6,160.7,152.9,and 144.2 mAh/g,at the current densities of 0.5 C,1 C,3 C and 5 C,respectively.The excellent cycling and rate performance can be attributed to the smaller particle size,lower charge-transfer resistance and larger lithium ion diffusion coefficient.It is therefore concluded that GCM Li4Ti5O12 is a promising candidate for applications in highrate lithium ion batteries.
