N-Doped Carbon Coated SnS/rGO Composite with Superior Cyclic Stability as Anode for Lithium-Ion Batteries
Deliang Cheng, Min Lin, Jiangwen Liu, Lichun Yang, Yiwang Chen, Min Zhu
Abstract
Tin monosulfide (SnS), showing great prospect for lithium-ion batteries (LIBs), is restricted by its low conductivity and severe volume change during cycling. Moreover, severe agglomeration of SnS grains is ineluctable in the synthesis processes. Herein, the composite with both amorphous carbon and reduced graphene oxide (rGO) has been considered as an effective strategy to solve these problems. We have constructed a layered-structure of SnS particles anchored on rGO sheets with N-doped carbon coated on the grain surface. This dual-carbon structure successfully achieves uniform dispersion and restricted growth of grains, which is demonstrated by XRD, SEM, and TEM analyses. Besides, the introduction of N-doped carbon coating and rGO supporting effectively mitigates drastic volume change as well as enables excellent electronic conductivity of SnS during discharge/charge processes. Therefore, as anode for LIBs, the N-doped carbon coated SnS/rGO composite (SnS@N-C/rGO) shows outstanding rate capability and cycling performance. At 0.1 A g–1, it delivers a high initial reversible capacity of 1068.9 mAh g–1. Even at 1.0 A g–1, it also shows a high initial reversible capacity of 885.3 mAh g–1 and maintains 824 mAh g–1 after 550 cycles. Thus, the dual-carbon modification is a feasible strategy to promote the electrochemical properties of SnS and contribute alternative anodes for LIBs.