Controlled SnO₂ Crystallinity Effectively Dominating Sodium Storage Performance

Abstract

The exploration of sodium ion batteries (SIBs) is a profound challenge due to the rich sodium abundance and limited supply of lithium on earth. Here, amorphous SnO2/graphene aerogel (a‐SnO2/GA) nanocomposites have been successfully synthesized via a hydrothermal method for use as anode materials in SIBs. The designed annealing process produces crystalline SnO2/graphene aerogel (c‐SnO2/GA) nanocomposites. For the first time, the significant effects of SnO2 crystallinity on sodium storage performance are studied in detail. Notably, a‐SnO2/GA is more effective than c‐SnO2/GA in overcoming electrode degradation from large volume changes associated with charge–discharge processes. Surprisingly, the amorphous SnO2 delivers a high specific capacity of 380.2 mAh g−1 after 100 cycles at a current density of 50 mA g−1, which is almost three times as much as for crystalline SnO2 (138.6 mAh g−1). The impressive electrochemical performance of amorphous SnO2 can be attributed to the intrinsic isotropic nature, the enhanced Na+ diffusion coefficient, and the strong interaction between amorphous SnO2 and GA. In addition, amorphous SnO2 particles with the smaller size better function to relieve the volume expansion/shrinkage. This study provides a significant research direction aiming to increase the electrochemical performance of the anode materials used in SIBs.

Recent Progress in Iron‐Based Electrode Materials for Grid‐Scale Sodium‐Ion Batteries

“…Anode materials also play an important role in the development of SIBs. Many anode materials, such as carbonaceous materials, alloys, oxides, and sulfides, have shown good sodium storage performance. For the iron‐based materials, Fe 2 O 3 and Fe 3 O 4 with multiple electron reactions are investigated.…”

A Water‐Soluble NaCMC/NaPAA Binder for Exceptional Improvement of Sodium‐Ion Batteries with an SnO2‐Ordered Mesoporous Carbon Anode

“…[61] For the aqueousb inder electrodes, the 286.7 eV peak was associated with CÀOb onding (for NaCMC), and the 288.5 eV peak was ascribed to the ÀCOONa group (for both NaCMC and NaPAA). [32,64] Interestingly,t he normalized peak intensity for the electrodes decreased in the sequence PVDF > NaCMC > NaPAA > NaCMC/NaPAA. The 3d 5/2 and Sn 3d 3/2 peaks located at 487.5 and 496.1 eV,r espectively,c onfirmed that the valence of Sn was + 4.…”

“…However,t he experimental data confirmt hat our anode with an appropriate binder had am uch higher volumetric capacity than that (130 mAh cm À3 )o fahard carbon electrode, which is the most commonly studied NIB anode. The apparent Na + diffusion coefficients (D Na + )f or the electrodes were calculated from the oblique linear Warburg parts; [64] the calculated values for these electrodes were 1.7 10 À16 ,3 .8 10 À15 ,6 .1 10 À15 ,a nd 8.3 10 À15 cm 2 s À1 , respectively.T he tightly packed SnO 2 @CMK-8 NPs can form af avorable Na + diffusion pathway,w hich resultedi na ne nhanced transport rate. As revealed in the Nyquist plots in Figure 5c,t he spectra consisted of as emicircle at high frequency and a sloping line at low frequency,w hich can be characterized by the equivalent circuit shown in the inset, in which R e , R ct , CPE,a nd W are the electrolyte resistance, interfacial charget ransfer resistance, interfacial constant phase element, and Warburg impedance associated with Na + diffusion in the electrode, respectively.…”

Submicron‐sized Sb 2 O 3 with hierarchical structure as high‐performance anodes for Na‐ion storage

“…During the first cathodic scan, a strong 0.4‐V reduction peak appeared followed by a smaller reduction peak at approximately 0.1 V. The strong reduction peak should be ascribed to a sodiation of Sb 2 O 3 to produce Na 2 O and Sb as well as partial sodiation of the generated Sb to from Na x Sb, while the latter one corresponds to the further sodiation of Na x Sb to form Na 3 Sb . The second cathodic scan changes a lot compared with the first one due to a structure modification and solid electrolyte interphase (SEI) formation in an initial sodiation process, which can be generally observed in the materials that undergo conversion‐alloying storage mechanism . Specifically, the second cathodic scan displays four reduction peaks at 0.80, 0.55, 0.35, and 0.15 V. The peak at 0.80 V comes into being from a Sb 2 O 3 sodiation to form Sb and Na 2 O, while the remaining three peaks originate from the progressively sodiation of Sb to form Na 3 Sb .…”