One-Step Urothermal Synthesis of Li⁺-Intercalated SnS₂ Anodes with High Initial Coulombic Efficiency for Li-Ion Batteries

Abstract

Tin sulfide, as a promising anode material for Li-ion batteries, suffers from high-capacity loss during cycling and low initial Coulombic efficiency, which limits its further application. In order to solve these problems, Li + -intercalated SnS 2 with expanded interlayer spacing (0.89 nm) was prepared by the one-step urothermal method. The successful synthesis of Li + -intercalated SnS 2 is confirmed by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma emission spectrometer test, and exfoliation experiment. Compared with pure SnS 2 , the Li + -intercalated SnS 2 electrode displays a higher initial Coulombic efficiency (79.3%) than the pure SnS 2 electrode (55%). Also, Li + -intercalated SnS 2 exhibits more excellent rate performance (548.4 mAh g −1 at 2 A g −1 and 216.6 mAh g −1 at 10 A g −1 ) and cycling performance (647.7 mAh g −1 at 0.1 A g −1 after 100 cycles).

Covalent Bond Hybrid Nanostructure of N-doped rGO and Ultrathin SnS2 with High Porosity for Lithium-Ion Batteries

“…The reduction peaks located at ∼1.6 and ∼1.8 V attributed to the Li + embedding of SnS 2 without phase transition, and disappear in subsequent scans. In addition, the reduction peak at ∼1.25 V corresponds to the formation of the SEI layer and the decomposition of SnS 2 into Sn and Li 2 S (SnS 2 + 4Li + + 4e – → Sn + 2Li 2 S), which is the main cause of the initial irreversible capacity loss . The cathode peak of 0.1 V and the anode peak of 0.55 V are caused by the alloying and dealloying of Li x Sn (Sn + x Li + + x e – ↔ Li x Sn), and the oxidation peak at ∼1.9 V is related to the reversible reaction of Li 2 S .…”

“…In addition, the reduction peak at ∼1.25 V corresponds to the formation of the SEI layer and the decomposition of SnS 2 into Sn and Li 2 S (SnS 2 + 4Li + + 4e − → Sn + 2Li 2 S), which is the main cause of the initial irreversible capacity loss. 52 The cathode peak of 0.1 V and the anode peak of 0.55 V are caused by the alloying and dealloying of Li x Sn (Sn + xLi + + xe − ↔ Li x Sn), and the oxidation peak at ∼1.9 V is related to the reversible reaction of Li 2 S. 53 The slight shift of redox peaks located within ∼1.25 V from the first cycle to subsequent cycles can be attributed to the formation of irreversible SEI layers (possible Li 2 O species). 54 There is a good overlap between the oxidation and reduction peaks, indicating that the electrode has good reversibility.…”