C/Sn/RGO Nanocomposites as Higher Initial Coulombic Efficiency Anode for Sodium‐Ion Batteries

Abstract

Theoretically, metal Sn owns higher initial coulombic efficiency than SnO2 in the sodium‐ion batteries (SIBs). Metal Sn is commonly obtained by the thermal reduction of SnO2 at present. However, the uncontrollable growth of metal Sn particles during the reduction progress is a key challenge. In this work, a composite material of refined metal Sn particles (particle size about 20∼200 nm) and carbon buffer medium has been prepared by a novel method, which is simple thermal reduction adopted after the treatment of SnO2/RGO in the pitch kerosene solution. The results show that this method overcomes the uncontrollable growth of metal Sn particles. Electrochemical tests show that C/Sn/RGO possesses a higher initial reversible capacity of 476.2 mAh g−1, and a higher initial coulombic efficiency of 70.3%. This method would have wider applications for the attractive properties of Na‐ion batteries in the future.

Flexible Conductive Anodes Based on 3D Hierarchical Sn/NS-CNFs@rGO Network for Sodium-Ion Batteries

“…Three oxidation peaks in the anodic scans at 0.28, 0.58, and 0.73 V correspond to desodiation of Na 15 Sn 4 , NaSn, and NaSn 5 , respectively. The desodiation potentials observed in this work are well-agreemented with the experimental and calculated results for Sn-based anodes in the literature [ 24 , 47 – 49 ]. The overall reaction process of Sn/NS-CNFs@rGO composite in SIBs is given by Eqs.…”

“…It is noteworthy that the 3D flexible conductive Sn/NS-CNFs@rGO network fabricated in this work exhibited excellent high-rate capability and outstanding cycling stability as compared with various previously reported Sn-based anode materials (Fig. 4f) [20,22,24,28,45,49,50,[52][53][54][55][56] and other reported 3D free-standing electrodes (Table S1). For comparison, Sn/ NS-CNFs@rGO electrodes with lower/higher Sn content (denoted as L-Sn/NS-CNFs@rGO and H-Sn/NS-CNFs@ rGO) were also prepared by altering the mass ratio of metal salts and carbon source, where the Sn content of L-Sn/NS-CNFs@rGO and H-Sn/NS-CNFs@rGO is determined to be ~ 23.2 wt% and ~ 37.4 wt% from TG analysis (Fig.…”

Carbon‐Based Alloy‐Type Composite Anode Materials toward Sodium‐Ion Batteries

“…The carbon encapsulated bimetallic SnCo@C composite exhibited a good stability illustrating that the Sn–Co alloy core was superior to pure Sn in SIBs, as the Co acts as a stable and highly conductive network for augmenting reversibility of Sn while sodiation/desodiation and enabling the faster Na‐ion diffusion, and this type of intermetallic additives are beneficial for hindering the active materials aggregation . In this format, the composite of C/Sn/reduced graphene oxide (RGO) possesses a higher initial reversible capacity of 476.2 mAh g −1 with a CE of 70.3% reported by Dong et al Various methods have been proposed to make Sn nanoparticles with Sb element over graphene sheets to explore the efficient way to buffer the mechanical stress, improve the conductivity, and occur a high capacity of the composites since graphene is more flexible and bendable . In fact, these nanocomposites also display their versatility as a high‐capacity anode for SIBs .…”

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

“…Na 2 O formed by the conversion reaction can prevent agglomeration and accommodate the associated volume expansion. [13][14][15][16][17][18][19] However, the formation of Na 2 O consumes Na + ions in the electrolyte thus leading to the large irreversible capacity loss and low initial coulombic efficiency (CE) [Eqs. (1) and (2)].…”