Preparation Of Tin-based Nanostructures And Their Lithium Storage Properties

As one kind of n-type semiconductor with a wide band gap of3.6eV, Tin dioxide (SnO2) is an extensively studied material due to its potential application in solar cells, gas sensors, and lithium-ion batteries, and so on. Nano structured tin oxide with unique size and shape may exhibit superior functionality endowed by confining the dimensions of such materials.Novel pompon-like porous SnO2with an average diameter of900run has been successfully synthesized via a simple hydrothermal process with subsequent calcination treatment at600℃for2h in air. The crystalline structure and morphology of the resulting product were characterized by X-ray diffraction, micro-Raman spectrometer, field-emission scanning electron microscopy and transmission electron microscopy. The results indicate that the product is composed of self-assembly SnO2pompon with a high purity tetragonal rutile-like structure. The lithium storage property of the obtained pompon-like porous SnO2was evaluated by conventional discharge/charge test, showing a high initial discharge capacity of1895mAh g-1at a current density of100mA g-1.Porous SnO2-Sn/C composites have been synthesized via directly pyrolysis of mixtures of SnO2powder and poly(vinylidene fluoride) without any surfactant addition and other treatment. The composites are composed of SnO2and Sn nanoparticles which are well encapsulated in porous carbon matrix as characterized by transmission electron microscopy, X-ray powder diffraction and micro-Raman spectrometer. The obtained materials were used as anode for lithium ion batteries, a discharge capacity of1171mA h g-1and a charge capacity of611mA h g-1were shown in the first cycle at a current density of100mA g-1, and good cycling performance achieved even at current density as high as800mA g-1. The good electrochemical behaviors could be attributed to the formation of Sn nanoparticles which can increase the reversible capacity and the porous carbon matrix which is of excellent buffering effect and high electronic conductivity.