Synthesis and characterization of high-performance and stability SnO2/C composite anode for Li-ion batteries

In the recent years, the massive spreading of electric devices led the research to focus on high energy density technologies, especially Li-ion batteries [1]. Furthermore, with the increasing development of hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs) and electric vehicles (EVs), high-energy and high-power materials must be found [2]. In this regard, a composite anode material based on SnO2 and amorphous carbon has been prepared by ultrasonic wave dispersion of commercial nanosize SnO2 powder in a sucrose solution, followed by thermal annealing in Ar, yielding an approximate SnO2:C ratio of 1:1. Structural characterization was pursued by XRD, SEM and TGA. Electrodes have been prepared using high-molecular weight PAA as binder. Cyclic voltammetry at different scan rates revealed a linear relationship between the peak current and the square root of scan rates, with an estimated lithium diffusion coefficient in accordance with literature [3,4]. Prolonged galvanostatic cycling showed improved stability and average specific capacity of 793 mAh g at a current of 500 mA g . Remarkable cycling stability has also been revealed by rate capability tests and confirmed by impedance analysis of interfacial phenomena. This relevant performance is apparently rooted in: (i) the role of carbon both in efficiently dispersing SnO2 and in enhancing electrode conductivity; (ii) the stabilization of SEI by the use of electrolyte additives.