Solvent-Free Encapsulation of Ultrafine SnO₂ Nanoparticles in N-Doped Carbon for High-Capacity and Durable Lithium Storage

Abstract

SnO 2 has drawn great attention in lithium storage owing to the high theoretical capacity and appropriate lithiation potential. However, the low intrinsic conductivity and substantial volume variation severely hinder its further application in lithium-ion batteries (LIBs). Herein, we report a solvent-free carbon-coating strategy to encapsulate ultrafine SnO 2 nanoparticles into Ndoped carbon. The effective coupling of SnO 2 nanoparticles with high activity and N-doped carbon with high conductivity and mechanical stability provides the obtained SnO 2 @NC with a high reversible capacity of over 880 mAh g −1 with satisfactory durability. In situ transmission electron microscopy (TEM) characterization reveals that even with encapsulation in mechanically stable Ndoped carbon, pulverization of SnO 2 nanoparticles is unavoidable. However, the obtained SnO 2 @NC demonstrates excellent structural stability upon cycling. The scalable solvent-free synthesis, high capacity, and ideal durability make SnO 2 @NC a competitive LIB anode material.

Interconnected Sn@SnO2 Nanoparticles as an Anode Material for Lithium-Ion Batteries

“…In contrast, the charge scan displayed a reversible peak at 0.51 V vs Li/Li + , followed by a descendent slope between 0.67 and 1.21 V vs Li/Li + , and a broad and slight peak centered at 1.42 V vs Li/Li + . These peaks are ascribed to the delithiation reactions: (i) at low voltage, SnLi 4.4 → Sn + 4.4Li and (ii) at high voltage, Sn + 2Li 2 O → SnO 2 + 4Li . The subsequent CV curves overlap consistently.…”

“…The cyclic voltammograms (CVs, Figure a) show that during the 1st discharge scan, irreversible broad bands appeared around 1.11, 0.53, and 0.23 V vs Li/Li + . These bands are attributed to the formation of a solid-electrolyte interphase (SEI) layer and the lithium-ion storage in the Sn@SnO 2 -based electrode . In contrast, the charge scan displayed a reversible peak at 0.51 V vs Li/Li + , followed by a descendent slope between 0.67 and 1.21 V vs Li/Li + , and a broad and slight peak centered at 1.42 V vs Li/Li + .…”

Carbon confined GeO2 hollow spheres for stable rechargeable Na ion batteries

“… 57 Generally, the doping of N elements improves the electrochemical reactivity and electron conduction of the material, which in turn leads to higher charge/discharge capacity. 58 The capacity loss in the first cycle (425 mA h g −1 ) may be caused by the formation of an irreversible SEI layer in the initial cycle.…”

Rational Design and Engineering of 1D Heterostructured Porous Sn/CoSnx@C Nanotubes for Superior Lithium Storage

“…Cyclic voltammetry (CV) curves were tested at a scanning rate of 0.01 mV s −1 between 0.01 and 3 V (Figure 4a). In the first discharge cycle, the two irreversible peaks appearing at 1.4 and 0.78 V can correspond to the reaction between CoSn x and lithium and the formation of the solid electrolyte interface (SEI) film, 23,54,55 and the cathode peak at 0.1 V can be attributed to the formation process of Li x Sn alloying. 56 In contrast, in the first charging cycle, the anodic peaks at 0.49, 1.25, and 2.06 V correspond to the dealloying reaction of Li x Sn, 57 the oxidation reaction of Sn, 55,58 and the electrochemical reaction of carbon shell, respectively.…”

“…In the first discharge cycle, the two irreversible peaks appearing at 1.4 and 0.78 V can correspond to the reaction between CoSn x and lithium and the formation of the solid electrolyte interface (SEI) film, 23,54,55 and the cathode peak at 0.1 V can be attributed to the formation process of Li x Sn alloying. 56 In contrast, in the first charging cycle, the anodic peaks at 0.49, 1.25, and 2.06 V correspond to the dealloying reaction of Li x Sn, 57 the oxidation reaction of Sn, 55,58 and the electrochemical reaction of carbon shell, respectively. 14,50 After the second cycle, the curves overlap almost completely, indicating outstanding cyclic stability of the Sn/CoSn x @C anode, while the CV curves of the contrast anodes show obvious differences (Figure S13).…”