Heterostructured Nanocube‐Shaped Binary Sulfide (SnCo)S₂ Interlaced with S‐Doped Graphene as a High‐Performance Anode for Advanced Na⁺ Batteries

Abstract

Heterostructuring electrodes with multiple electroactive and inactive supporting components to simultaneously satisfy electrochemical and structural requirements has recently been identified as a viable pathway to achieve high-capacity and durable sodium-ion batteries (SIBs). Here, a new design of heterostructured SIB anode is reported consisting of double metal-sulfide (SnCo)S 2 nanocubes interlaced with 2D sulfur-doped graphene (SG) nanosheets. The heterostructured (SnCo)S 2 /SG nanocubes exhibit an excellent rate capability (469 mAh g −1 at 10.0 A g −1 ) and durability (5000 cycles, 487 mAh g −1 at 5.0 A g −1 , 92.6% capacity retention). In situ X-ray diffraction reveals that the (SnCo)S 2 /SG anode undergoes a six-stage Na + storage mechanism of combined intercalation, conversion, and alloying reactions. The first-principle density functional theory calculations suggest high concentration of p-n heterojunctions at SnS 2 /CoS 2 interfaces responsible for the high rate performance, while in situ transmission electron microscopy unveils that the interlacing and elastic SG nanosheets play a key role in extending the cycle life.

Interlayer Expanded SnS2 Anchored on Nitrogen‐Doped Graphene Nanosheets with Enhanced Potassium Storage

“…By building equivalent circuit model (insert in Figure e) and calculating the parameters, the R ct value of SnS 2 @NC (1334 Ω) is much smaller than the pure SnS 2 (2884 Ω), which is accorded with our expectation, confirming that the delicate nitrogen‐doped graphene matrix can effectively enhance the electrical conductivity and decrease the charge transfer resistance of SnS 2 . Besides, another significant parameter of K + ion diffusion coefficient (D K + ) is also calculated according to the Equations S1 and Equation S2 ,. Based on the relationship between Z’ and ω −1/2 (Figure f), the slope of the oblique line ( σ ) is inversely proportional to the D K + .…”

“…Besides, another significant parameter of K + ion diffusion coefficient (D K + ) is also calculated according to the Equations S1 and Equation S2. [47,48] Based on the relationship between Z' and ω À 1/2 (Figure 6f), the slope of the oblique line (σ) is inversely proportional to the D K + . The SnS 2 @NC anode has a smaller σ with a larger D K + value (2.19 × 10 À 15 ), which is 1.5 times larger than SnS 2 (4.56 × 10 À 16 ).…”

Reduced Graphene Oxide Boosted Ultrafine Cu2SnS3 Nanoparticles for High‐performance Sodium Storage

“…Figure 2a compares the XRD patterns of CTS/RGO composite and bare CTS particle. [27,28] All of these issues are beneficial to the 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 sodium storage of CTS. The construction of heterogeneous composite could enhance the kinetics of redox reactions and charge transfer by the internal electric field at heterointerfaces.…”

“…[25,26] Besides, the existence of heterointerfaces could provide abundant electrode/electrolyte contact areas, as well as fast pathways for sodium ion diffusion along the mixed CTS boundaries. [27,28] All of these issues are beneficial to the 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 sodium storage of CTS. The relatively weak diffraction peaks of CTS/RGO composite demonstrate their characteristic of lower crystallinity, which is favorable to promote the (de)sodiation kinetics.…”

Heterointerface Engineering of Hierarchical Bi2S3/MoS2 with Self‐Generated Rich Phase Boundaries for Superior Sodium Storage Performance

“…Specifically, the generated intermediate Na 2 S will get agglomeration with uneven distribution, reducing the M 0 /Na 2 S interface and remaining the electrochemical‐inertness Na 2 S, which significantly impede the reverse conversion reaction with inferior reversibility of MS x . [ 16–18 ] Additionally, the electrons/Na + ‐ions transportation are restricted simultaneously, resulting in the sluggish reaction kinetics and unexpected capacity fading. [ 19 ]…”