Sulfur In Cathode Research Articles

Nitrogen-Doped Carbon and Metal-Nitrogen-Carbon Materials as Cathode Hosts for Li-S Batteries: Experimental Study and Mechanism Analysis.

Both nitrogen-doped carbon (NC) and metal-nitrogen-carbon (MNC) materials have been extensively investigated in lithium-sulfur batteries to alleviate the "shuttle effect". MNC are generally synthesized using NC as the parent material, wherein nitrogen atoms in NC serve as the "bridge" to coordinate with metal atoms. So far, an important scientific issue has not been settled: does the introduction of metal sites into NC certainly enhance the Li-S battery performance? In this work, NC and MNC materials derived from the same precursor, a nitrogen-rich porous polymer, are systematically compared as cathode hosts for Li-S battery through theoretical calculations and experimental investigation. Li-S cell with NC as the cathode sulfur host exhibits better cycle performance at low current densities (0.1 and 0.2C), whereas MNC materials predominate at higher current densities (such as 1C and 2C). Based on theoretical calculation and experimental results, it is concluded that the introduction of metal sites into NC through nitrogen bonding promoted the catalytic capability for faster sulfur redox reaction kinetics, whereas the adsorption energy toward polysulfides decreased. This work provides important guidance for more targeted design of advanced materials for lithium-sulfur battery application in the future.

Hollow Defect-Rich Nanofibers as Sulfur Hosts for Lithium-Sulfur Batteries.

The slow redox kinetics of lithium-sulfur batteries severely limit their application, and sulfur utilization can be effectively enhanced by designing different cathode sulfur host materials. Herein, we report the hollow porous nanofiber LaNi0.6Co0.4O3 as a bidirectional host material for lithium-sulfur batteries. After Co is substituted into LaNiO3, oxygen vacancies are generated to enhance the material conductivity and enrich the active sites of the material, and the electrochemical reaction rate can be further accelerated by the synergistic catalytic ability of Ni and Co elements in the B-site of the active site of LaNi0.6Co0.4O3. As illustrated by the kinetic test results, LaNi0.6Co0.4O3 effectively accelerated the interconversion of lithium polysulfides, and the nucleation of Li2S and the dissolution rate of Li2S were significantly enhanced, indicating that LaNi0.6Co0.4O3 accelerated the redox kinetics of the lithium-sulfur battery during the charging and discharging process. In the electrochemical performance test, the initial discharge specific capacity of S/LaNi0.6Co0.4O3 was 1140.4 mAh g-1 at 0.1 C, and it was able to release a discharge specific capacity of 584.2 mAh g-1 at a rate of 5 C. It also showed excellent cycling ability in the long cycle test, with a single-cycle capacity degradation rate of only 0.08%. Even under the harsh conditions of high loaded sulfur and low electrolyte dosage, S/LaNi0.6Co0.4O3 still delivers excellent specific capacity and excellent cycling capability. Therefore, this study provides an idea for the future development of bidirectional high-activity electrocatalysts for lithium-sulfur batteries.

Multifunctional Vanadium Nitride-Modified Separator for High-Performance Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSBs) are recognized as among the best potential alternative battery systems to lithium-ion batteries and have been widely investigated. However, the shuttle effect has severely restricted the advancement in their practical applications. Here, we prepare vanadium nitride (VN) nanoparticles grown in situ on a nitrogen-doped carbon skeleton (denoted as VN@NC) derived from the MAX phase and use it as separator modification materials for LSBs to suppress the shuttle effect and optimize electrochemical performance. Thanks to the outstanding catalytic performance of VN and the superior electrical conductivity of carbon skeleton derived from MAX, the synergistic effect between the two accelerates the kinetics of both lithium polysulfides (LiPSs) to Li2S and the reverse reaction, effectively suppresses the shuttle effect, and increases cathode sulfur availability, significantly enhancing the electrochemical performance of LSBs. LSBs constructed with VN@NC-modified separators achieve outstanding rate performance and cycle stability. With a capacity of 560 mAh g-1 at 4 C, it exhibits enhanced structural and chemical stability. At 1 C, the device has an incipient capacity of 1052.4 mAh g-1, and the degradation rate averaged only 0.085% over 400cycles. Meanwhile, the LSBs also show larger capacities and good cycling stability at a low electrolyte/sulfur ratio and high surface-loaded sulfur conditions. Thus, a facile and efficient way of preparing modified materials for separators is provided to realize high-performance LSBs.

Nickel aerogel @ ultra-thin NiCo-LDH nanosheets integrated freestanding film as a collaborative adsorption and accelerated conversion cathode to improve the rate performance of lithium sulfur batteries

It is a great challenge to develop freestanding ultralight cathodes for lithium–sulfur battery exhibiting good electrochemical performances. Herein, ultrathin porous nickel–cobalt layered double hydroxide (NiCo-LDH) nanosheets were grown on the surface of ultra-light nickel microwire aerogels (NMWAs), and there is capillary action in the gaps formed by the ordered arrangement due to the presence of magnetic filed in the preparation process, which has the advantages of synergistic adsorption and accelerated conversion kinetics of lithium polysulfide. Because of the abundant hydrophilic hydroxyl groups on the surface of NiCo-LDH and the capillary action of NMWAs, the integrated freestanding film cathode sulfur host (NMWAs@NiCo-LDH/S) provides excellent rate performance as well as cycling stability. The film cathode has an ultra-high initial specific capacity of 1238.4 mAh g−1 at 0.1C and an excellent reversible capacity of 805.8 mAh/g at 5.0C. Even after 700 cycles at a high current density of 5.0C, it still provides a reversible capacity of 647.1 mAh g−1 with a capacity decay rate of only 0.018 % per cycle. This work provides a simple and new way for the design of high rate lithium–sulfur battery film cathodes with good cycle stability.

A High-Energy Aqueous All-Sulfur Battery.

Rechargeable aqueous batteries are promising energy storage devices because of their high safety and low cost. However, their energy densities are generally unsatisfactory due to the limited capacities of ion-inserted electrode materials, prohibiting their widespread applications. Herein, a high-energy aqueous all-sulfur battery was constructed via matching S/Cu2 S and S/CaSx redox couples. In such batteries, both cathodes and anodes undergo the conversion reaction between sulfur/metal sulfides redox couples, which display high specific capacities and rational electrode potential difference. Furthermore, during the charge/discharge process, the simultaneous redox of Cu2+ ion charge-carriers also takes place and contributes to a more two-electron transfer, which doubles the capacity of cathodes. As a result, the assembled aqueous all-sulfur batteries deliver a high discharge capacity of 447 mAh g-1 based on total mass of sulfur in cathode and anode at 0.1 A g-1 , contributing to an enhanced energy density of 393 Wh kg-1 . This work will widen the scope for the design of high-energy aqueous batteries.

A High‐Energy Aqueous All‐Sulfur Battery

AbstractRechargeable aqueous batteries are promising energy storage devices because of their high safety and low cost. However, their energy densities are generally unsatisfactory due to the limited capacities of ion‐inserted electrode materials, prohibiting their widespread applications. Herein, a high‐energy aqueous all‐sulfur battery was constructed via matching S/Cu2S and S/CaSx redox couples. In such batteries, both cathodes and anodes undergo the conversion reaction between sulfur/metal sulfides redox couples, which display high specific capacities and rational electrode potential difference. Furthermore, during the charge/discharge process, the simultaneous redox of Cu2+ ion charge‐carriers also takes place and contributes to a more two‐electron transfer, which doubles the capacity of cathodes. As a result, the assembled aqueous all‐sulfur batteries deliver a high discharge capacity of 447 mAh g−1 based on total mass of sulfur in cathode and anode at 0.1 A g−1, contributing to an enhanced energy density of 393 Wh kg−1. This work will widen the scope for the design of high‐energy aqueous batteries.

Configuring a O,S-doped carbon substrate as sulfur anchor for Li–S batteries

Configuring a carbon substrate with low surface polarity seems very important and significant for accelerating the cathode electrochemical performances of the Lithium-sulfur batteries, which is widely regarded as one of the most promising candidates for the next-generation green energy suppliers. The corn starch-derived carbon with in-situ multi-elements doping, initially carbonized by 6 mol/L H2SO4 and then calcined in nitrogen atmosphere, is employed to configure sulfur cathode for Lithium–Sulfur batteries in this study. As-received carbon with randomly distributed graphical domains serves as charge carriers diffusion channels during discharging/charging cycles, thus endowing the cathode considerable excellent performances. Specifically, the loading amount of sulfur in cathode is around 60.31 wt% and the effective utilization efficiency of active reagent sulfur in cathode is up to 60 %. On activating the cathode at 0.114 A g−1 at 0, 25 and 40 °C, the initial discharge capacities of the Lithium–Sulfur batteries with corn starch-derived carbon-based composite cathode (with ∼1.3 mg cm−2 sulfur) are 278.6, 1023.7 and 976.1 mAh∙g−1, respectively. Accordingly, more uniform, and thinner solid electrolyte interphase membrane formed under room temperature activation, leaving in the dramatically diminished Rsur value, contributes to the comparable cycling stability and rate performances of as-designed carbon-based sulfur cathode for Lithium–Sulfur Batteries.

Discharge characteristic analysis of lithium-sulfur batteries considering the discontinuous deposit and transport-limited effects

The modeling research plays a crucial role in grasping the reaction mechanisms and forecasting the performance of lithium-sulfur (Li–S) batteries. A transient Li–S battery model including continuity, transportation, and reaction kinetics by simultaneously considering the discontinuous deposit of discharge product Li2S and the transport limitation in the concentrated electrolyte, is developed to reveal the discharge phenomena. The effects of operating conditions and electrolyte and electrode properties on the discharge behaviors including voltage-capacity curve, energy density, profiles of solid product (ɛLi2S) and porosity (ɛ) at the cathode are quantitatively studied. It is found that low discharge rate is beneficial to the discharge capacity and utilization of cathode sulfur. Enhancing precipitate (S8) solubility Ksp, S8 and ionic diffusivity Di improves voltage plateau and specific energy to varying degrees; the promotion of voltage plateau will be inconspicuous as electrode conductivity σ is enlarged over 0.1 S/m. With the rise of ɛ from 0.5 to 0.9, the specific capacity and the specific energy are expanded by around 5 times. When lengthening Lca from 20 μm to 60 μm, the specific capacity ascends from 944.5 to 991.5 mAh/g-S, whereas the growth rate of specific capacity and specific energy decreases gradually; the practical total energy almost increases linearly with thickness, yielding a 218.75% enhancement. With a certain period of relaxation, the recovered cell capacity after the high discharge rate is higher than that after the low discharge rate. This work may guide in designing electrodes and electrolytes and provide performance regulation strategies for Li–S batteries.

Advance of Metal Compound Cathodes in Lithium Sulfur Batteries

With the rapid development of technology, people’s demand for energy is increasing day by day. Many energy devices electric vehicles and other technological products require high-energy lithium secondary batteries to operate. Higher electrochemical energy per unit volume and lower manufacturing cost than lithium batteries are the characteristic advantages of lithium sulfur (LiS) batteries. At the same time, it is environmentally friendly. The global reserves of elemental sulfur are also very abundant, and the cost is low. Therefore, LiS batteries have become one of the most promising secondary batteries in the future. However, LiS batteries also suffer from issues such as poor conductivity of the active substance sulfur, shuttle effect, volume expansion, and lithium dendrites. Research has found that the application of composite materials of metal compounds and sulfur in the cathode of LiS batteries can effectively limit the shuttle effect and poor conductivity of LiS batteries. It can effectively adsorb polysulfides generated in the reaction, optimize the electric performance of cathode sulfur, strengthen the rate performance and cycle stability of lithium ion battery, as well as reduce capacity degradation, significantly improving their electrochemical performance. This article reviews the research progress on the application of metal compounds, mainly metal oxides and metal sulfides, in the cathode of LiS batteries. It explores how this application can suppress shuttle effects and slow down capacity degradation and summarizes and looks forward to its development.

Palygorskite-Derived Ternary Fluoride with 2D Ion Transport Channels for Ampere Hour-Scale Li-S Pouch Cell with High Energy Density.

Although various excellent electrocatalysts/adsorbents have made notable progress as sulfur cathode hosts on the lithium-sulfur (Li-S) coin-cell level, high energy density (WG ) of the practical Li-S pouch cells is still limited by inefficient Li-ion transport in the thick sulfur cathode under low electrolyte/sulfur (E/S) and negative/positive (N/P) ratios, which aggravates the shuttle effect and sluggish redox kinetics. Here a new ternary fluoride MgAlF5 ·2H2 O with ultrafast ion conduction-strong polysulfides capture integration is developed. MgAlF5 ·2H2 O has an inverse Weberite-type crystal framework, in which the corner-sharing [AlF6 ]-[MgF4 (H2 O)2 ] octahedra units extend to form two-dimensional Li-ion transport channels along the [100] and [010] directions, respectively. Applied as the cathode sulfur host, the MgAlF5 ·2H2 O lithiated by LiTFSI (lithium salt in Li-S electrolyte) acts as a fast ionic conductor to ensure efficient Li-ion transport to accelerate the redox kinetics under high S loadings and low E/S and N/P. Meanwhile, the strong polar MgAlF5 ·2H2 O captures polysulfides by chemisorption to suppress the shuttle effect. Therefore, a 1.97Ah-level Li-S pouch cell achieves a high WG of 386Whkg-1 . This work develops a new-type ionic conductor, and provides unique insights and new hosts for designing practical Li-S pouch cells.

Carbon nanofibers implanted porous catalytic metal oxide design as efficient bifunctional electrode host material for lithium-sulfur battery

The shuttling effect of lithium polysulfides (LiPSs) and uncontrolled dendrite formation of metal lithium anode are the two critical obstacles hindering the commercial application of lithium-sulfur (Li-S) batteries. Herein, a bifunctional electrode host design consists of carbon nanofibers implanted ordered porous Co-decorated Al2O3 supported on carbon nanotube film (CNTF) is proposed to address these problems. As cathode sulfur host material, benefiting from the synergistic effect of porous Co-Al2O3 and the embedded CNFs, the CNFs/Co-Al2O3@CNTF exhibits excellent conductivity, efficient LiPSs confinement and catalytic conversion performance. It shows a high initial capacity of 1165 mAh g−1 at 0.2 C, and holds a capacity of 594 mAh g−1 even up to 3 C. When serves as anode, the CNFs/Co-Al2O3@CNTF electrode exhibits excellent Li+ diffusion performance and uniform lithium growth behavior, achieving a dendrite-free lithium electrode. The anode also shows good cycle stability during an ultra-long cycle time of 1000 h. A flexible pack cell assembled from CNFs/Co-Al2O3@CNTF electrodes delivers a specific capacity of 972 mAh g−1 with capacity retention rate of 86.4% at 0.1 C.

Application of ZIF-67/ZIF-8 derived Co3O4/ZnO heterojunction in lithium-sulfur battery separators

Lithium-sulfur batteries (LSBs) have attracted widespread attention because of their advantages such as high discharge capacity and high energy density. Although LSBs have good development potential, there are still many obstacles, such as poor conductivity, volume expansion etc., especially shuttle effect which seriously limit the application of LSBs. To restrain the shuttle effect, we proposed a novel Co3O4/ZnO dodecahedral heterojunction as a separator blocking layer which was derived form ZIF-67/ZIF-8 bimetallic MOF. Since the bimetallic oxide heterojunction contains more abundant oxygen vacancies, it has better adsorption and catalytic performances than monometallic oxides. Co3O4/ZnO coated on the PE separator can effectively block the lithium polysulfides (LiPSs) shuttle due to its good adsorption ability, furthermore, the catalytic effect will accelerate the reaction of LiPSs and improve the electrochemical performances. Consequently, the initial discharge specific capacity of the Co3O4/ZnO modified separator battery at 0.5 C rate reaches up to 875.5 mAh g−1 when the cathode sulfur areal density is 3 mg cm−2, and still keep 500.9 mAh g−1 after 400 long cycles. Even when the cathode sulfur areal density is 5 mg cm−2, it still shows good cycle stability.

Manipulating Redox Kinetics using p-n Heterojunction Biservice Matrix as both Cathode Sulfur Immobilizer and Anode Lithium Stabilizer for Practical Lithium-Sulfur Batteries.

As an attractive high-energy-density technology, the practical application of lithium-sulfur (Li-S) batteries is severely limited by the notorious dissolution and shuttle effect of lithium polysulfides (LiPS), resulting in sluggish reaction kinetics and uncontrollable dendritic Li growth. Herein, a p-n typed heterostructure consisting of n-type MoS2 nanoflowers embedded with p-type NiO nanoparticles is designed on carbon nanofibers (denoted as NiO-MoS2 @CNFs) as both cathode sulfur immobilizer and anode Li stabilizer for practical Li-S batteries. Such p-n typed heterostructure is proposed to establish the built-in electric field across the heterointerface for facilitated the positive charge to reach the surface of NiO-MoS2 , meanwhile inherits the excellent LiPS adsorption ability of p-type NiO nanoparticles and catalytic ability of n-type MoS2 . As the anode matrix, the implementation of NiO-MoS2 heterostructure can prevent the growth of Li dendrites by enhancing the lithiophilicity and reducing local current density. The obtained Li-S full battery exhibits an ultra-high areal capacity over 7.3 mAh cm-2 , far exceeding that of current commercial Li-ion batteries. Meanwhile, a stable cycling performance can be achieved under low electrolyte/sulfur ratio of 5.8µL mg-1 and negative/positive capacity ratio of 1. The corresponding pouch cell maintains high energy density of 305Wh kg-1 and stable cycling performance under various bending angles.

Graphene/Heterojunction Composite Prepared by Carbon Thermal Reduction as a Sulfur Host for Lithium-Sulfur Batteries.

An interlayer nanocomposite (CC@rGO) consisting of a graphene heterojunction with CoO and Co9S8 was prepared using a simple and low-cost hydrothermal calcination method, which was tested as a cathode sulfur carrier for lithium-sulfur batteries. The CC@rGO composite comprises a spherical heterostructure uniformly distributed between graphene sheet layers, preventing stacking the graphene sheet layer. After the introduction of cobalt heterojunction on a graphene substrate, the Co element content increases the reactive sites of the composite and improves its electrochemical properties to some extent. The composite exhibited good cycling performance with an initial discharge capacity of 847.51 mAh/g at 0.5 C and a capacity decay rate of 0.0448% after 500 cycles, which also kept 452.91 mAh/g at 1 C and in the rate test from 3 C back to 0.1 C maintained 993.27 mAh/g. This article provides insight into the design of cathode materials for lithium-sulfur batteries.

Applications and Challenges of Lithium-Sulfur Electrochemical Batteries

<p>This paper presents applications of lithium-sulfur (Li-S) energy storage batteries, while showing merits and demerits of several techniques to mitigate their electrochemical challenges. Unmanned aerial vehicles, electric cars, and grid-scale energy storage systems represent main applications of Li-S batteries due to their low cost, high specific capacity, and light weight. However, polysulfide shuttle effects, low conductivities, and low coulombic efficiencies signify key challenges of Li-S batteries, causing high volumetric changes, dendritic growths, and limited cycling performances. Solid-state electrolytes, interfacial interlayers, and electrocatalysts denote promising methods to mitigate such challenges. Moreover, nanomaterials have capability to improve kinetic reactions of Li-S batteries based on several properties of nanoparticles to immobilize sulfur in cathodes, stabilizing lithium in anodes while controlling volumetric growths. Li-S energy storage technologies are able to satisfy requirements of future markets for advanced rechargeable batteries with high-power densities and low costs, considering environmentally friendly systems based on renewable energy sources.</p>

Synergistic realization of Co/N co-doped hierarchical vanadium trioxide core–shell sphere for ultra-long cycle performance of Li–S batteries

Lithium–sulfur (Li–S) battery has been recognized as one of the most promising energy systems due to its high specific capacity and energy density. However, its instinct defects, such as shuttle effect of lithium polysulfide (LPS), low conductivity, and high volume expansion of cathode sulfur (S), seriously hinder its commercialization process. Herein, a hierarchical vanadium trioxide (V2O3) core–shell sphere, which is self-assembled from zero-dimensional (0D) nanoparticles and integrated with 2D nanosheets and co-doped cobalt (Co) and nitrogen (N), has been prepared. After the hierarchical V2O3 core–shell sphere being served as a separator modifier, a synergistic effect of physisorption, chemisorption, and catalytic conversion of LPS can be well realized, leading to an effective inhibition of the shuttle effect. Hence, exceptional initial discharging capacities of 1485.3 and 1322.2 mAh g−1 can be obtained at 0.1 and 1C, respectively, and after 1100 ultra-long cycles, the capacity loss rate can be restricted at 0.064% per cycle; furthermore, a discharging capacity of 973.9 mAh g−1 can also be obtained even at a high current of 3C, and the capacity loss rate is only 0.059% per cycle during 1000 ultra-long cycles, showing extraordinary ultra-long cycle performance and rate performance.

Kinetic Acceleration of Lithium Polysulfide Conversion via a Copper-Iridium Alloying Catalytic Strategy in Li-S Batteries.

To solve the shuttle effect of soluble lithium polysulfides (LiPSs), a porous N-doped carbon-supported copper-iridium alloy catalyst composite (CuIr/NC) has been synthesized and served as a modified cathode sulfur host for lithium-sulfur batteries (LSBs). The metal-organic framework-derived calcined carbon frameworks build efficient conductive channels for fast ion/electron transport. Furthermore, alloying noble metals Ir with thiophilic metal Cu provides abundant active sites to effectively capture LiPSs and accelerate the catalytic conversion process, originating from modulating the surface electronic structure of the metal Cu by introducing Ir atoms to affect the 3d-orbital distribution. All of the above are strongly supported by a range of characterization studies and density functional theory calculations. Benefiting from the above advantages, the LSBs generally show satisfactory cycling performance. Apart from exhibiting a terrific initial specific capacity of 1288 mA h g-1 at 0.2 C, they can also keep long-term cycling stability under a high current density up to 5 C together with a slow specific capacity decay ratio (0.033%) per cycle after 1000 cycles. In addition, it is worth mentioning that a high areal capacity (4.7 mA h cm-2) with a low E/S ratio (6.2 μL mg-1) could still be accomplished at higher sulfur loading (4.3 mg cm-2).

CeO2-C nanorods obtained by high-temperature carbonization of Ce-MOF as separator coating for Li-S battery

Lithium-sulfur batteries (LSBs) are of great interest to researchers due to their high theoretical specific capacity and high energy density. Unfortunately, because of sulfur's weak conductivity and the shuttle effect of polysulfides, the application prospects of LSBs are facing great challenges. To suppress the shuttle effect of polysulfides, nanorod-like CeO2 and CeO2-C using Ce-MOF as the precursor was successfully prepared and applied to the separator of LSBs. Coating CeO2 and CeO2-C obtained by calcination in different atmospheres on PE separators can effectively enhance the electrochemical properties of LSBs due to the excellent chemisorption and catalytic effect of CeO2 on lithium polysulfides. In particular, CeO2-C which is obtained by calcination of Ce-MOF in N2 atmosphere has abundant micro and meso porous structures, which can quickly adsorb polysulfide in the electrolyte and accelerate the redox kinetics at the same time. Moreover, the nano-rod structure of CeO2 and CeO2-C also improves the conductivity of the separator. After a series of electrochemical tests, it was discovered that the discharge capacity of the CeO2-C coated separator battery on the first cycle was 1240 mA h g−1 when the cathode sulfur loading was approximately 2.5 mg cm−2, and that the discharge capacity remained 520 mA h g−1after 500 loops at 0.5 C. Even when the sulfur loading reaches 5.5 mg cm−2, it also has a good cyclic stability, demonstrating its application potential.

Cover Feature: Effective Ways to Stabilize Polysulfide Ions for High‐Capacity Li−S Batteries Based on Organic Chalcogenide Catholytes (ChemElectroChem 18/2022)

The Cover Feature illustrates the important role of both catholyte formulated with phenyl-dichalcogenide and nature of cathode's sulfur as key parameters enhancing the performance of Li-S batteries with high energy density. More information can be found in the Research Article by G. Nikiforidis et al.

Modified separator engineering with 2D ultrathin Ni3B@rGO: Extraordinary electrochemical performance of the lithium-sulfur battery with enormous-sulfur-content cathode in low electrolyte/sulfur ratio

Compared to other batteries, a next-generation lithium-sulfur (Li-S) battery's specific capacity and energy density are relatively high. However, the actual electrochemical performance (particularly for the cell with a high cathode sulfur content and a lean electrolyte/sulfur ratio) falls well short of practical usage requirements. The ultrathin Ni 3 B@rGO-PP is designed in this study as a unique modified separator for Li-S cells. Because of its distinct electronic structure, the modified separator shows outstanding adsorption ability toward polysulfide through the boron element's active sites. Additionally, it has excellent electrocatalytic activity, significantly enhancing the performance of Li-S batteries. After the 100th cycle, the cell with 80 wt% sulfur content can retain 819 mA h g −1 under 0.2 C. Also, when the electrolyte/sulfur ratio is reduced to 15 µL mg −1 and 5 µL mg −1 , respectively, considerable capacity retention of 736.3 mA h g −1 and 615 mA h g −1 is achieved after the 100th cycle at 0.2 C. What's more, for the high sulfur loading (single-side up to 4.5 mg cm −2 ) cathode, the cell obtains a retention capacity of 578 mA h g −1 after the 200th cycle under 0.2 C. The surface engineering strategy with the Ni 3 B@rGO modified coating adopted in this work would open an efficient route to acquire the Li-S battery's outstanding electrochemical capability in the practical application situation. The boron element's active cites provide a unique electronic structure to the Ni 3 B@rGO coating layer, which effectively enhance the adsorption ability toward polysulfide, and further provide excellent electrocatalytic activity during the charging/discharging process, greatly improving the electrochemical performance of Li-S batteries. Thus, the Ni 3 B@rGO-PP exhibits long cycling stability even at a low E/S ratio, fast Li + transportation, and high ionic conductivity. • The Ni 3 B@rGO nanohybrid developed as a novel modified coating on the celgard separator in Li-S batteries. • The Ni3B@rGO-PP show outstanding adsorption ability to LiPSs through B active cites and enhances the cell conductivity. • The Ni 3 B@rGO-PP exhibits excellent anti-self-discharge, high ionic conductivity, and fast Li + transportation. • The Ni3B@rGO-PP presents promising electrochemical performances with a high-sulfur-content cathode (up to 83 wt%).