Low Activation Materials Research Articles

Directly Coating a Multifunctional Interlayer on the Cathode via Electrospinning for Advanced Lithium-Sulfur Batteries.

The lithium-sulfur battery is considered as a prospective candidate for a high-energy-storage system because of its high theoretical specific capacity and energy. However, the dissolution and shutter of polysulfides lead to low active material utilization and fast capacity fading. Electrospinning technology is employed to directly coat an interlayer composed of polyacrylonitrile (PAN) and nitrogen-doped carbon black (NC) fibers on the cathode. Benefiting from electrospinning technology, the PAN-NC fibers possess good electrolyte infiltration for fast lithium-ion transport and great flexibility for adhering on the cathode. The NC particles provide good affinity for polysufides and great conductivity. Thus, the polysulfides can be trapped on the cathode and reutilized well. As a result, the PAN-NC-coated sulfur cathode (PAN-NC@cathode) exhibits the initial discharge capacity of 1279 mAh g-1 and maintains the reversible capacity of 1030 mAh g-1 with capacity fading of 0.05% per cycle at 200 mA g-1 after 100 cycles. Adopting electrospinning to directly form fibers on the cathode shows a promising application.

Design Approach for FESS-FNSF In-Vessel Components and Constraints Imposed On Radial/Vertical Build Definition

The Fusion Nuclear Science Facility (FNSF) is an essential element of the U.S. developmental roadmap to fusion energy. The facility displays the complex integration of tokamak components and subsystems in fusion environment while testing and developing fusion technologies for the U.S. demonstration (DEMO) plant. The integration of the neutronics, shielding, and activation assessments is a key element to the success of FNSF operation. This paper overviews the engineering aspects of the tokamak-based FNSF study and presents an integral scheme that considered the overall configuration, radiation limits, top-level design requirements (including maximizing the tritium breeding ratio), smart selection of low-activation materials for each component, radial build optimization and definition, environmental and safety constraints, and upper temperatures for the reuse of reduced activation ferritic martensitic and bainitic structures after severe loss of coolant accidents.

Dose assessment from chronic exposure to industrial NORM in iron ore processing

Radiological exposures due to naturally occurring radioactive material (NORM) can occur during a wide range of work-related activities in the mineral processing and chemical industries. However, evaluation of such exposures in industrial settings remains a difficult exercise owing inter alia to the large number of personnel, operations and plants affected; assumptions that often have to be made concerning the actual duration and frequency of exposures; the complex chemistry and radioactive disequilibria involved and typically, the paucity of historical data. In our study, the challenges associated with assessing chronic exposure to fugitive dust enriched in 210Pb and 210Po and the determination of the associated internal dose by inhalation and ingestion are described by reference to a case study undertaken at an iron ore sintering plant between June 2013 and July 2015. The applicability of default dose coefficients and biokinetic models provided by the International Commission for Radiological Protection was verified by combining air and dust monitoring with information on the characteristics of the aerosols and in-vitro solubility experiments. The disparity between particulate matter 100 microns or less in diameter (PM100), particulate matter 10 microns or less in diameter (PM10) and 210Pb/210Po activity concentrations observed over the different monitoring campaigns and sampling locations confirmed that use positional short-term monitoring surveys to extrapolate intake over a year was not appropriate and could lead to unrealistic intake and dose figures. Personal air sampling is more appropriate for estimating the dose in such situations, though it is not always practical and may collect insufficient quantities of material for radiochemical analysis; this is an important constraint when dealing with low specific activity materials.

3D Conductive Network with High Loading Li2s for High Performance Lithium-Sulfur Batteries

Nowadays, lithium-sulfur (Li-S) batteries have been considered as one of the most promising next-generation rechargeable batteries, owing to their high theoretical specific capacity of 1672 mAh g−1, high energy density of 2600 Wh kg−1, low-cost and abundant resources. However, the commercial application of Li-S batteries is still hindered by several problems, including insulativity of element sulfur, dissolution of polysulfides and large volume expansion. In addition, sulfur cathodes need be paired with metallic lithium, which tends to form dendrites on the anode surface during cycling resulting in safety problems. Therefore, fully lithiated state of sulfur-lithium sulfide (Li2S) is advantageous over sulfur, because it can paired with metal-free anodes (e.g. graphite, silicon and Sn) avoiding safety problems. In addition, Li2S shows a high theoretical specific capacity of 1166 mAh g−1 and a high melting point of 938°C. Moreover, when Li2S convers to S companying with volume shrinkage, which will not only creates enough space for volumetric expansion but also makes the structure more stable. However, similar to sulfur cathode, low conductivity of Li2S, low active material loading and polysulfide dissolution Li2S limit application of Li2S for high performance batteries. Consequently, it is important to introduce Li2S into three dimensional conductive matrix/host for high performance. Herein, we construct a 3D conductive network with high loading Li2S through a facile liquid solution-evaporation. The 3D conductive network not only possesses a hierarchical architecture with abundant macroporous channels and exhibits a high surface area, which provides enough reaction sites to load and stabilize high-loading Li2S, but also improves the electronic conductivity of Li2S and demonstrates pronounced electrochemical performance with enhanced cycle stability and a good capacity retention.

High Areal Capacity Si/LiCoO2 Batteries from Electrospun Composite Fiber Mats.

Freestanding nanofiber mat Li-ion battery anodes containing Si nanoparticles, carbon black, and poly(acrylic acid) (Si/C/PAA) are prepared using electrospinning. The mats are compacted to a high fiber volume fraction (≈0.85), and interfiber contacts are welded by exposing the mat to methanol vapor. A compacted+welded fiber mat anode containing 40 wt % Si exhibits high capacities of 1484 mA h g-1 (3500 mA h g-1Si ) at 0.1 C and 489 mA h g-1 at 1 C and good cycling stability (e.g., 73 % capacity retention over 50 cycles). Post-mortem analysis of the fiber mats shows that the overall electrode structure is preserved during cycling. Whereas many nanostructured Si anodes are hindered by their low active material loadings and densities, thick, densely packed Si/C/PAA fiber mat anodes reported here have high areal and volumetric capacities (e.g., 4.5 mA h cm-2 and 750 mA h cm-3 , respectively). A full cell containing an electrospun Si/C/PAA anode and electrospun LiCoO2 -based cathode has a high specific energy density of 270 Wh kg-1 . The excellent performance of the electrospun Si/C/PAA fiber mat anodes is attributed to the: i) PAA binder, which interacts with the SiOx surface of Si nanoparticles and ii) high material loading, high fiber volume fraction, and welded interfiber contacts of the electrospun mats.

Development of the ultra-low background HPGe spectrometer OBELIX at Modane underground laboratory

A new ultra low-background spectrometer based on a HPGe detector with a sensitive volume of 600 cm3 was developed to investigate rare nuclear processes, such as resonant neutrino-less double electron capture (0νEC/EC) and double beta decay processes (2ν2β−, 2νβ+EC, 2νEC/EC) to the excited states of daughter nuclei. The spectrometer was installed at the Modane underground laboratory (LSM, France, 4800 m w.e.). Sensitivity of the spectrometer and its background were tested. A new method for the efficiency calibration in measurements of low-active samples was developed. The spectrometer was used for the measurements of low active materials and samples. Results obtained in 395 h investigation of resonant 0νEC/EC decay of 106Cd to the 2718 keV and 2741 keV excited states of 106Pd with ∼23.2 g of enriched 106Cd and 2ν2β− decay of 100Mo sample with a mass of 2588 g to the 0+, 1130 keV and 2+, 539.5 keV excited states of 100Ru are presented.

Design of the shielding wall of a cyclotron room and the activation interpretation using the Monte Carlo simulation

Medical cyclotron is mainly a facility used for producing radiopharmaceutical products, which secondarily generate high energy radiation when producing a radiopharmaceutical product. In this study, the intention is that the reductions in spatial dose rate for the radiation generated when cyclotron is operated and the absorbed dose rate, according to the width of shielding wall, will be analyzed. The simulation planned targetry and protons of 16.5 MeV, 60μA through a Monte Carlo simulation, and as a result of the simulation, it has been found through an analysis that a concrete shielding wall of 200 cm is needed, according to the absorbed dose rate of the shielding wall thickness of cyclotron, and the concrete gives an external exposure level of 1 μSv/hr after 19 years of cyclotron operation as it is activated by the nuclear reaction of cyclotron. When taking into account the mechanical life span of cyclotron, it is deemed necessary to develop additional shielding and a low activation material.

Volatile zirconium compounds: Prospects for use in gas-phase isotope separation

Data on volatile zirconium(IV) complexes are considered from the viewpoint of search for compounds exhibiting the required thermal parameters for centrifugal separation of stable isotopes. The results of studies concerning thermodynamics of vaporization of volatile zirconium compounds with inorganic and organic ligands are summarized and analyzed. The influence of the electronic structure of the central atom and of the molecular and crystal structure on the volatility of zirconium compounds is discussed. Promising lines of searching for volatile zirconium compounds for the development of low-activation materials based on isotopically altered elements are outlined.

Characterization and electrochemical activities of nanostructured transition metal nitrides as cathode materials for lithium sulfur batteries

Abstract The Lithium Sulfur (Li–S) battery system is one of the most promising candidates for electric vehicle applications due to its higher energy density when compared to conventional lithium ion batteries. However, there are some challenges facing Li−S battery commercialization, such as: low active material utilization, high self-discharge rate, and high rate of capacity fade. In this work, a series of transition metal nitrides: Tungsten nitride (WN), Molybdenum Nitride (Mo2N), and Vanadium Nitride (VN) was investigated as cathode materials for lithium polysulfide conversion reactions. Capacities of 697, 569, and 264 mAh g−1 were observed for WN, Mo2N, VN, respectively, with 8 mg cm−2 loading, after 100 cycles at a 0.1 C rate. WN higher electrochemical performance may be attributed to a strong reversible reaction between nitrides and polysulfide, which retains the sulfur species on the electrode surface, and minimizes the active material and surface area loss. X-ray photoelectron spectroscopy (XPS) analysis was performed to gain a better understanding of the mechanism underlying each metal nitride redox reactions.

Foldable and High Sulfur Loading 3D Carbon Electrode for High-performance Li-S Battery Application.

Sulfur is a promising cathode material with a high theoretical capacity of 1672 mAh g−1, however, the practical energy density of Li-S battery is far away from such promising due to its low active material utilization and low sulfur loading. Moreover, the challenges of the low electrical conductivity of sulfur and the high solubility of polysulfide intermediates still hinder its practical application. Here, we report a kind of free-standing and foldable cathodes consisting of 3D activated carbon fiber matrix and sulfur cathode. The 3D activated carbon fiber matrix (ACFC) has continuous conductive framework and sufficient internal space to provide a long-distance and continuous high-speed electron pathway. It also gives a very larger internal space and tortuous cathode region to ACFC accommodate a highly sulfur loading and keeps polysulfide within the cathode. The unique structured 3D foldable sulfur cathode using a foldable ACFC as matrix delivers a reversible capacity of about 979 mAh g−1 at 0.2C, a capacity retention of 98% after 100 cycles, and 0.02% capacity attenuation per cycle. Even at an areal capacity of 6 mAh cm−2, which is 2 times higher than the values of Li-ion battery, it still maintains an excellent rate capability and cycling performance.

Nanoengineering Energy Conversion and Storage Devices via Atomic Layer Deposition

Nanostructured materials show a promising future in energy conversion and storage. However, different challenges shall be addressed to take the full advantages of nanomaterials, such as excess charge recombination sites yielded from large surface area and inefficient charge carrier separation because of poor material junctions in solar cells and solar water splitting cells, as well as high risk of surface side reactions and low active material density in batteries and supercapacitors. Considering its surface self‐limiting reaction mechanism, atomic layer deposition (ALD) enables the deposition of a thin film on high aspect ratio structures with a highly controllable manner (e.g., atomic accuracy and perfect conformity), which make it very suitable to overcome the key challenges associated with the size and dimension decrease of nanomaterials. In this review, the recent progress of the ALD application and processing in energy‐related devices is highlighted. Particular emphasis is placed on employing ALD for improving the device performance via synthesizing, modifying, or stabilizing their corresponding components. Finally, the challenges regarding the material synthesis and scalable manufacturing of the ALD technique are also discussed.

Monoclinic sulfur cathode utilizing carbon for high-performance lithium–sulfur batteries

Abstract Sulfur cathodes for lithium–sulfur batteries have been designed to be combined with conductive carbon because the insulating nature of sulfur causes low active material utilization and poor rate capability. This paper is the first to report that carbon can induce a phase transition in a sulfur cathode. The stable form of a sulfur crystal at ambient temperature is orthorhombic sulfur. We found that monoclinic sulfur becomes more stable than orthorhombic sulfur if carbon atoms penetrate into the sulfur at elevated temperatures and the carbon density exceeds a threshold of C 0.3 S 8 . The high stability of the carbon-containing monoclinic sulfur persists during lithiation and is attributed to locally formed linear SC 3 S chains with marked stability. This study provides a novel perspective on the role of carbon in the sulfur cathode and suggests control of the crystal phase of electrodes by composite elements as a new way of designing efficient electrode materials.

Rechargeable Batteries Using Molecular Ions As a Charge Carrier

Is it possible to exceed the lithium redox potential in electrochemical systems? One may think the answer to be “No” because among all the elements the redox potential of the elemental lithium is the lowest, which leads to the high voltage characteristics of the widely used lithium ion batteries. However, the answer should turn “Yes” in principle when we use a molecule-based ion which is not reduced even at the lithium potential. Here we examined a model battery system using a few molecular ion charge carriers such as PF6 – and Me4N+with organic active materials. Although the potential of the negative-electrode is not yet lower than that of lithium at present, this study reveals that molecular ions can work as a “rocking chair” type charge carrier in a battery [1]. There are so far a few studies [2-5] describing the use of a molecular ion as the charge carrier; however, its stoichiometery has rarely been analyzed. To construct a “rocking chair” type molecular ion battery using, for instance, an anion charge carrier, we used a PF6 –-based electrolyte solution with two redox polymers (poly(N-vinylcarbazole): PVK, poly(1,1'-pentyl-4,4'-bipyridinium dihexafluorophosphate): PBPy) (Fig. 1a) as active materials. As for the molecular ion battery which uses a cation charge carrier, we chose a Me4N+-based electrolyte with some low molecular weight quinone type organic active materials. As shown in Fig.1b, the prepared sealed full cell using a PF6 –-based electrolyte system exhibited the potential difference of about 1.8 V with about 100 mAh/g(PVK). The cell exhibited a fairly good cycle stability; the cell maintained about 65% of the initial capacity after 100 cycles. The cell using the Me4N+-based electrolyte system also showed a repeatable charge/discharge behavior. The concept of these molecular ion batteries was proved by energy dispersive X-ray (EDX) measurement: we evaluated the change in stoichiometry of PF6 – in the electrode of the former cell ex situ by EDX and found that the charge carrier in this system is PF6 – and the prepared system is certainly a PF6 –-based “rocking chair type” battery. When succeeded in further developing the molecular ion battery, the benefits we would gain are: Breaking through the Li potential limitation, High ion conductivity in the electrolyte solution, Free from the dendrite risk, Minor metal free, and so on. To enjoy these benefits, the development in the active materials of both the positive- and negative-electrodes is indispensable. Searching for a negative electrode active material with a low redox potential is especially significant, which, we believe, will pave the way for the progress of this new battery system.

A Series of Unique Carbon Materials for Lithium-Sulphur Batteries

Lithium-sulphur (Li-S) cells are attractive electrochemical energy storage systems because of the high theoretical capacity of 1675 mAh g-1of sulphur. But low active material utilization, poor cycle life and low rate performance hinder their practicality, which arising from the highly insulating nature of sulphur, the high solubility/diffusivity of lithium polysulphides in the organic electrolyte and volumetric expansion of sulphur during lithiation. Carbon materials with high specific surface area and the porous structure are beneficial for uniform loading and distribution of sulphur in the structure to improve the reaction of sulphur in the cathode. It is important to maintain the electrical conductivity network of carbon providing envelope for lithium sulphide reduction and oxidation within a liquid solvent electrolyte without loss of fluidity, while minimising shuttling away of sulphur and avoiding or controlling the deposition of insoluble sulphides which can block the conducting paths. In addition, porous space could accommodate the volume variation of sulphur. Therefore, sulphur-carbon composites, using porous carbon have become a key research topic in Li-S batteries. Herein, the design and preparation of a series of unique carbon materials, based on metal organic framework (MOF)-derived hierarchical porous carbon, graphene-wrapped microporous carbon composite, few-layer graphene foam and carbon nanotube forest, have been demonstrated for sulphur loading to fabricate cathode structures for Li-S batteries. The improved electrochemical performance provides novel approaches to designing and fabricating long cycle life cathodes in Li-S cells. Reference 1. Nano Energy, 2015, 12, 538-546. 2. Nanoscale, 2014, 6, 5746-5753. 3. APL Materials, 2014, 2(12), 124109. 4. Chemical Communications , 2013, 49, 2192-2194.

Simultaneous optimization of surface chemistry and pore morphology of 3D graphene-sulfur cathode via multi-ion modulation

Lithium/sulfur (Li/S) battery is a promising next-generation energy storage system owing to its high theoretical energy density. However, for practical use there remains some key problems to be solved, such as low active material utilization and rapid capacity fading, especially at high areal sulfur loadings. Here, we report a facile one-pot method to prepare porous three-dimensional nitrogen, sulfur-codoped graphene through hydrothermal reduction of graphene oxide with multi-ion mixture modulation. We show solid evidence that the results of multi-ion mixture modulation can not only improve the surface affinity of the nanocarbons to polysulfides, but also alter their assembling manner and render the resultant 3D network a more favorable pore morphology for accommodating and confining sulfur. It also had an excellent rate performance and cycling stability, showing an initial capacity of 1304 mA h g−1 at 0.05C, 613 mA h g−1 at 5C and maintaining a reversible capacity of 462 mA h g−1 after 1500 cycles at 2C with capacity fading as low as 0.028% per cycle. Moreover, a high areal capacity of 5.1 mA h cm−2 at 0.2C is achieved at an areal sulfur loading of 6.3 mg cm−2, which are the best values reported so far for dual-doped sulfur cathodes.

Nanostructured titanium nitride as a novel cathode for high performance lithium/dissolved polysulfide batteries

Lithium–sulfur (LiS) batteries could potentially revolutionize the rechargeable battery market due to their high energy density and low cost. However, low active material utilization, electrode volumetric expansion and a high rate of capacity fade due to the dissolution of lithium polysulfide intermediates in the liquid electrolyte are the main challenges facing further LiS battery development. Here, we enhanced LiS batteries active material utilization and decreased the volumetric expansion by using the lithium/dissolved polysulfide configuration. Moreover, a novel class of cathode materials, Titanium Nitride (TiN), was developed for polysulfide conversion reactions. The surface chemical environment of the TiN has been investigated by X-ray photoelectron spectroscopy (XPS) analysis. The existence of STiN bonding at the cathode electrode surface was observed, which indicates the strong interactions between TiN and polysulfides. Therefore, the TiN electrode retains the sulfur species on the cathode surface, minimizing the active material and surface area loss and consequently, improves the capacity retention. The resultant cells demonstrated a high initial capacity of 1524 mAh g−1 and a good capacity retention for 100 cycles at a C/10 current rate.

Materials research for fusion

Fusion materials research started in the early 1970s following the observation of the degradation of irradiated materials used in the first commercial fission reactors. The technological challenges of fusion energy are intimately linked with the availability of suitable materials capable of reliably withstanding the extremely severe operational conditions of fusion reactors. Although fission and fusion materials exhibit common features, fusion materials research is broader. The harder mono-energetic spectrum associated with the deuterium–tritium fusion neutrons (14.1 MeV compared to <2 MeV on average for fission neutrons) releases significant amounts of hydrogen and helium as transmutation products that might lead to a (at present undetermined) degradation of structural materials after a few years of operation. Overcoming the historical lack of a fusion-relevant neutron source for materials testing is an essential pending step in fusion roadmaps. Structural materials development, together with research on functional materials capable of sustaining unprecedented power densities during plasma operation in a fusion reactor, have been the subject of decades of worldwide research efforts underpinning the present maturity of the fusion materials research programme. For achieving proper safety and efficiency of future fusion power plants, low-activation materials able to withstand the extreme fusion conditions are needed. Here, the irradiation physics at play and fusion materials research is reviewed.

(Invited) Catholyte-Based High Capacity Li-Sulfur Batteries

There is currently a considerable interest in the development of high capacity energy storage technologies. It is driven by the need in transport applications, such as electric vehicles (EV) where a capacity to go more than 500 km on one charge would be a desirable goal, as well as by renewable energy applications based on intermittent sources. The state-of-the-art for commercial rechargeable energy storage systems is the lithium ion battery (LIB) which has revolutionized the market for portable electronics. However, neither their capacity nor their price is currently matching the needs from the automotive or the renewable energy sectors. In addition, there is a need to improve the sustainability of the battery when considering mass implementation of large-scale energy storage systems. Li-Sulfur (LiS) technology has great potential for large-scale energy storage applications due to the very high theoretical specific capacity (1675 mAh g-1) and high energy density (2500 Wh kg-1) [1]. In addition the technology has potential for being a sustainable solution due to the abundance, low price and low toxicity of sulfur. However, a much lower practical capacity, limited cyclability, and low rate capability prevent commercialization of the technology. The origin of many of the problems can be traced to the intrinsic electrochemical process of the Li-Sulfur cell. During discharge sulfur is converted to Li2S through a series of steps involving the creation of lithium polysulfides (Li2Sx, 2<x≤8). A major issue is that these polysulfides have a relatively large solubility in standard electrolytes. In addition, the dissolved polysulfides cause degradation of the anode through shuttle reactions when they migrate through the electrolyte, forming insoluble layers on the anode surface. This leads to active material loss during the discharge-charge process gradually reducing the capacity and decreased Coulombic efficiency of the cell [7-10]. In addition, conducting material has to be added to sulfur (more than 30 wt%) when forming the cathode since sulfur has low electronic conductivity Consequently, the amount of active material in the cathode is further decreased, as is consequently the practical energy density of the cell. The problems in the Li-Sulfur battery can be addressed by new materials concepts for both the electrolyte and the cathode. For the development of the electrolyte promising approaches include moving away from organic solvents, improving both performance and safety, and the use of polymer gel or solid polymer electrolytes or ceramic electrolytes [2]. It has also been shown that by deliberately adding polysulfides to the electrolyte a more stable cycling, high capacity and good utilization of active material can be obtained [3]. To mitigate the polysulfide dissolution, and improve the conductivity of the cathode at the same time, nanostructured porous-carbon/sulfur composites have been applied [1]. Even though these approaches have proven rather successful in preventing polysulfide dissolution the practical energy density of these cells remain limited due to rather low active material (sulfur) loading. In this contribution we present different approaches towards Li-Sulfur cells with improved stability, safety, and high energy density. These include both new electrolyte and cathode solutions [2]. In particular we will discuss the application of the catholyte concept, where the active material is dissolved in the electrolyte. We show that by using a nanostructured porous-carbon cathode we can obtain a very high practical energy density, high sulfur utilization, and stable cycling. We also discuss the role of the presence of polysulfides in the electrolyte for the stabilization of the Li-metal anode in this cell [4].

A Novel Strategy for Configuration of an Integrated Flexible Sulfur Cathode for High-Performance Lithium-Sulfur Batteries

Lithium-sulfur batteries are regarded as promising candidates for energy storage devices due to their high theoretical energy density. The practical application is hindered, however, by low active material utilization and unsatisfactory capacity retention caused by the diffusion of polysulfides. Herein, we present a novel strategy for the configuration of the sulfur cathode, which is composed of an integrated carbon/sulfur/carbon sandwich structure on polypropylene separator (CSC@separator) that is produced via the simple doctor blade technique. The integrated electrode exhibits excellent flexibility and high mechanical strength. The upper and bottom carbon layers of the sandwich-structured electrode not only work as double current collectors which effectively improve the conductivity of the electrode, but also serve as good barriers, suppressing the diffusion of the polysulfide and buffering the volume expansion of the active materials during cycling. The CSC@separator cathode delivers high reversible capacity of 730 mAh g-1 after 500 cycles with a small capacity decay of 0.058% per cycle, and also demonstrates low self-discharge behaviour.

A novel separator coated by carbon for achieving exceptional high performance lithium-sulfur batteries

Lithium-sulfur batteries have received intense attention because of their high theoretical capacity, low cost and environmental friendliness. However, low active material utilization and poor cycle life limit their practical applications. Here, we report a strategy to obtain high capacity with long cycle life and rapid charge rate by introducing a carbon coating on the separator. Excellent cycling performance with a high capacity 956mAhg−1 after 200 cycles and outstanding high-rate response up to 4C are achieved, which are among the best reports so far. High electrochemical performance can be obtained even at a high sulfur loading of 3.37mgcm−2. Such improved results could be ascribed to the conductive carbon coating, which not only reduces the cell resistance but blocks the diffusion of soluble polysulfides avoiding shuttle effect during cycling. This study demonstrates a feasible, low cost and scalable approach to address the long-term cycling challenge for lithium-sulfur batteries.