SnS−SnO₂Heterostructures Anchored on GO as a High‐Performance Anode for Sodium Ion Battery

Abstract

SnO 2 is a theoretically excellent transformed anode material with high theoretical capacity for SIBs. However, SnO 2 faces serious volume effect and high resistance, which greatly damages its electrochemical performance. Given that, the SnSÀ SnO 2 heterostructures is constructed with special internal electric field, which is beneficial to promote the transfer ability of sodium ions. Besides, the graphene oxide (GO) modification is carried out to isolate the intrinsic materials from direct contact with electrolyte, and alleviate volume expansion of the anode, ultimately promote the electrochemical performance. Furthermore, the structure and the conductivity characteristics of SnS, SnO 2 , SnSÀ SnO 2 and SnSÀ SnO 2 @ GO are simulated respectively by first principles and are compared with the correspondence experiment results to verify the accuracy of established models. Owing to the special p-n junction in SnSÀ SnO 2 @GO heterostructures, the resistance of SnSÀ SnO 2 @GO can be reduced to 36.23 Ω, much lower than that of SnO 2 (Rct = 341.9 Ω). Notably, the combination of GO has effectively alleviated the volume expansion of SnSÀ SnO 2 @GO electrodes, and present excellent capacity higher than 384.7 mAh g À 1 after 100 cycles. Thus, the efficient synthesis of SnSÀ SnO 2 @GO heterostructure electrodes with excellent performance for sodium storage is expected to provide valuable direction for SIBs anode materials.

Facile Fabrication of an SnSx‐SnO2‐Decorated Cobalt Sulfide Film as an Effective Counter Electrode for Dye‐Sensitized Solar Cells

“…[26][27][28] Here, the binding energies of S 2p 1/2 and S 2p 3/2 shift to larger values, indicating the formation of SnS x . [26][27][28] Additionally, Sn 3d spectrum and O 1s spectrum demonstrate the formation of SnO 2 film, as shown in Figure 2(c-d). [20] Therefore, the results from SEM and XPS demonstrate that SnS x -SnO 2 -decorated CoS x films have been successfully prepared by the low-temperature fabrication technique.…”

“…[26,27] Meanwhile, the peaks at 163.55 eV and 162.39 eV are attributed to S 2p 1/2 and S 2p 3/2 for SnS x -SnO 2decorated CoS x film, respectively. [26][27][28] Here, the binding energies of S 2p 1/2 and S 2p 3/2 shift to larger values, indicating the formation of SnS x . [26][27][28] Additionally, Sn 3d spectrum and O 1s spectrum demonstrate the formation of SnO 2 film, as shown in Figure 2(c-d).…”

SnO2/SnS heterojunction anchoring on CMK-3 mesoporous network improves the reversibility of conversion reaction for lithium/sodium ions storage

“…In the initial cathodic scanning curve, there are two reduction peaks at 0.83 V and 0.43 V. The reduction peak at 0.83 V represents the conversion processes of SnO 2 to Sn and Na 2 O, SnS to Sn and Na 2 S (equations (4), ( 5)) [28,55]. The reduction peak at 0.43 V represents the formation of Na x Sn alloy (equation ( 6)) and irreversible reaction processes such as the electrolyte interface film (SEI) [26,40]. In subsequent cathodic curves, the two reduction peaks shift toward higher potentials, which are located at 0.96 V and 0.64 V in the second cathodic curves, respectively.…”

“…However, due to the poor reversibility of chemical reaction thermodynamics and kinetics, this conversion reaction of SnO 2 is usually not reversible in battery reactions, for which the theoretical capacity of SnO 2 is reduced by about 50% [1,12]. In addition, SnO 2 is an oxygen-deficient n-type semiconductor with poor conductivity, which limits the kinetic characteristic of the battery reaction [14,15]. Researchers have improved the battery performance of SnO 2 by using the research strategy of nanomaterial and carbon composite, but the problems of intrinsic conductivity and reversible reactivity remain serious [5,16].…”

“…Therefore, the design strategy of heterojunction is expected to impove the electrochemical reaction performance of SnO 2 anode material. Among the Sn-based materials, SnS is another potential electrode material [25,26]. Compared with the N-type semiconductor structure (3.8 eV) of SnO 2 , SnS is a p-type semiconductor structure (1.3 eV) with narrower and smaller band gap energy and higher conductivity, which makes SnS show higher battery reactivity and reversibility [27,28].…”