Synergistical Coupling Interconnected ZnS/SnS₂ Nanoboxes with Polypyrrole‐Derived N/S Dual‐Doped Carbon for Boosting High‐Performance Sodium Storage

Abstract

Metal sulfides possess tremendous potentials owing to their high specific capacity for sodium storage. However, the huge volume expansion, accompanied with structural collapse and unsatisfied electric conductivity upon continuous cycling, always lead to inferior rate capability and severe cycling fading. In this work, binary metal sulfide (ZnS/SnS2) nanoboxes confined in N/S dual‐doped carbon shell (ZSS@NSC) are fabricated through a facile co‐precipitation method involving the wrapping of polypyrrole, and subsequent in situ sulfidation process. Such a well‐designed heterogeneity between ZnS and SnS2 provides rapid Na+ insertion and enhanced charge transport by creating an electric field at the heterointerface. More significantly, the formation of polypyrrole‐derived N/S dual‐doped carbon is synergistically coupled with the ZnS/SnS2 to create a unique and robust architecture, further strengthening the interconnect function at the heterointerface, which improves electric/ion transfer and mitigates the volume variation during the long‐term cycling process. Herein, this as‐prepared ZSS@NSC exhibits satisfied specific capacity, excellent rate property, and superior cyclic stability (a reversible capacity of 456.2 mAh g−1 with excellent capacity retention of 97.2% after 700 stable cycles at ultrahigh rate of 5 A g−1). The boosted Na‐storage properties demonstrate that the optimized strategy of structure‐engineering has a broad prospect to promote energy storage applications.

Recent Advances on Mixed Metal Sulfides for Advanced Sodium‐Ion Batteries

“…The pyrolysis of polymers is a simple and efficient approach for preparing carbonaceous materials, which has been widely used to in situ decorate the MMSs. Various polymers, such as poly(styrene-acrylic), [70] polydopamine (PDA), [71][72][73][74][75] poly(3,4-ethylenedioxythiophene), [76] polyacrylonitrile, [77] dextrin, [78] and polypyrrole [79,80] have been used as precursors to generate highly conductive carbon materials. For example, a carbon-coated Fe 9 S 10 @MoS 2 heterostructure was developed by Liu and co-workers.…”

Structural Engineering of SnS2Encapsulated in Carbon Nanoboxes for High‐Performance Sodium/Potassium‐Ion Batteries Anodes

“…[54,55] This is positive because strong coupling effect will occur at the heterointerface due to the heteroatoms doping induced electron cloud bias, thereby effectively accelerating the electron transport and offering more active sites for Na + /K + storage. [56] In view of the successfully doped N into the carbon shell, the material is expected to exhibit an enhanced ionic diffusion rate, which will benefit the rate capability.…”

Boosting Sodium Storage of Fe1−xS/MoS2 Composite via Heterointerface Engineering

“…The key point to achieve high-performance SIBs relies on the rational design of electrode materials with satisfactory Na ions insertion/extraction performance during repeated cycles, especially for the active anode host materials. Among the various anode materials, transition metal sulfides (M x S y ) have drawn extensive attentions due to their high sodium storage capacity [7][8][9][10]. Moreover, the weaker M-S bond than M-O bond is more kinetically favorable for electrochemical conversion reaction, leading to a better redox kinetics and reversibility [11].…”