SnO2 Anchored in S and N Co-Doped Carbon as the Anode for Long-Life Lithium-Ion Batteries.

Abstract

Tin dioxide (SnO2) has been the focus of attention in recent years owing to its high theoretical capacity (1494 mAh g−1). However, the application of SnO2 has been greatly restricted because of the huge volume change during charge/discharge process and poor electrical conductivity. In this paper, a composite material composed of SnO2 and S, N co-doped carbon (SnO2@SNC) was prepared by a simple solid-state reaction. The as-prepared SnO2@SNC composite structures show enhanced lithium storage capacity as compared to pristine SnO2. Even after cycling for 1000 times, the as-synthesized SnO2@SNC can still deliver a discharge capacity of 600 mAh g−1 (current density: 2 A g−1). The improved electrochemical performance could be attributed to the enhanced electric conductivity of the electrode. The introduction of carbon could effectively improve the reversibility of the reaction, which will suppress the capacity fading resulting from the conversion process.