The Study Of Anode Materials Based On Tin Oxide

Rechargeable lithium-ion battery has the best applying prospect in thebattery market. The property of battery is decided greatly by choosing theoptimal anode materials. Now the commercial carbon anode material can'tmeet the needs of the consumers for large capacity, so a lot of researcheshas focused on finding new large capacity anode material candidates. In this paper, the anode materials based on SnO2 were prepared usingthe Sol-Gel technique, and were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM), Transmission Electron Microscope(TEM), the Brunauer, Emmett, Teller (BET), TG-DTA ,and elementanalysis. In the end, they were used as the anode materials of thelithium-ion battery, and their electrochemical performance were studied indetail. Our work was shown as the following: 1. Here we got the SnO2 round particles with 40 nm diameter bySol-Gel technique. When it was used as the anode material for lithim-ionbattery, in the first cycle it shown a large dishcharge reversible capacity of710mAh/g, which is two times that of graphite. And it also has a largeirreversible capacity of 662 mAh/g , almost 48.3 % of the first total chargecapacity. The capacity reducing very fast in the cycles shows the poorcyclability of the material. 2. The tin oxide with different carbon contents, surface morphologiesand specific surface areas were obtained by firing the precursor underdifferent treatment temperatures with Sol-gel technique, and their differentelectrochemical performance corresponding well with their characteristic.We firstly obtained the relationship between the electrochemicalperformance of the tin oxide anode material and its component, particlesize, structure and surface morphology in detail. It was found that the best iii东北师范大学硕士学位论文electrochemical performance can be reached by controlling the physicalcharacteristics of SnO2, which was affected greatly by the treatmenttemperature. 3. To improve the cyclability of SnO2 anode material, prevent theaggregation of Sn particle during the cycling, here we chose graphite to bethe dispersant in the system, prepared the composite of SnO2/graphitewith Sol-gel technique. This composite shows a improved cyclabilitycompared with that of the pure SnO2. When the composite was treatedunder a suitable higher temperature, both the cyclability and the capacityproperty will go on to improve. 4. Here we also use carbon nanotube (CNT) to be the dispersant ofSnO2. We found the SnO2/CNT composite obtained using the Sol-Geltechnique has changed its morphologies greatly compared with that of thepure SnO2 and CNT, with the doping of CNT, the particle size of SnO2 ismuch smaller, and hence has effect on its cyclability . Here we found boththe capacity property and the cyclability of the composite are better thanthat of the pure SnO2.