A chemical deposition was supposed to be an effwient method in preparation of nano-sized Sn/ MWNTs. The nanoconmposites of MWNTs and Sn/ MWNTs were both used as anodes of lithium ion battery. The special capacities an...A chemical deposition was supposed to be an effwient method in preparation of nano-sized Sn/ MWNTs. The nanoconmposites of MWNTs and Sn/ MWNTs were both used as anodes of lithium ion battery. The special capacities and coulomb efficiencies of Snl MWNTs were studied by means of electrochemical methods. The coating of Sn on MWNTs observed by TEM was amorphous and nano-sized. The reversible capacity of Sn/ MWNTs , which was much larger than that of MWNTs , was 824 mAh/ g in the 1 st charge and discharge cycle. The coulomb efficiency of Sn/ MWNTs in the 1 st cycle was increased by 16% compared with that of MWNTs. The additional Sn, which was 37wt% of total Sn/ MWNTs＇ weight, introduced the additional reversible lithiation capacity at least 250 mAh/ g in the 40 charge and discharge cycles. The dispersing degree of Sn on MWNTs was the main reason for the influence of the electrochemical perfomance of the Sn/ MWNTs . Sn/ MWNTs is proved to be a promising candidate as an anode of lithium ion battery.展开更多
The raw carbon nanotubes (CNTs) prepared by chemical vapor deposition (CVD) were used in electrochemical lithiation. To remove the impurity the mild oxidation was done on the samples. The electrochemical characteristi...The raw carbon nanotubes (CNTs) prepared by chemical vapor deposition (CVD) were used in electrochemical lithiation. To remove the impurity the mild oxidation was done on the samples. The electrochemical characteristics of the two samples are investigated by the galvanostatic charge-discharge measurements and cyclic voltammetry. The structural and interfacial changes of the CNTs electrode were analyzed by XRD and FT-IR. The samples show a reversibility of lithium intercalation and de-intercalation. The reversible capacities of the first five cycles are larger than 300 mAh/g and the irreversible capacity of the first cycle was much larger than that mentioned in literatures. There is no identical change in the structure during the charge and discharge. The reactions at the interface between electrode and the electrolyte are similar to those of other carbonaceous materials.展开更多
A tin oxide and carbon composite （Sn6O4（OH）4/AG） with a Sn content of 0.15-0.30 was prepared by chemical deposition at normal pressures and temperatures. The structures of the artificial graphite （AG）, the Sn6O4...A tin oxide and carbon composite （Sn6O4（OH）4/AG） with a Sn content of 0.15-0.30 was prepared by chemical deposition at normal pressures and temperatures. The structures of the artificial graphite （AG）, the Sn6O4（OH）4, and the Sn6O4（OH）4JAG were analyzed using X-ray diffraction. The electrochemical lithiation was investigated by measuring the galvanostatic charge and discharge ratio. The electrochemical capacities of the three materials during the first discharge were 310 mAh/g （AG）, 616 mAh/g （Sn6O4（OH）4/AG）, and 1090 mAh/g （Sn6O4（oa）4）. The discharge capacity of the Sn6O4（OH）4/AG was larger than the simple sum of the capacities provided by AG and Sn6O4（OH）4 with the same content. The cyclic performance of Sn6O4（OH）4/AG was also better than that of Sn6O4（OH）4 for voltages of 0 to 3 V. The results imply that the interaction between Sn and C in Sn6O4（OH）4/AG is very strong and effectively inhibits the volume expansion of the Sn.展开更多
基金Funded by the National Basic Research Programof China( No.2003CB61570)
文摘A chemical deposition was supposed to be an effwient method in preparation of nano-sized Sn/ MWNTs. The nanoconmposites of MWNTs and Sn/ MWNTs were both used as anodes of lithium ion battery. The special capacities and coulomb efficiencies of Snl MWNTs were studied by means of electrochemical methods. The coating of Sn on MWNTs observed by TEM was amorphous and nano-sized. The reversible capacity of Sn/ MWNTs , which was much larger than that of MWNTs , was 824 mAh/ g in the 1 st charge and discharge cycle. The coulomb efficiency of Sn/ MWNTs in the 1 st cycle was increased by 16% compared with that of MWNTs. The additional Sn, which was 37wt% of total Sn/ MWNTs＇ weight, introduced the additional reversible lithiation capacity at least 250 mAh/ g in the 40 charge and discharge cycles. The dispersing degree of Sn on MWNTs was the main reason for the influence of the electrochemical perfomance of the Sn/ MWNTs . Sn/ MWNTs is proved to be a promising candidate as an anode of lithium ion battery.
文摘The raw carbon nanotubes (CNTs) prepared by chemical vapor deposition (CVD) were used in electrochemical lithiation. To remove the impurity the mild oxidation was done on the samples. The electrochemical characteristics of the two samples are investigated by the galvanostatic charge-discharge measurements and cyclic voltammetry. The structural and interfacial changes of the CNTs electrode were analyzed by XRD and FT-IR. The samples show a reversibility of lithium intercalation and de-intercalation. The reversible capacities of the first five cycles are larger than 300 mAh/g and the irreversible capacity of the first cycle was much larger than that mentioned in literatures. There is no identical change in the structure during the charge and discharge. The reactions at the interface between electrode and the electrolyte are similar to those of other carbonaceous materials.
文摘A tin oxide and carbon composite （Sn6O4（OH）4/AG） with a Sn content of 0.15-0.30 was prepared by chemical deposition at normal pressures and temperatures. The structures of the artificial graphite （AG）, the Sn6O4（OH）4, and the Sn6O4（OH）4JAG were analyzed using X-ray diffraction. The electrochemical lithiation was investigated by measuring the galvanostatic charge and discharge ratio. The electrochemical capacities of the three materials during the first discharge were 310 mAh/g （AG）, 616 mAh/g （Sn6O4（OH）4/AG）, and 1090 mAh/g （Sn6O4（oa）4）. The discharge capacity of the Sn6O4（OH）4/AG was larger than the simple sum of the capacities provided by AG and Sn6O4（OH）4 with the same content. The cyclic performance of Sn6O4（OH）4/AG was also better than that of Sn6O4（OH）4 for voltages of 0 to 3 V. The results imply that the interaction between Sn and C in Sn6O4（OH）4/AG is very strong and effectively inhibits the volume expansion of the Sn.
