Sno Tubular Array Of Lithium-ion Battery Anode Material

Lithium-ion batteries are very promising in the markets and electrochemical research field because of their performance: high voltage(generally, the working voltage is about 3.6V), high specific capacity , no memory effect, no pollution , low self-discharge rate and long cycle life. The negative electrode materials is one of the key factors dominating the capacity and cycle life of lithium-ion batteries. The present researches are focused on improving of the qualitative and volumetric capacity , the first charge-discharge efficiency , cycle performance and reducing of the prices of lithium-ion batteries. In this paper, the recent researches and developments on lithium-ion batteries and their anode materials have been reviewed. Tin-oxide is a promising candidate of negative electrode materials for rechargeable lithium-ion batteries because of its high specific capacity.The anode materials based on SnO2 were prepared using the Sol-Gel-Template route. The templates are polycarbonate filtration membranes with different nominal pore diameters.The prepared materials were carefully studied. Crystal structure was characterized by X-ray diffraction(XRD);the configuration was observed by scanning electron miscopy(SEM) and transmission electron microscope(TEM);the component was measured by energy spectrum analysis(EDS);the mass was measured by inductively coupled plasma atomic emission analysis (ICP-AES).These studies indicate that prepared SnO2 electrodes are nano-tubes. They protruded from a current-collector surface like the bristles of a brush.In this paper, the mechanism of intercalation and disintercalation of lithium into tin-oxide material was studied. Cycle performance of nanostructured materials were measured at different current rate. The Li-Sn alloying/dealloying processes were studied in detail via differential specific capacities (dQ/dv).The SnO2 nano-tube structure has larger specific surface area than SnO2 thin-film and have thin wall. Thereby, the depth of incorporation and decorporation of Li ions is superficial and the distance over which Li+ must diffuse in the solid state is dramatically decreased in the nanostructured electrode, eventually, the anode materials based on SnO2 have great mass capacities, good cycle performance and high charge/discharge efficiency. In the galvanostatic discharge/chargeexperiments, the rate capacities and cycle performance of nanostructured SnC>2 at low charge/discharge rates(0.5C and 1C) are obviously better than those at high rate(2C). The charge/discharge efficiency is above 95%. All the tin-oxide material showed a large irreversible capacity for first discharge and exceed even half of the total capacity for first discharge.In this paper, we also compared the charge/discharge performance of nanostructured SnC>2 with different nominal pore diameters. At the beginning, the charge/discharge capacities decreased when the templates' diameters minished, i.e. the relationship of capacities was PC400>PC200>PC50. Whereas, with the charge/discharge processes earring through, the nanostructured SnC>2 prepared by the templates of bigger pore weakened faster than that prepared by the templates of smaller pore, i.e. the capacities of PC400 weakened faster than that PC200 and PC50 .