CoSe2 Nanocrystals Research Articles

CoSe2 nanocrystals embedded in one-dimensional mesoporous carbon nanofibers as advanced anode for potassium-ion storage

High-performance potassium-ion batteries have received great attention for electrochemical energy storage owing to their low redox potential, abundant natural resources and excellent safety. As an advanced negative material, CoSe2 has been widely investigated for potassium-ion batteries. Unfortunately, the pure CoSe2 anode suffers from the fast capacity decay and sluggish kinetics, preventing its practical application. Herein, we introduce a novel strategy to fabricate the CoSe2 nanoparticles embedded in one-dimensional mesoporous carbon nanofibers (denoted as 1D-CoSe2@CNFs) with superior high-rate property and good cycle stability for the first time. In this designed material, the conductive carbon nanofibers are loaded with CoSe2 particles. The obtained 1D-CoSe2@CNFs anode shows a specific capacity of 706.3 mAh/g at 0.1 A/g and presents a high capacity retention ratio of around 96.3 % at 5 A/g over 400 cycles. Therefore, this fabricated 1D-CoSe2@CNFs nanocomposite can be employed as a novel negative electrode for potassium-ion storage.

Constructing a mesoporous carbon nanobowls embedded with ultrafine CoSe2 Nanocrystals for High-Performance potassium ion battery electrode

In the quest for advanced electrode materials for potassium ion batteries (KIBs), an innovative anode featuring ultrafine CoSe2 nanocrystals embedded within mesoporous carbon nanobowls (CoSe2@MCNBs) is presented herein. Diverging from conventional hollow carbon nanospheres, the distinctive bowl structure is crafted to enhance the structural integrity and volumetric energy density of the electrodes. CoSe2@MCNBs synthesized using an iterative drop and dry method followed by selenization exhibit well-preserved morphology with a shell thickness of 20 nm. The successful integration of ultrafine CoSe2 nanocrystals into MCNBs imparts the nanobowls with the benefits of conventional hollow carbon-based composites, including abundant ion storage sites and high electrical conductivity. Simultaneously, the bowl structure boasts a higher packing density than the conventional hollow mesoporous carbon sphere (HMCS) structure, significantly augmenting the volumetric energy density of the fabricated electrode. Capitalizing on these advantages, the CoSe2@MCNB electrode displays exceptional cycling stability, achieving a reversible capacity of 523 mA h g−1 after 500 cycles at 0.5 A/g and an impressive rate capacity of 247 mA h g−1 at 2.0 A/g. This study demonstrates the strong potential of CoSe2@MCNB as an electrode material for the next generation of KIBs.

Octahedral CoS2 electrocatalysts for efficient nitrate reduction to ammonia

Octahedral CoS2 nanocrystals are highly active to ambiently reduce NO3− to NH3 (NO3RR). DFT calculations reveal that CoS2 (111) with high electron supply capacity is responsible for enhanced NO3RR activity.

Long-term stability of lithium–sulfur batteries via synergistic integration of nitrogen-doped graphitic carbon-coated cobalt selenide nanocrystals within porous three-dimensional graphene-carbon nanotube microspheres

Three-dimensional porous microspheres consist of highly conductive reduced graphene oxide-carbon nanotube (rGO‒CNT) framework with well-embedded cobalt selenide (CoSe2) nanocrystals coated with N-doped graphitic carbon (NGC) were synthesized (referred as “P–CoSe2@NGC/rGO‒CNT” microspheres) and utilized as an electrocatalytic interlayer to enhance the performance of lithium-sulfur (Li–S) batteries. The incorporation of the NGC layer and rGO‒CNT framework not only enhances the electronic conductivity significantly but also offers numerous conductive pathways (primary and secondary) for efficient electron transport. Macropores (φ = 100 nm) formed by the decomposition of PS nanobeads (φ = 200 nm) guarantee effective electrolyte penetration and short diffusion pathways. Moreover, the CoSe2 nanocrystals offer a multitude of polar active sites that effectively anchor polysulfide intermediates, reducing the loss of active material. Benefiting from the nanostructure merits, Li–S cells featuring a P–CoSe2@NGC/rGO‒CNT-coated separator and a conventional sulfur electrode demonstrated outstanding rate capability (up to 2.0 C) and remarkable cycling stability (1000 cycles at 2.0 C). Even under more demanding cell conditions, such as high sulfur content (71 %), high sulfur loading (4.6 mg cm−2), and low E/S (5.6 μL mg−1) ratio, the cell exhibits impressive cycling stability with 420 cycles at 0.1 C, along with feasible rate performance up to 0.3 C.

MoS2–CoS2 synergistic nanoarchitecture-based hollow microspheres for long-life thermal batteries

CoS2 is considered as a substitute cathode material for FeS2 in long-life thermal batteries due to its higher thermal stability. However, the CoS2 nanocrystals synthesized by hydrothermal method suffer from serious agglomeration and high crystal defects, which limit their specific capacity and thermal stability. Here, we successfully synthesized a MoS2–CoS2 synergistic nanoarchitecture-based hollow microsphere through a facile one-pot hydrothermal route. A three-stage growth mechanism of MoS2–CoS2 microsphere during the evolution process is revealed. The agglomeration problems are solved and the electrochemical properties are improved due to the porous loose structure as well as the synergistic effect of CoS2 and MoS2. As a result, MoS2–CoS2 cathode exhibits a long discharge time of 4800 s and a large specific capacity of 333.33 mAh g−1 at a current density of 50 mA cm−2 under a cut-off voltage of 1 V at 500 °C. Moreover, good pulse stability and thermal shock resistance are also achieved. This work provides a promising design strategy for cathode materials with high stability and high capacity to realize long-life thermal batteries.

Growth of Co9S8 Islands on Cu2S Nanodisks

Nanosized heterojunctions enable the study of physical processes such as charge transfer and also present a substrate to realize low-dimensionality devices. Here, we describe the formation of pristine heterojunctions between Cu2S and Co9S8. We observed heterojunction formation in a single reaction. Heteroassembly occurs due to the Cu2S nanodisk (ND)-assisted nucleation of Co9S8 nanocrystals (NCs). Evidence for this mechanism comes from the observation of epitaxy between the two materials. Heteroassemblies exhibit emergent physical properties that are absent in the two independent phases.

Hollow porous carbon nanospheres containing polar cobalt sulfide (Co9S8) nanocrystals as electrocatalytic interlayers for the reutilization of polysulfide in lithium–sulfur batteries

HypothesisThe introduction of functional interlayers for efficient anchoring of lithium polysulfides has received significant attention worldwide. ExperimentsA facile wet-chemical method was adopted to obtain hollow porous carbon nanospheres (HPCNSs) impregnated with metallic and polar cobalt sulfide (Co9S8) nanocrystals (abbreviated as “Co9S8@HPCNS”). The prepared nanocrystals were employed as electrocatalytic interlayers via separator coating for the efficient capture and reutilization of polysulfide species in Li-S batteries. The HPCNSs were synthesized via the polymerization method followed by carbonization and template removal. The Co9S8 nanocrystals were impregnated inside the HPCNSs, followed by heat treatment in a reducing atmosphere. FindingsThe porous structure of the CNS enables the efficient percolation of the electrolyte, in addition to accommodating unwanted volume fluctuations during redox processes. Furthermore, the metallic Co9S8 nanocrystals improve the electronic conductivity and enhance the polarity of the CNS towards the polysulfide. Correspondingly, the Li–S cells featuring Co9S8@HPCNS as electrocatalytic interlayers and regular sulfur (S) electrodes display improved electrochemical performance such as reasonable rate performance and prolonged cycling stability at different current rates (0.1, 0.5, and 1.0 C). Therefore, we anticipate that the rational design strategy proposed herein will provide significant insights into the synthesis of advanced materials for various energy storage applications.

Fabrication of Z-scheme Cd0.85Zn0.15S/Co9S8 dual-functional photocatalyst for effective hydrogen evolution and organic pollutant degradation

A Z-scheme Cd0.85Zn0.15S/Co9S8 (CZS-CS) photocatalyst was reasonably fabricated by a simple solvothermal method for the effective visible-light-driven H2 evolution and organic pollutants degradation. The precise construction of the CZS-CS composites provided an efficient heterogeneous contact interface and abundant reaction sites for the proposed photocatalytic reaction. The homogeneous Co9S8 nanocrystals were uniformly wrapped on the surface of Cd0.85Zn0.15S nanorods, forming an intimate-contact interface, markedly contributed to the light collection and effectively inhibited the charge-carrier recombination. The optimized CZS-CS-15 composites exhibited a special H2 production rate reaching 19.15 mmol·h−1·g−1, roughly 1915 and 4.5 times of pure Co9S8 and Cd0.85Zn0.15S samples and 85% of tetracycline (TC) molecule within 15 min was degraded. Furthermore, trapping experiments confirmed that h+ was the main active species for TC photodegradation. Moreover, the obtained photocatalysts manifested stability without apparent activity declines during the proposed reactions. Finally, the Z-scheme photocatalytic mechanism was verified to illustrate the characteristics of efficient charge transfer and high redox ability. This study provided a rational and learnable strategy for designing dual-functional Z-scheme heterojunction photocatalysts.

CoSe2 nanocrystals embedded into carbon framework as efficient bifunctional catalyst for alkaline seawater splitting

Herein, CoSe 2 nanocrystals embedded into carbon framework grown on carbon cloth is developed to catalyze the overall seawater splitting. • CoSe 2 nanocrystals embedded into carbon framework is synthesized as bifunctional catalyst for overall seawater splitting. • The catalyst shows overpotentials of 245 and 134 mV for OER and HER to reach 10 mA cm –2 , respectively. • The catalyst can operate at 1.842 V with a current density of 500 mA cm -2 in a two-electrode electrolyzer and work for 50 h. Direct seawater splitting is more attractive and feasible in realizing hydrogen economy, but the key challenge lies in the development of efficient and stable bifunctional electrocatalysts toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, CoSe 2 nanocrystals embedded into carbon framework grown on carbon cloth are successfully designed, featuring cooperative effect of CoSe 2 and nitrogen-doped carbon framework, which endow the excellent performance toward overall seawater splitting. The catalyst requires overpotentials of 245 and 134 mV for OER and HER to reach 10 mA cm –2 , respectively. Meantime, this catalyst also maintains robust electrocatalytic activity during over 50 h. Further, in the two-electrode alkaline seawater splitting electrolyzer, the catalyst shows a working voltage of 1.842 V to deliver 500 mA cm –2 at 80 o C, suggesting promising applications in sustainable hydrogen production. Our work may shed light on developing advanced and cost-effective electrocatalysts toward seawater splitting.

Simple fabrication of homogeneous Co/Co9S8/nitrogen doped carbon nanospheres derived from Prussian blue analogues for high performance supercapacitors

In this paper, an N-doped porous carbon (N-C) nanosphere containing a large amount of Co and Co9S8 nanocrystals (Co/Co9S8/N-C) is described. Among them, ZnCo-PBA (Zn3[Co(CN)6]2) was synthesized by simple method as the sacrificial template and carbon source. After calcination in N2, Co ions are reduced to Co, and zinc ions are vaporized to produce a large number of pores. Finally, it was vulcanized by hydrothermal method to form Co9S8 nanocrystals with high activity. Co/Co9S8/N-C nanomaterials have excellent specific surface area and mesoporous pores, which increase the charge transfer rate in the redox process and the performance. The material not only has excellent specific capacity (141.83 mAh g−1/1542.64 F g−1 at 1 A g−1), but also retains good specific capacity after thousands of charges and discharges. To further test the value of Co/Co9S8/N-C electrodes, an asymmetric supercapacitor (ASC) was assembled with a very high energy density (94.632 Wh kg−1) at 29368.55 W kg−1. The specific capacitance is about 80.70 % of the initial value after 5000 cycles. This strategy of using PBA as template to construct N-doped carbon skeleton embedded with metal sulfide provides a broad idea for supercapacitor electrode materials.

Ultrasmall Co9S8 nanocrystals on Carbon Nanoplates for Efficient Bifunctional Oxygen Electrocatalysis

Electrochemical energy storage and conversion technologies based on electrocatalysis have been attracting more and more attention addressing increasing concerns on fossil fuel crisis and environmental deterioration. Fuel cells, zinc-air batteries, and water electrolyzer are believed to be promising candidates due to the environmental friendliness and high efficiency. These systems are associated with key reactions including oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Due to slow kinetics of these reactions, efficient electrocatalysts, e.g., Pt for ORR and RuOx/IrOx for OER, are usually required to overcome the energy barrier in electrochemical reactions to increase the reaction rate. However, the most advanced electrocatalysts are still based on above-mentioned noble metals with high cost and scarcity, which inevitably retards the large-scale commercialization of these noble metal-based energy systems. It is of great significance to replace noble metal catalysts with earth-abundant, cost-effective, and highly efficient catalysts. Here, we reported the controlled synthesis of ultrafine Co9S8 nanocrystals embedded in N, S-codoped multilayer-assembled carbon nanoplates (Co9S8/NSCP) for highly efficient oxygen electrocatalysis. The bifunctional Co9S8/NSCP electrocatalyst displays a high half-wave potential for ORR, and a low overpotential for OER in 0.1M KOH at a current density of 10 mA cm -2, much better than those of single component counterparts (Co9S8 or carbon) and comparable to noble metal catalysts. The high performance of Co9S8/NSCP can be attributed to the rationally designed hierarchical architecture with nanosized Co9S8 nanocrystals, rich N, S-codopants, highly exposed surface area, and protective graphitic layers, providing abundant active sites with full utilization and stable carbon support towards fast catalytic kinetics and durability. This work will promote further research on the development of highly efficient and stable non-noble metal electrocatalysts for ORR and OER.

Ultralow In-Plane Thermal Conductivity in 2D Magnetic Mosaic Superlattices for Enhanced Thermoelectric Performance.

Lowering thermal conductivity via introducing heterointerfaces of heterophase fillings (HPFs) is a common strategy for optimizing thermoelectric performance, but it is always accompanied by deterioration of electrical conductivity. Here we report an ordered magnetic HPF system in a CoSe2-SnSe mosaic heterostructure superlattice synthesized by van der Waals confined epitaxial growth (vdWCEG), which realizes a maximized filling amount to decrease in-plane thermal conductivity of SnSe layers and maintain the intact in-plane carrier transport path. The in-plane thermal conductivity of CoSe2-SnSe superlattice reaches the lowest range among SnSe-based materials with a value of 0.27 W m-1 K-1 at 850 K, which can be attributed to abundant interfaces between CoSe2 nanocrystals and SnSe layers. Moreover, the CoSe2 nanocrystals show superparamagnetic behavior, by which the rotation of magnetic domains provides additional phonon scattering to further decrease in-plane thermal conductivity. By combination with the preserved in-plane electrical conductivity of SnSe layers, an enhanced in-plane ZT value of 0.62 is achieved at 850 K. This vdWCEG approach can also be generally applied to fabricate various other two-dimensional (2D) mosaic heterostructures, providing an avenue for artificial 2D heterostructures with desired functionalities.

Confined Co9S8 nanocrystals into N/S-Co-doped carbon nanofibers as a chainmail-like electrocatalyst for high-performance lithium-sulfur batteries with high sulfur loading

Accelerating phase transposition efficiency of lithium polysulfides (LiPSs) to L2S and hampering the solution of LiPSs are the keys to stabilizing lithium-sulfur (Li-S) batteries. Hence, the sulfiphilic ultrafine Co9S8 nanoparticles embedded lithiophilic N, S co-doping carbon nanofibers (Co9S8/NSCNF) are prepared via the dual-template method, which are then used as sulfur host in Li-S batteries. Particularly, the double active sites (Co9S8 and N, S) in Co9S8/NSCNF are prone to form “Co-S”, “Li-O” or “Li-N” bonds, and then simultaneously improving the chemisorption and interface transposition capability of LiPSs. In case of the S@ Co9S8/NSCNF composites with high sulfur loading of 89% are employed as cathode, the cell possesses optimized “sulfiphilicity” and “lithiophilicity”, which achieves remarkable sulfur electrochemistry, including outstanding reversibility of 816.8mAhg−1 over 500 cycles at 1.0C, excellent rate property of 742.2mAhg-1at 5.0C, and long-term cycling with a low attenuation of 0.011% per cycle over 1800 cycles at 3.0C. Impressively, a remarkable areal capacity of 11.51mAhcm−2 is retained under the sulfur loading of 15.3 mg cm−2 for 50 cycles. This research will deepen the understanding of the complex LiPSs interface transposition procedure and provide new ideas for the design of new host materials.

Bipolar CoSe2 nanocrystals embedded in porous carbon nanocages as an efficient electrocatalyst for Li-S batteries

The confinement and catalysis properties of orthorhombic CoSe2 as a host material for Li-S battery are studied by theoretical and experimental methods. First-principles calculations show that the (111) surface of CoSe2 possesses adjacent nucleophilic and electrophilic centers. This bi-polar surface can easily bond the polysulfide molecules and catalyze their conversion reactions. As a result, the decomposition energy barriers of polysulfides are greatly decreased from ∼3.0 eV to 0.2–0.4 eV. Following theoretical prediction, CoSe2 nanocrystals with specific (111) surface are prepared and embedded in porous carbon nanocages using ZIF-67 metal organic framework as a template. Benefited from the advantages of porous C and CoSe2 (111) surface, the shuttling of polysulfides is suppressed and their conversion kinetics is facilitated. The Li-S cell using this host material exhibits high capacity and remarkable cycle stability, showing a discharge capacity of 1199 mA·h·g−1 at 0.2C and 400 stable cycles at 1.0C.

Unique Mo2C–CdS–Co@C heterojunction integrated with redox cocatalysts and multiple active sites for efficient photocatalytic H2 generation

Photocatalytic water-splitting has encouraged great interest to obtain renewable H2 fuel via the transformation of solar energy. Although significant progress has been achieved, realizing efficient H2 evolution reaction (HER) with non-noble-metal photocatalysts is still challenging. Herein, we report a facile synthesis of Mo2C–CdS–[email protected] heterojunction by anchoring CdS and Mo2C nanoparticles onto [email protected] micro-flowers. The [email protected] micro-flowers were composed of graphitic carbon nanoflakes partially embedded with Co, CoOx, Co9S8 nanocrystals and obtained through the carbonization of metanilic-anion intercalated Co(OH)2 precursor. Due to excellent visible-light harvesting capacity, efficient charge transmission and isolation caused by the existence of superior electron mediator (graphitic carbon) together with oxidation (CoOx) and reduction (Co, Co9S8, Mo2C) cocatalysts, as well as the plentiful H2-evolving active sites originating from the metal (Co), metal sulfide (Co9S8), and metal carbide (Mo2C), the Mo2C–CdS–[email protected] hybrid micro-flowers delivered an exceptional HER (λ > 400 nm) activity of 760.58 μmol h−1 (10 mg), approximately 32 and 15 folds that of pristine CdS and platinum (3 wt%)-decorated CdS, respectively. Moreover, both the cycling and long-term photocatalytic tests confirm that the Mo2C–CdS–[email protected] possesses an outstanding durability for H2 production. The study results might inspire the rational integration of cocatalysts to simultaneously optimize the charge trapping and H2-evolving kinetics for strengthening the photocatalytic HER activity efficiently.

In situ grown Co9S8 nanocrystals in sulfur-doped carbon matrix for electrocatalytic oxidation of hydrazine

The development of effective and low-cost anode catalysts is a big challenge in the application of direct hydrazine fuel cell (DHFC). Herein, we report the in-situ grown Co9S8 nanocrystals into S-doped carbon matrix (Co9S8@S-C) as an efficient electrocatalyst for hydrazine oxidation reaction (HzOR). Co9S8 nanocrystals serve as the active site for electrocatalytic HzOR, and the conductive and porous S-doped carbon matrix not only promotes the charge and mass transfer, but also immobilizes and protects the Co9S8 nanocrystals from damage during HzOR. The optimal Co9S8@S-C-600 catalyst possesses a high Brunauer-Emmett-Teller (BET) specific surface area of 60.8 m2 g−1, and shows a current density (j) of 376 mA∙cm−2 for HzOR in alkaline medium at 0.3 V vs RHE, whose activity exceeds that of some previously reported electrocatalysts for HzOR. Furthermore, the activity retention rate of Co9S8@S-C-600 is 92.8% after 12 h HzOR test at a j value of greater than 300 mA∙cm−2, which is much better than that of Pt/C catalyst (15% activity retention). The excellent activity and durability of the Co9S8@S-C-600 catalyst are mainly attributed to the combined effect of highly active Co9S8 nanocrystals and the conductive and porous S-doped carbon matrixes, which makes Co9S8@S-C-600 as an effective non-noble metal electrocatalysts for HzOR.

A bifunctional nanozyme of carbon dots-mediated Co9S8 formation

Controlling the size of nanocrystals and inhibiting their agglomeration are of paramount importance for achieving ideal catalytic performance. Here we discovered that carbon dots (CDs) are not only able to serve as reductants but also as stabilizers of ultrasmall Co9S8 nanocrystals by means of their surface terminal groups. As a result, ultrasmall Co9S8 nanocrystals are incorporated into porous carbon nanosheets formed by splicing CDs. The resultant nanocomposites display a rich pore structure accompanying with large specific surface area and outstanding bifunctional performances to mimic the catalytic activity of peroxidase and oxidase without exerting any external energy. More importantly, the unique architecture endows Co9S8 nanocrystals with high stability and good durability. The nanocomposites have been demonstrated as a colorimetric sensor for detection of ascorbic acid with a superior anti-interference ability as well as a detection limit of 0.2 μM. Our findings open new synthetic opportunities by tuning the interaction of CDs with the surrounding environment and enable advanced applications such as biomedicine and catalytic transformations.

Shape and nanocrystal transformations

Nanomaterials Cation exchange reactions that change the composition of a nanocrystal (NC) under mild conditions usually preserve the sublattice of the larger anions. Li et al. found that the shape of roxbyite (Cu1.8S) nanocrystals, which have a distorted, hexagonal, close-packed sulfide anion sublattice, affected the outcome of exchange reactions with cobalt ions. Flat nanoplates retained the anion lattice and formed cobalt sulfide, but tall nanorods transformed into Co9S8 nanocrystals with a cubic, close-packed structure. Facile crystal plane sliding in the taller nanocrystals appears to have driven the different layer stacking of sulfide anions. Science , abh2741, this issue p. [332][1] [1]: /lookup/doi/10.1126/science.abh2741

N‐doped carbon‐coated CoSe 2 nanocrystals anchored on two‐dimensional MXene nanosheets for efficient electrochemical sodium‐ and potassium‐ion storage

Sodium-ion batteries (SIBs) and potassium-ion batteries (KIBs) have received much attention as next-generation energy storage systems owing to the abundance. Nevertheless, they face great challenges in the design of optimum electrode materials for practical applications. Herein, we prepared a unique two-dimensional structured composite consisting of N-doped carbon-coated CoSe2 nanocrystals and MXene nanosheets (CoSe2@NC/MX) for efficient electrochemical Na- and K-ion storage. In this strategy, a Co-based zeolitic imidazole framework (ZIF-67) was deposited on the surface of MXene nanosheets, and the subsequent selenization process resulted in the transformation of the ZIF-67 into CoSe2@NCs. The unique structure can shorten the transport pathways for electrons/ions and provide sufficient space to accommodate the volume change of the active materials. Furthermore, the N-doped carbon matrix and MXene can enhance the robustness of the electrode materials. Accordingly, the composites exhibited enhanced electrochemical performance in terms of cycle stability (317 mA h g−1 after 200 cycles at 0.5 A g−1) and rate capability (343 mA h g−1 at 7.0 A g−1) for SIBs. For KIBs, they exhibited a high reversible capacity of 358 mA h g−1 at 0.5 A g−1 after 100 cycles and 276 mA h g−1 at a high rate of 2.0 A g−1.

Encapsulating Co9S8 nanocrystals into CNT-reinforced N-doped carbon nanofibers as a chainmail-like electrocatalyst for advanced Li-S batteries with high sulfur loading

Li-S batteries have been regarded as one promising candidate for next-generation energy storage systems, however, their practical implementations are severely hindered by the intractable polysulfides shuttle (PSS) effect and retarded conversion kinetics. Herein, a flexible electrode consisting of Co9S8 nanocrystals and CNTs encapsulated inside porous N-doped carbon nanofibers (NCF) (CNT@NC/Co9S8) was developed by electrospinning followed by in-situ sulfurization. The carbon nanofibers and embedded CNTs build a highly conductive network, while the Co9S8 and N dopant provide more polar sites for LiPSs confinement. This self-supported flexible electrode with a sulfur loading of 12.5 mg cm−2 exhibits a high initial discharge capacity (1207.7 mAh g−1 at 0.1C), excellent rate capability (831.2 mAh g−1 at 4.0C) and cycling stability (765.5 mAh g−1 with a capacity retention of 78.1% after 1000 cycles at 2.0C). Moreover, when the sulfur loading increases to 20 and 30 mg cm−2, high capacities of 869.2 and 706.6 mAh g−1can still be obtained at 0.1C after 100 cycles, respectively. Theoretical analysis suggests that the sulfur cathode built on CNT@NC/Co9S8 is electrocatalytically active towards LiPSs redox with enhanced conversion dynamics, thus mitigating the detrimental PSS effect.