Three-dimensional Open Structure Research Articles

Copper and nickel hexacyanoferrates/carbon nanotube nanocomposites thin films as high-performance light cathode materials for aqueous sodium-ion batteries

Aqueous rechargeable Na-ion batteries are gaining popularity as an attractive alternative for energy storage systems due to their low cost, wide range of raw material sources, non-flammability, and ultrahigh ionic conductivity. Currently, Because of their three-dimensional open structure, high specific capacity, and inexpensive cost, Prussian blue analogues are being investigated as electrode materials for electrochemistry. In this work, we present an innovative strategy to create novel two-component nanoarchitected thin films that exhibit exceptional performance as cathodes in aqueous sodium-ion batteries (SIBs). By leveraging the versatility of the liquid-liquid interfacial method, we have prepared two distinct transparent nanocomposite films composed of carbon nanotubes and either copper or nickel hexacyanoferrate nanoparticles. The results show that the NiHCF/CNT and CuHCF/CNT deliver a high specific capacity of 152 mA h g−1 and 135 mA h g−1, respectively, at a high current density of 1 A g−1. Moreover, the cells (rGO//NiHCF and rGO//CuHCF) show that the energy density of the battery can reach up to 7.75 Wh kg−1 at a power density of 27.92 W kg−1 for rGO//NiHCF/CNT, while rGO//CuHCF/CNT showed an energy density of 3.67 Wh kg−1 at a power density of 13.21 W kg−1. The results demonstrate that NiHCF/CNT and CuHCF/CNT nanocomposite films provide new insight into the design of high-performance PBA cathodes.

Hf-Doped CoP Hollow Nanocubes as High-Performance Electrocatalyst for Oxygen Evolution Reaction.

Designing and synthesizing hollow frame structures with unique three-dimensional open structures in electrocatalysis remain a challenge. Etching is an effective method to synthesize metal-organic frameworks (MOFs) with a hollow structure and rich function. Herein, we report the design and synthesis of Hf-doped CoP hollow nanocubes by selective etching and ion exchange. Different from the traditional etching method, we used acid xylenol orange solution to etch typically the (211) crystal face of ZIF-67, obtaining the unique bell-like structure, named XO-ZIF-67. Subsequently, Hf-doped CoP hollow nanocubes were formed by Hf4+ doping and simple phosphating treatment. Electrochemical tests showed that the overpotential of the obtained catalyst is only 291 mV at the current density of 10 mA cm-2 when applied in catalyzing the oxygen evolution reaction (OER). Furthermore, the catalyst shows excellent stability when running in 1 M KOH solution for 25 h.

In vitro digestion of starch and protein aerogels generated from defatted rice bran via supercritical carbon dioxide drying

This study investigated the in vitro digestibility of starch and protein aerogels produced from defatted rice bran (DRB), an underutilized rice processing byproduct, using supercritical carbon dioxide (SC-CO2) drying. The extracted starch (i.e., purified starch), crude starch, and proteins were used for the aerogel formation at 15% (w/w) concentration and further characterized. All aerogels exhibited three-dimensional open porous structures with high surface areas of 36–47 m2/g, densities lower than 0.3 g/cm3, and porosities higher than 84%. The starch hydrolyses in starch and crude starch aerogels were 86 and 73%, respectively, while the protein hydrolysis in protein aerogels reached up to 82% after sequential oral, gastric, and intestinal digestion. Thus, the hydrolysis rates achieved in simulated digestions suggest that the developed aerogels from DRB have the potential to serve as vehicles for delivering bioactive compounds and add value to the underutilized DRB.

Nanoporous Nickel Cathode with an Electrostatic Chlorine-Resistant Surface for Industrial Seawater Electrolysis Hydrogen Production.

Seawater electrolysis presents a promising avenue for green hydrogen production toward a carbon-free society. However, the electrode materials face significant challenges including severe chlorine-induced corrosion and high reaction overpotential, resulting in low energy conversion efficiency and low current density operation. Herein, we put forward a nanoporous nickel (npNi) cathode with high chlorine corrosion resistance for energy-efficient seawater electrolysis at industrial current densities (0.4-1 A cm-2). With the merits of an electrostatic chlorine-resistant surface, modulated Ni active sites, and a robust three-dimensional open structure, the npNi electrode showed a low hydrogen evolution reaction overpotential of 310 mV and a high electricity-hydrogen conversion efficiency of 59.7% at 400 mA cm-2 in real seawater and outperformed most Ni-based seawater electrolysis cathodes in recent publications and the commercial Ni foam electrode (459 mV, 46.4%) under the same test condition. In situ electrochemical impedance spectroscopy, high-frame-rate optical microscopy, and first-principles calculation revealed that the improved corrosion resistance, enhanced intrinsic activity, and mass transfer were responsible for the lowered electrocatalytic overpotential and enhanced energy efficiency.

In-situ coupling of N-doped carbon dots with manganese hexacyanoferrate as a cathode material for aqueous zinc-ion batteries

Prussian blue analogs (PBAs) are a competitive class of aqueous Zn-ion batteries (AZIBs) cathode materials with an ideal three-dimensional open structure for rapid insertion and removal of Zn2+. Meanwhile, PBAs have the advantages of high working voltage and a simple synthesis process. However, these materials are inherently poor in electrical conductivity and are susceptible to structural collapse during cycling. These defects affect the performance of zinc storage in this type of material. Here, the integration of zero-dimensional nitrogen-doped carbon dots (NCDs) and in-situ grown manganese hexacyanoferrate (MnHCF) affords the MnHCF/NCDs cathode materials, which are applied to AZIBs. The introduction of NCDs modifies the active component of MnHCF effectively. Meanwhile, NCDs significantly enhance the overall electrical conductivity and structural stability of the composites and also provide abundant active sites for electrochemical reactions. Benefiting from these merits, the MnHCF/NCDs composite exhibits an excellent electrochemical zinc storage performance. It has a high discharge-specific capacity of 131.2 mAh g−1 at 50 mA g−1 and has outstanding cycling stability of 91% capacity retention after 1000 cycles at 1000 mA g−1. The electrochemical performance of PBAs-based cathodes for AZIBs may be improved using the straightforward and efficient method presented in this work.

Effectively morphology-controlled NiMn layered double hydroxide microflowers by conductive silver nanowires for supercapacitor electrodes

Effective ion and electron transport pathways provide an effective method to further improve the energy storage performance of layered double hydroxide (LDH) for supercapacitors. Here, microflower-like NiMn LDH/silver nanowires (Ag NWs) composites for high-performance supercapacitors are constructed by a convenient hydrothermal method, in which silver nanowires are found to not only ensure excellent electron conductivity but also have a positive effect on the growth of LDH nanosheets to form the unique three-dimensional open pore structure. In addition, the significantly increased interlayer spacing of the composite enables fast ion transport. In particular, NiMn LDH/Ag NWs exhibits higher specific capacitance (1436.30 F·g−1 at 2 A·g−1) in a three-electrode system, which is 121.29% of the specific capacitance of pure NiMn LDH. The asymmetric supercapacitor assembled with NiMn LDH/Ag NWs and AC electrode exhibits high specific capacitance of 215.63 F·g−1 at 2 A·g−1, superior energy density of 71.95 Wh·kg−1 and excellent cycling stability, illustrating that the NiMn LDH/Ag NWs composite is the promising material for supercapacitor applications.

Preparation of Hexagonal Boron Nitride-Containing Foam with Improved Thermal Conductivity of Epoxy Resins

With the continuous development of electrical and electronic devices, the thermal conductivity of dielectric polymer composites within devices is becoming increasingly important. However, improving the thermal conductivity usually requires the incorporation of a large amount of filler in polymer material, which undoubtedly increases the production cost while destroying the processability and the dielectric properties of the material. In this work, an efficient heat transfer network was constructed inside the resin matrix to overcome this drawback. Using the opposite surface potentials of hexagonal boron nitride (h-BN) and polyethyleneimine (PEI) in solvent, h-BN was anchored on the surface of melamine foam (MF) by an electrostatic self-assembly technique to construct a thermal conductive skeleton with a three-dimensional open pore structure, and the corresponding epoxy (EP) composite was prepared by vacuum-assisted impregnation. This EP–MF@BN composite showed a significant increase in the heat arrival rate at an extremely low filler loading. At a h-BN loading of 2.1 wt %, the thermal conductivity of the composite reached 0.433 W/(m·K), which was 147% higher than that of the pure resin matrix. This is mainly attributed to the unique three-dimensional open-hole structure of the MF foam, which formed a three-dimensional frame structure with extremely low thermal resistance after anchoring by h-BN, thus providing a great degree of weakening of the scattering behavior during phonon transport. In addition, the transport behavior of carriers inside the composite under strong electric field conditions was analyzed in the current study. This strategy of constructing an efficient heat transfer network inside the polymer matrix provides an idea and method for the preparation of composites in the field of electrical insulation.

Interfacial Engineering of Leaf-like Bimetallic MOF-Based Co@NC Nanoarrays Coupled with Ultrathin CoFe-LDH Nanosheets for Rechargeable and Flexible Zn-Air Batteries.

Exploring high-efficiency, low-cost, and long-life bifunctional self-supporting electrocatalysts is of great significance for the practical application of advanced rechargeable Zn-air batteries (ZABs), especially flexible solid-state ZABs. Herein, ultrathin CoFe-layered double hydroxide (CoFe-LDH) nanosheets are strongly coupled on the surface of leaf-like bimetallic metal-organic frameworks (MOFs)-derived hybrid carbon (Co@NC) nanoflake nanoarrays supported by carbon cloth (CC) via a facile and scalable method for rechargeable and flexible ZABs. This interfacial engineering for CoFe-LDHs on Co@NC improves the electronic conductivity of CoFe-LDH nanosheets as well as achieves the balance of oxygen evolution reduction (OER) and oxygen reduction reaction (ORR) activity. The unique three-dimensional (3D) open interconnected hierarchical structure facilitates the transport of substances during the electrochemical process while ensuring adequate exposure of OER/ORR active centers. When applied as an additive-free air cathode in rechargeable liquid ZABs, CC/Co@NC/CoFe-LDH-700 demonstrates high open-circuit potential of 1.47 V, maximum power density of 129.3 mW cm-2, and satisfactory specific capacity of 710.7 mAh g-1Zn. Further, the flexible all-solid-state ZAB assembled by CC/Co@NC/CoFe-LDH-700 displays gratifying mechanical flexibility and stable cycling performance over 40 h. More significantly, the series-connected flexible ZAB is further verified as a chain power supply for LED strips and performs well throughout the bending process, showing great application prospects in portable and wearable electronics. This work sheds new light on the design of high-performance self-supporting non-precious metal bifunctional electrocatalysts for OER/ORR and air cathodes for rechargeable ZABs.

Hierarchical Nickel–Cobalt Hydroxide Composite Nanosheets-Incorporated Nitrogen-Doped Carbon Nanotubes Embedded with Nickel–Cobalt Alloy Nanoparticles for Driving a 2 V Asymmetric Supercapacitor

A class of electrode materials with favorable structures and compositions and powerful electrochemical (EC) properties are needed to boost the supercapacitor capacity significantly. In this study, an inventive technique was established to produce a well-aligned nickel-cobalt alloy nanoparticles-encapsulated N-doped carbon nanotubes with porous structure and good conductivity on carbon cloth (NiCo@NCNTs/CC) as a substrate. Then, nanosheets of nickel-cobalt layered double hydroxide (NiCo-LDH) were grown on NiCo@NCNTs/CC via a simple EC deposition method to construct a self-supported monolithic hierarchical nanosheets/nanotubes composite electrode of NiCo-LDH/NiCo@NCNTs/CC. In such a composite electrode, the NiCo@NCNTs can act as a good conductor and structural scaffold to grow NiCo-LDH nanosheets with a three-dimensional open and porous structure, which helps to improve the electron/ion-transfer performance, increase the number of exposed reactive sites, and inhibit the aggregation of NiCo-LDH nanosheets, thereby boosting the capacitance and stability. As a positive electrode, the NiCo-LDH/NiCo@NCNTs/CC hierarchical nanosheets/nanotubes electrode displays 1898 mF cm-2 (1262 A g-1) of high capacitance, long-term stability with a capacitance retention of around 100% after 8000 cycles, and nearly 103% Coulombic efficiency. After assembling into an asymmetric supercapacitor with a Co(OH)2/NiCo@NCNTs/CC negative electrode, 2 V of operating voltage with 73.1 μW h cm-2 (52.8 W h kg-1) of energy density was achieved. Our investigation gives a potential approach for constructing the integrated composite electrode of transition-metal compounds-carbon materials for high-performance supercapacitors.

The recent advances of NASICON-Na3V2(PO4)3 cathode materials for sodium-ion batteries

NASICON (super ionic conductor)-type Na3V2(PO4)3 (NVP) has been widely studied as a very promising cathode material for sodium-ion batteries (SIBs) due to its high theoretical specific capacity, high voltage platform, good chemical stability, its unique three-dimensional (3D) open crystal structure, and the de/intercalation of sodium ions during charge/discharge. However, the high Na+ diffusion ability of NVP is accompanied by the large bulk structure and poor electronic conductivity, which leads to poor electrochemical performance in terms of rate capability and cycling stability and thus impedes its practical application. Herein, the research development of NVP sodium ion cathode materials are reviewed in recent years. Based on the crystal structure and ion migration mechanism of NVP materials, the sodium storage mechanism and theoretical capacitance of NVP materials are introduced, and the effects of different preparation methods on the electrochemical properties of NVP materials are summarized and compared. The modification research strategies to improve the electrochemical performance of NVP electrode materials are mainly discussed, including carbon material modification, ion doping, and material Nano-crystallization. Finally, some remarks are made on the challenges and prospects for the future development of NVP cathodes.

Sodium vanadium hexacyanoferrate as a high-rate capability and long-life cathode material for Na-ion batteries

Na-ion batteries have gradually begun to be commercialized due to their advantages of lower cost and wide source of raw materials, but more excellent electrochemical performance is required to compete with lithium-ion batteries. In this work, sodium vanadium hexacyanoferrate (NaVHCF) was designed and synthesized as a Na-ion cathode material to exhibit excellent electrochemical performance. The results show that the capacity retention rate of 1000 cycles at 2.5C rate is 72 %, the Coulombic efficiency is 100 %, and the capacity retention rate of 5000 cycles at 25C high rate is 65 %. After activating at a low current density of 2.5C, it still has a capacity of 42 mAh g−1 after 2000 cycles at a high rate of 25C, and the capacity retention rate is 92 %. The analysis shows that the excellent rate and long cycling ability are related to the three-dimensional open structure and microporous structure of NaVHCF. During the long cycle, the diffusion coefficient of sodium ions gradually increases and the charge transfer resistance gradually decreases, which improves the battery lifespan. These results suggest that sodium-ion batteries are one step closer to commercial application.

Self-standing reduced graphene oxide/Nb2C MXene paper electrode with three-dimensional open structure for high-rate potassium ion storage

Potassium ion battery (PIBs) is in the primary stage of development, exploring appropriate electrode materials is the key to obtain high performance and practical application. Herein, we design a self-standing reduced graphene (rGO) and Nb2C MXene (3D-rGO/Nb2C) composite paper electrode with three-dimensional porous conductive network by electrostatic absorption self-assembly method. Compared with the compact structure of L-rGO/Nb2C paper electrode via layer-by-layer vacuum filtration approach, the structure design in which the wrinkled rGO is applied as the framework provides a large number of surface active sites and promotes the rapid transfer of K+ to improve the storage capacity and kinetics of potassium ions. Moreover, the 3D-rGO/Nb2C hybrid paper with large specific surface area can effectively accommodate the volume expansion during charging and discharging process and ensure the cycle stability. At current density of 500 mA g−1, the 3D-rGO/Nb2C hybrid paper electrode delivers an initial capacity of 207 mAh·g−1, which is maintained at 139 mAh·g−1 after 1000 cycles. The 3D-rGO/Nb2C hybrid paper combines both diffusion mechanism and pseudo-capacitance mechanism, which significantly improves its electrochemical performance in K-ion storage. These results show the good potential of the 3D-rGO/Nb2C hybrid paper as a high-performance electrode.

Superlative photoelectrochemical properties of 3D MgCr-LDH nanoparticles influencing towards photoinduced water splitting reactions

In the present work, we report the synthesis of single system three-dimensional (3D) open porous structure of MgCr-LDH nanoparticles in a substrate-free path by using one-step formamide assisted hydrothermal reaction followed by visible light irradiation for significant photoelectrochemical (PEC) properties that manifest towards photocatalytic H2 and O2 production. The as-prepared nanostructured materials were characterized by various physico-chemical characterization techniques. Moreover, this unique synthetic approach produces 3D open porous network structure of MgCr-LDH nanoparticles, which were formed by stacking of numerous 2D nanosheets, for effective light harvestation, easy electronic channelization and unveil superlative PEC properties, including high current density (6.9 mA/cm2), small Tafel slope of 82 mV/decade, smallest arc of the Nyquist plot (59.1 Ω cm−2) and photostability of 6000 s for boosting water splitting activity. In addition, such perfectly self-stacked 2D nanosheets in 3D MgCr-LDH possess more surface active defect sites as enriched 50% oxygen vacancy resulting a good contact surface within the structure for effective light absorption along with easy electron and hole separation, which facilitates the adsorption of protons and intermediate for water oxidation. Additionally, the Cr3+ as dopant pull up the electrons from water oxidation intermediates, thereby displaying superior photocatalytic H2 and O2 production activity of 1315 μmol/h and 579 μmol/h, respectively. Therefore, the open 3D morphological aspects of MgCr-LDH nanoparticles with porous network structure and high surface area possess more surface defect sites for electron channelization and identified as distinct novel features of this kind of materials for triggering significant PEC properties, along with robustly enhance the photocatalytic water splitting performances.

A facile strategy for developing uniform hierarchical Na3V2(PO4)2F3@carbonized polyacrylonitrile multi-clustered hollow microspheres for high-energy-density sodium-ion batteries

Na superionic conductor structured Na3V2(PO4)2F3 (NVPF) has received considerable attention as a cathode material for sodium-ion batteries because of its higher energy density and three-dimensional open structure for Na+ diffusion channels. However, its insulating structure [PO4] results in significantly inferior conductivity, which severely limits the electrochemical performance of NVPF. In this study, uniform carbonized polyacrylonitrile-coated hierarchical Na3V2(PO4)2F3 multi-clustered hollow microspheres (NVPF-H@cPAN) were synthesized via a facile ethylene glycol-assisted hydrothermal approach, followed by a wet chemical method and heat treatment. Further, the possible formation mechanism of hierarchical Na3V2(PO4)2F3 multi-clustered hollow microspheres was investigated. The concentration of ethylene glycol and hydrothermal reaction time were found to play essential roles in the formation mechanism of the microspheres. The as-prepared NVPF-H@cPAN delivered a high discharge capacity of 116.2 mAh g−1 at 0.2C and impressive cycling stability of 85% at 5C after 2000 cycles. When assembled as NVPF-H@cPAN||commercial hard carbon (NVPF-H@cPAN||CHC) for sodium-ion full cells, which demonstrates a specific capacity of 107 mAh g−1 at 0.2C, thus achieving an energy density of 376.4 Wh kg−1 at a power density of 141 W kg−1. These results can be attributed to the structural regulation of multi-level clusters, which improved the Na+ diffusion rate and carbon coating strategy. Such a combination of structural regulation and carbon-coating strategy can provide a strategy to synthesize materials with multi-level clusters of hollow microspheres to increase the electronic conductivity and enhance the electrochemical performance of energy-storage devices.

Maximizing the enzyme immobilization of enzymatic glucose biofuel cells through hierarchically structured reduced graphene oxide

The number of immobilized glucose oxidase (GOx) molecules is considerably increased by the structural modification of reduced graphene oxide (rGO), and the performance of enzymatic biofuel cells (EBFCs) is positively affected by the modification process. To do this, new rGO with three-dimensional open porous structure is formed by spray freeze drying method (sprGO), while tetrathiafulvalene (TTF) as mediator, and GOx are sequentially immobilized onto sprGO. To improve the loading amount of catalyst, rGO structure is modified to open porous sprGO structure possessing numerous anchoring sites, after which gelatin film crosslinked by glutaraldehyde is fabricated onto sprGO to prevent any losses of other components (sprGO/[TTF-GOx]/crosslinked-gelatin). Specific surface area and charge transfer resistance of sprGO are quantitatively measured, and the actual amount of immobilized GOx and the performance of EBFC using this catalyst are electrochemically examined. With this, it is found that the amount of GOx immobilized in sprGO/[TTF-GOx]/crosslinked-gelatin is twice better that in rGO/[TTF-GOx]/crosslinked-gelatin. More specifically, EBFC using this catalyst shows open circuit voltage of 0.85 V and maximum power density of 380 μW/cm2, and this is 1.4 times better than that using rGO/[TTF-GOx]/crosslinked-gelatin. These results indicate that the amount of immobilized GOx strongly affects the performance capabilities of EBFCs.

Three-dimensional FeP nanotube arrays fabricated through electrostatic-repulsion-limited-nucleation strategy for high-efficiency hydrogen evolution

It is highly desirable but still challenging to construct three-dimensional (3D) open porous structure assembled with small-sized and hollow active components for hydrogen evolution reaction (HER). Here, we propose a novel protocol based on electrostatic-repulsion-limited-nucleation strategy and the nanoscale Kirkendall effect to grow FeP nanotube arrays on P-doped graphene. Due to its unique structural features, the resulting electrocatalyst exhibits superior HER activity with an overpotential of 69 mV at the current density of 10 mA cm−2 in 0.5 M H2SO4, comparable to the benchmark Pt/C catalyst. Furthermore, the 3D porous structure shows robust stability toward HER with a negligible current loss after continuous catalysis over 40 h at 10 mA cm−2. The experimental results and density functional theory calculations indicate that the excellent HER activity of the 3D porous structure originates from its increased active sites, reduced transfer resistance and the ideal hydrogen adsorption energy (ΔGH*), as well as better hydrophily upon integration of FeP nanotubes with P-doped graphene. Our protocol provides a new approach to rationally design and fabricate inexpensive 3D open porous structure with high catalytic activity and robust stability for HER.

Laboratory investigation of powder deflagration flame propagation and quenching behaviors suppressed by ZrO2 ceramic foam

Ceramic foam, with its complex three-dimensional open porous structure, is a promising material for explosion suppression. To assess the suppression effect of ceramic foam on powder deflagration flames, tests were conducted in a vertical quartz tube. Results show that the position of ZrO2 ceramic foam affects coal powder flame propagation behaviors. Compared with conditions in an empty tube, ceramic foam can reduce the pulsation amplitude of flame propagation velocity and acceleration, but ceramic foam which is very close to the ignition source will increase the pulsation amplitude in the initial stage of deflagration to a certain extent. The ceramic foam has a good quenching effect on powder deflagration flames. Ceramic foam can dissipate deflagration energy and block burning and unburned powder, so that the flame will be interrupted due to the loss of fuel supply. The results are of significance to the prevention and control of powder deflagration hazards.

A bifunctional hexa-filamentous microfibril multimetallic foam: an unconventional high-performance electrode for total water splitting under industrial operation conditions

Cellulose in various forms possesses high strength, low density, and high aspect ratio with a three-dimensional open network structure, making them ideal candidates as current collectors in energy conversion application.

CoP nanoprism arrays: Pseudocapacitive behavior on the electrode-electrolyte interface and electrochemical application as an anode material for supercapacitors

The self-supported transition metal phosphide with specific morphology and architecture has been investigated extensively due to excellent conductivity, stability, and morphologic diversity. In the work, cobalt phosphide with special nanoprism arrays in-situ grown on the nickel foam skeleton forms a typical three-dimensional open structure. It exhibits notable electrochemical performance when employed as an anode in a single electrode system, which owns a high mass specific capacitance (1349 F g−1 at the current density of 1 A g−1, which is the highest compared with that in the extant literature), good rate capacity and cycle stability. Besides, pseudocapacitive contribution to the entire capacity is up to about 77%, revealing the nature of high mass specific capacitance of the as-prepared CoP@NF as the working electrode. Furthermore, an asymmetrical supercapacitor device has been fabricated using CoP@NF as an anode and CMK-3@NF as a cathode. It can deliver a high power density of 325 W kg−1 at the energy density of 24 Wh kg−1 and the specific capacitance retention of about 93% after 5000 cycles. The results demonstrate that CoP@NF with special nanoprism arrays is a promising potential candidate as the electrode material of supercapacitors and other energy-storing applications.

Co9S8 Nanorods as an Electrocatalyst To Enhance Polysulfide Conversion and Alleviate Passivation in Li-S Batteries under Lean Electrolyte Conditions.

As a result of the high theoretical energy density of lithium-sulfur (Li-S) batteries, they have been accepted as the next-generation energy storage system. Nevertheless, the current performance of Li-S batteries is still unsatisfactory under lean electrolyte conditions. It is because of sluggish deposition of Li2S2/Li2S passivating the sulfur/electrolyte interface, thus leading to lower sulfur use and bad rate performances of Li-S batteries. Herein, a novel Co9S8 nanorod-based catalytic interlayer placed between the cathode and separator is proposed. The interlayer possesses a three-dimensional open structure, which facilitates electrolyte infiltration but without trapping too much electrolyte. As a result, the electrocatalytic Co9S8 nanorods within the interlayer promote faster electrochemical kinetics and enhance the conversion of polysulfides, thus resulting in a higher specific discharge capacity and better rate and cycling performance. This work proves a feasible method in developing practical Li-S batteries.