Study On Tin-based Nanoparticles And Carbon-Coated Sn Nano-composite For Anode Materials Of Lithium-Ion Battery

As a new anode material for lithium ion battery, Tin-based material which exhibited high theoretical capacity has attracted much attention. However, a major obstacle to the use of tin as an active material is its large volume expansion-contraction that accompanies the lithium alloying-dealloying process. These volume variations result in severing mechanical strains which leads to severe degradation of the anode upon cycling and dramatically shortens the cycle life of the electrode.In the paper, we tried two methods to improve the cycling performance. Firstly, the synthesis of Sn-based material nanoparticle, produced nanoparticle with an average diameter of roughly 7 nm. The method is simpler and has good repeatability. Nanoparticle suffers less absolute volume variations during the lithium alloying-dealloying process, which can relieve the problem of capacity decline. We use that as a lithium-ion battery electrode material, but the cycling stability is not very good, recycling capacity decreased quickly, and need for further improvement.Secondly, the synthesis of carbon- Coated Sn nano-composite was used. We used CVD method to synthesis carbon-coated Sn composite with the SnO₂ nanoparticles as the precursor, and the growth mechanism was investigated. The products have a diameter of about 50 nm, and obtained aspect ratio of up to 300. However, this structure has not been able to improve their electrochemical properties, the second cycle of capacity reached 800mAh / g, but quickly dropped after a few cycles to 200mAh / g. The cycle performance has not been promoted.