C‐Plasma of Hierarchical Graphene Survives SnS Bundles for Ultrastable and High Volumetric Na‐Ion Storage

Abstract

limited space becomes a critical parameter. The conventional carbo naceous anodes are limited by their relatively low sodium storage capacity. [1,2] Recently, alloying-type anodes, such as Sb nanorod, [3] SnS nanohoneycomb, [4] SnO nanosheet, [5] and branched SnS 2 , [6] have been extensively reported to possess enhanced sodium-ion gravimetric, areal, and volumetric storage capacities. But the cycling stability is still a major bottleneck.Great efforts have been dedicated to improving the cycling stability of the battery electrodes, particularly alloy-type materials. A well-defined conductive network is essential to accommodate the large volume change, stabilize the structure, and supply conductive channels. [7][8][9] Current research has shown that the combination of graphene, or more commonly, reduced graphene oxide (rGO), with metal oxides, sulfides, and metal alloys can significantly enhance the sodium storage performance. [8,[10][11][12][13][14] For instance, Yu et al. reported that Sb 2 S 3 /graphene composite gave a high capacity of 730 mAh g −1 and a stable charge/ discharge performance in 50 cycles. [15] SnS 2 /graphene [16] and SnS/graphene [17] nanosheets prepared by hydrothermal method with graphene oxide showed a high reversible capacity of 940 mAh g −1 at 0.03 A g −1 with 250 cycles at 7.29 A g −1 and 630 mAh g −1 at 0.2 A g −1 with 400 cycles at 1.0 A g −1 , respectively. In another work, SnO 2 /SnS/graphene heterostructure [18] delivered 729 mAh g −1 at 0.03 A g −1 with enhanced cycling stability of 500 cycles at 2.43 A g −1 . However, these laminate structures inevitably introduce excess exposure of active materials to the electrolyte, which will form thick solid-state electrolyte interface (SEI), aggregate and detach gradually from the graphene surface. Regrettably, this counters the attempt to obtain long-term cycling life with maintained high capacity.It remains a big challenge to in situ grow robust graphene onto everywhere of active material nanoarchitectures, especially for the alloying-type electrode materials.In this work, we develop a facile and rapid C-plasma strategy to in situ generate robust hierarchical graphene (hG) bundled onto tin sulfide networks to stabilize its long-cycle capacity for reversible Na-ion storage. This also illustrates that tin is applied as catalyst for the growth of graphene (growth mechanism is supported by density functional theory calculations). In contrast to the conventional laminate graphene composite structure, chemical-bonded hG provides continuous and permanently Tin and its derivatives have provoked tremendous progress of high-capacity sodium-ion anode materials. However, achieving high areal and volumetric capability with maintained long-term stability in a single electrode remains challenging. Here, an elegant and versatile strategy is developed to significantly extend the lifespan and rate capability of tin sulfide nanobelt electrodes while maintaining high areal and volumetric capacities. In this strategy, in situ bundles of robust hierarchical gr...

Space‐Confined Atomic Clusters Catalyze Superassembly of Silicon Nanodots within Carbon Frameworks for Use in Lithium‐Ion Batteries

“…The high‐resolution TEM image in Figure d reveals that the carbon component in the composite is partially graphitized; that is, it is divided into two microdomains of layered g‐carbon nanosheets and a‐carbon, while Si NDs are uniformly distributed in the interspaces of g‐carbon nanosheets. The formation of g‐carbon nanosheets on the surface or surrounding Si NDs in the interior of the composite microspheres are a consequence of the catalytic effect of the Sn catalyst; this is made clear by comparisons with the product obtained under the same conditions, or in the absence of Sn (Figure S5). The elemental mappings of a composite microsphere (Figure e) show that C, Si, and Sn are homogeneously distributed throughout.…”

1T′‐ReS2 Confined in 2D‐Honeycombed Carbon Nanosheets as New Anode Materials for High‐Performance Sodium‐Ion Batteries

“…This implies a significant contribution of the pseudocapacitive process. [50][51][52] Moreover, the capacitive contribution at different scan rates can be quantitative analyzed: i(V) = k 1 v + k 2 v 0.5 (constants k 1 and k 2 are associated with, respectively, pseudocapacitive and diffusioncontrolled process). [50][51][52] Moreover, the capacitive contribution at different scan rates can be quantitative analyzed: i(V) = k 1 v + k 2 v 0.5 (constants k 1 and k 2 are associated with, respectively, pseudocapacitive and diffusioncontrolled process).…”

“…[51] High capacitive contribution results in high rate performance. [50][51][52][53] A typical CV curve of the capacitive contribution is quantified in Figure S10b (Supporting Information). [50][51][52][53] A typical CV curve of the capacitive contribution is quantified in Figure S10b (Supporting Information).…”

Chem‐Bonding and Phys‐Trapping Se Electrode for Long‐Life Rechargeable Batteries

“…The electrochemical properties of materials could be affected by many factors, including material structure, effective quality, current density, assembling battery technology, etc. In addition, the cycling performance of the carbon skeleton is also tested, showing the capacitive capacity of only about 60 mA h g −1 at a current density of 100 mA g −1 (Figure b) . Thus the capacity of the Se‐CPSe electrode is mainly coming from the chem‐bonding Se and phys‐trapping Se.…”