Carbon-Encapsulated Sn@N-Doped Carbon Nanotubes as Anode Materials for Application in SIBs

Abstract

Carbon-encapsulated Sn@N-doped carbon tubes with submicron diameters were obtained via the simple reduction of C@SnO@N-doped carbon composites that were fabricated by a hydrothermal approach. Sn nanoparticles encapsulated in carbon layers were distributed uniformly on the surfaces of the N-doped carbon nanotubes. The electrochemical performances of the composites were systematically investigated as anode materials in sodium-ion batteries (SIBs). The composite electrode could attain a good reversible capacity of 398.4 mAh g when discharging at 100 mA g, with capacity retention of 67.3% and very high Coulombic efficiency of 99.7% over 150 cycles. This good cycling performance, when compared to only 17.5 mAh g delivered by bare Sn particles prepared via the same method without the presence of N-doped carbon, could be mainly ascribed to the uniform distribution of the precursor SnO on the substrate of N-doped carbon tubes with three-dimensional structure, which provides more reaction sites to reduce the diffusion distance of Na, further facilitating Na-ion diffusion and relieves the huge volume expansion during charging/discharging. These outcomes imply that such a Sn/C composite would provide more options as an anode candidate for SIBs.

Graphene‐Encapsulated FeS2 in Carbon Fibers as High Reversible Anodes for Na+/K+ Batteries in a Wide Temperature Range

“…Although graphite is the most well‐known anode materials for LIBs and owns a theoretical capacity of 372 mAh g −1 , it shows very low capacity for SIBs (31 mAh g −1 ) and PIBs (279 mAh g −1 , corresponding to form KC 8 during potassiation), which is a major barrier to the practical application . Moreover, larger Na + /K + brings out serious volume expansion and electrode materials degeneration during the charge/discharge process, resulting in low capacity and cyclic instability . Therefore, it is of great importance to design nanostructure materials that will meet with high reversible capacity, high energy density, and fast Na + /K + storage.…”

Enhanced Interfacial Kinetics of Carbon Monolith Boosting Ultrafast Na‐Storage

“…And the high‐resolution transmission electron microscopy (HRTEM) images further demonstrate that the tin nanoparticles with ultrasmall size (<5 nm) uniformly decorated in carbonaceous structural scaffold (Figure e). Furthermore, from the corresponding selected‐area electron diffraction (SAED) pattern of TCM in Figure f, diffraction rings marked by the white arrow can be clearly observed, which corresponds to the (200), (220), (301), and (321) crystalline planes of tin . The diffraction rings marked by the yellow arrow correspond to the porous carbon framework.…”

Plasma‐Enabled Ternary SnO2@Sn/Nitrogen‐Doped Graphene Aerogel Anode for Sodium‐Ion Batteries

“…In the first cathodic scan, the SnO 2 /NGA shows a strong peak around 0.6–1.0 V, representing the irreversible formation of the solid electrolyte interface (SEI) and Na 2 O [Eq. (1)] . However, for the SnO 2 @Sn/NGA, only a weak and broad hump around 1.2 V can be observed and disappears in the subsequent scans, which is also due to the formation of SEI but less content of SnO 2 in the electrode.…”

“…(2)]. [39] In the following anodic scan, the SnO 2 @Sn/NGA shows dealloying peaks around 0.65 and 0.75 V, and a partially reversible oxidization peak of Sn to SnO 2 at 1.25 V. [41] The differences between the peak potential and the potential at the half peak j E P -E P/2 j are approximately 0.56 mV for both dealloying peaks, which are indications of good reversibility. In sharp contrast, only a large oxidization peak at 1.25 V can be observed for the SnO 2 /NGA, indicating a slow desodiation process.…”

“…In the first cathodic scan, the SnO 2 /NGA shows a strong peak around 1)]. [39,40] However, for the SnO 2 @Sn/NGA, only a weak and broad hump around 1.2 V can be observed and disappears in the subsequent scans, which is also due to the formation of SEI but less content of SnO 2 in the electrode. The peak located at 0.01-0.6 V for both electrodes can be ascribed to the alloying reaction Sn!Na x Sn [Eq.…”