Applied Surface Science, Vol.415, 14-18, 2017
Electrochemical properties of Sn/C nanoparticles fabricated by redox treatment and pulsed wire evaporation method
Tin (Sn) based anode materials are the most promising anode materials for lithium-ion batteries due to their high theoretical capacity corresponding to the formation of Li4.4Sn composition (Li4.4Sn, 994 mAh/g). However, the applications of tin based anodes to lithium- ion battery system are generally limited by a large volume change (>260%) during lithiation and delithiation cycle, which causes pulverize and poor cycling stability. In order to overcome this shortcoming, we fabricate a Sn/C nanoparticle with a yolk-shell structure (Sn/void/C) by using pulsed wire evaporation process and oxidation/reduction heat treatment. Sn nanoparticles are encapsulated by a conductive carbon layer with structural buffer that leaves enough room for expansion and contraction during lithium insertion/desertion. We expect that the yolk-shell structure has the ability to accommodate the volume changes of tin and leading to an improved cycle performance. The Sn/Void/C anode with yolk-shell structure shows a high specific capacity of 760 mAh/g after 50 cycles. (C) 2016 Elsevier B.V. All rights reserved.
Keywords:Sn/C nanoparticle;Lithium-ion battery;Pulsed wire evaporation;Core-shell structure;Yolk-shell structure;Redox treatment