Nanosized Li4Ti5O12 powders are synthesized by a polymerization-based method using ti- tanium butoxide and lithium nitrate as precursors and furfuryl alcohol as a polymerizable solvent. The prepared samples are charac...Nanosized Li4Ti5O12 powders are synthesized by a polymerization-based method using ti- tanium butoxide and lithium nitrate as precursors and furfuryl alcohol as a polymerizable solvent. The prepared samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Braunauer-Emmett-Teller （BET） analysis. The electrochemical performances of these Li4Ti5O12 powders are also studied. The effect of different surfactants including citric acid, polyvinylpyrrolidone, and cetyltrimethyl ammonium bromide on the structure and properties is also investigated. It is found that pure spinel phase of Li4Ti5O12 is obtained at an annealing temperature of 700 ℃ or higher. The use of surfactants can improve the powder morphology of nanosized particles with less agglomeration. With suitable annealing temperature and the addition of surfaetant, Li4Ti5O12 powders with high BET surface area and favorable electrochemical performance can be obtained.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
基金V. ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20971117 and No.10979049） and the Education Department of Anhui Province （No.KJ2009A142）.
文摘Nanosized Li4Ti5O12 powders are synthesized by a polymerization-based method using ti- tanium butoxide and lithium nitrate as precursors and furfuryl alcohol as a polymerizable solvent. The prepared samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Braunauer-Emmett-Teller （BET） analysis. The electrochemical performances of these Li4Ti5O12 powders are also studied. The effect of different surfactants including citric acid, polyvinylpyrrolidone, and cetyltrimethyl ammonium bromide on the structure and properties is also investigated. It is found that pure spinel phase of Li4Ti5O12 is obtained at an annealing temperature of 700 ℃ or higher. The use of surfactants can improve the powder morphology of nanosized particles with less agglomeration. With suitable annealing temperature and the addition of surfaetant, Li4Ti5O12 powders with high BET surface area and favorable electrochemical performance can be obtained.
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.
