The Dual Capacity Contribution Mechanism of SnSb‐Anchored Nitrogen‐Doped 3D Reduced Graphene Oxide Enhances the Performance of Sodium‐Ion Batteries

Abstract

Nanoscale SnSb alloys exhibit lower expansion rates and outstanding electrochemical properties, owing to the synergy between Sn and Sb for anode materials of sodium-ion batteries. However, nanomaterials with a high surface energy tend to aggregate and form larger secondary particles, limiting their further application. Herein, SnSb nanoparticles are prepared and distributed in three-dimensional networks of N-doped reduced graphene oxide (3D-rNGO), which plays a crucial role in inhibiting the agglomeration of SnSb nanoparticles, thereby promoting the capacitive contribution of surface drive. More importantly, the three-dimensional structure has a high specific surface area and the active region introduced by N doping can contact and adsorb more sodium ions as part of the electrochemical behavior, making the SnSb/3D-rNGO anode not only contribute capacity through a diffusion process, but also provide a capacitive contribution through a surface-driven mechanism. The results of the electrochemical analysis showed that SnSb/3D-rNGO, as the anode of a sodium-ion battery, exhibits a high specific capacity of 1169.6 mAh g À 1 , a reversible capacity of 55 % at 0.1 C, and maintains a capacity of 479.3 mAh g À 1 after 200 cycles. It is suitable for energy storage precisely because of the double capacity contribution mechanism.

Mesoporous ZnS-Sb/C Reduced Graphene Oxide Nanostructures as Anode Materials for Sodium-Ion Batteries

“…In Figure h, the peaks at 163.9 and 165.1 eV belong to S 2p 3/2 and S 2p 1/2 , indicating the presence of S 2– in the sample . In Figure i, the two peaks at 285.5 and 284.8 eV belong to C–O and C–C/CC bonds, respectively, confirming the presence of graphene and amorphous carbon layers in the composite. , …”

“…39 In Figure 3i, the two peaks at 285.5 and 284.8 eV belong to C−O and C−C/C�C bonds, respectively, confirming the presence of graphene and amorphous carbon layers in the composite. 40,41 The working mechanism of the ZnS-Sb@C@rGO sample was analyzed by cyclic voltammetry. Figure 4a gives the CV curves of ZnS-Sb@C@rGO at a voltage window of 0−3 V. It can be seen that during the first cycle of discharge, the first broad peak of ZnS-Sb@C@rGO will appear at around 2.0 V, which belongs to the process of forming a solid electrolyte interfacial (SEI) film.…”

Hexagonal Sb Nanocrystals as High-Capacity and Long-Cycle Anode Materials for Sodium-Ion Batteries

“…We repeated the regeneration of the solid electrolyte interface (SEI) layer, which inevitably resulted in its severe capacity decrease and unsatisfactory cyclability. 29−33 In consequence, various strategies have been carried out to combine Sb with other metals and carbon compounds to strengthen its cycle stability, such as Sb/Cu 2 Sb, 34 BiSb@Bi 2 O 3 /SbO x @C, 35 Sb 2 S 3 /CNTs, 36 CoSb, 37 NiSb, 38 ZnSb, 39 and SnSb, 40 which push greatly the progress in the cycle life and charging/discharging capacity of Sb-based SIB anodes. Despite this, to date, few reports about the hexagonal Sb nanocrystal are especially encapsulated by P/ N co-doped carbon nanofibers by electrospinning.…”

“…Accordingly, metal antimony (Sb) is deemed a potential anode material for the high-energy density SIBs owing to its high theoretical specific capacity (∼660 mAh g –1 ) and medium operating voltage (0.5–0.8 V vs Na + /Na). − However, the excessive volume expansion in the process of charging (Sb → Na 3 Sb: 390%) and discharging usually leads to the crushing and collapse of the fabricated electrodes as well as the weakening of the electrical contact. We repeated the regeneration of the solid electrolyte interface (SEI) layer, which inevitably resulted in its severe capacity decrease and unsatisfactory cyclability. − In consequence, various strategies have been carried out to combine Sb with other metals and carbon compounds to strengthen its cycle stability, such as Sb/Cu 2 Sb, BiSb@Bi 2 O 3 /SbO x @C, Sb 2 S 3 /CNTs, CoSb, NiSb, ZnSb, and SnSb, which push greatly the progress in the cycle life and charging/discharging capacity of Sb-based SIB anodes. Despite this, to date, few reports about the hexagonal Sb nanocrystal are especially encapsulated by P/N co-doped carbon nanofibers by electrospinning.…”

Blocky Sb/C Anodes with Enhanced Diffusion Kinetics for High‐Rate and Ultra‐Long Cyclability Sodium Dual‐Ion Batteries

“…However, when the sodium is stored in Sb host to form Na 3 Sb, approximately 393 % volume expansion will result in rapid capacity decay, [34] severely hindering the practical application. Hence, the effective combination of Sb and carbon matrix is the most promising method to have anode with superior electrochemical performance for SDIBs, including high working voltage and long cycle life at high current densities [35,36] …”