Improved Li storage performance of SnO nanodisc on SnO2 quantum dots embedded carbon matrix

Abstract

Li-ion batteries with conversion type anode are attractive choice, for electric vehicles and portable electronic devices, because of their high theoretical capacity and cycle stability. On the contrary, enormous volume change during lithiation/delithiation and irreversible conversion reaction limits use of such anodes. To overcome these challenges, incorporating nano-sized SnO x on flexible carbonaceous matrix is an efficient approach. A facile and scalable fabrication of SnO nanodisc decorated on SnO2 quantum dots embedded carbon (SnO x @C) is reported in the present study. Detailed structural and morphological investigation confirms the successful synthesis of SnO x @C composite with 72.3 wt% SnO x loading. The CV profiles of the nanocomposite reveal a partial reversibility of conversion reaction for the active materials SnO x . Such partial reversible conversion enhances the overall capacity of the nanocomposite. It delivers a very high discharge capacity of 993 mAh g−1 at current density of 0.05 A g−1 after 200 cycles; which is 2.6 times higher than that of commercial graphitic anode (372 mAh g−1) and very close to the calculated capacity of the SnO x @C composite. This unique nanocomposite remarkably improves Li storage performance in terms of reversible capacity, rate capability and cycling performance. It is established that such engineered anode can efficiently reduce the electrode pulverization and in turn make conversion reaction of tin partially reversible.