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Recently, Li-ion capacitor as a kind of novel energy storage device with high energy density and power density have caused wide concern. In this study, the porous carbon nanofiber/molybdenum disulfide nanoflake-flowerballs composite material is successfully prepared via hydrothermal method using the three-dimensional porous carbon nanofibers as a carrier. The molybdenum disulfide nanoflake-flowerballs are uniformly distributed and fill in three-dimensional porous carbon nanofibers skeleton, and the clear composite material with nanofiber morphology is formed. This material presents moderate specific surface area (81.67 m2 g−1) and good electrical conductivity (22.32 S cm−1) and is used as the anode in the Li-ion capacitor, and the big energy density at high power density (the energy density could reach 75.5 Wh kg−1 and 22.5 Wh kg−1 at power densities of 0.075 kW kg−1 at 30 kW kg−1, respectively) are achieved, which has broad application prospect in the energy storage field. • The three-dimensional PCNF loading MoS 2 nanoflake-flowerballs was constructed. • The MoS 2 nanoflake-flowerballs inner nanofibers provide the large reaction area. • The three-dimensional PCNF skeleton offers conductive path. • The 3D-PCNF/MoS 2 -NFFBs used as the anodes of LICs exhibit excellent properties. [ABSTRACT FROM AUTHOR]

Li-ion capacitor as a kind of new-style energy storage devices has attracted growing attention due to its high power and energy density. In this study, the stereoscopic honeycomb-like porous carbon nanofiber (PCNF) was used as a carrier of TiO 2 nanoparticles via simple immersion and calcination. The equally distributed anatase TiO 2 nanoparticles filling in the stereoscopic honeycomb-like PCNF skeleton provided large reaction sites, and the stereoscopic honeycomb-like PCNFs acting as support materials offered shorter electrical paths. The composite material presented unique fiber morphology, high specific surface area (268.32 m2g-1) and preferable electrical conductivity (1.31 S cm−1) which was used as an anode in Li-ion capacitor, and the large energy density versus power density (69.46 Wh kg−1 at 0.15 kW kg−1, 18.33 Wh kg−1 at 30 kW kg−1) and good cycle stability (retains 79.4% after 4000 cycles at 1 A g−1) were achieved, which had broad application prospect in the energy storage field. • A stereoscopic honeycomb-like PCNF loading TiO 2 nanoparticles material is designed. • The TiO 2 nanoparticles uniformly distribute and fill in stereoscopic carbon skeleton. • The stereoscopic honeycomb-like PCNF skeleton offers electrical conductivity to TiO 2. • The LIC with TiO 2 @PCNF anode exhibits good electrochemical properties. [ABSTRACT FROM AUTHOR]

Abstract 'Corn-on-the-cob' structured ZnS nanoparticles anchored on porous carbon nanofibers (ZnS/PCNFs) were rationally designed and prepared using preoxidized PVA/PTFE nanofibers as porous matrix precursors through subsequent solvothermal and carbonization. The obtained ZnS/PCNFs composite as anode material for lithium ion batteries exhibit a promising cycling performance with high reversible capacity of 718 mAh g−1 at 0.2 A g−1 after 150 cycles and excellent rate capability with discharge capacity of 438 mAh g−1 at 2 A g−1. The prominent battery performance of ZnS/PCNFs electrode might be ascribed to the distinct hybrid structure, where the uniformly arranged nanosized ZnS 'corns' endowed the hybrid with excellent lithium capacitive performance, and the rationally designed PCNFs 'cob' with large specific surface area not only improved the conductivity but also enhanced the diffusion of electrolyte and ion movement within the hybrid. Graphical abstract Unlabelled Image Highlights • Porous carbon nanofibers were introduced as conductive matrices to hybridize with ZnS. • ZnS nanoparticles were uniformly anchored on porous carbon nanofibers with a unique 'corn-on-the-cob' structure. • The composites exhibited exceptional electrochemical performance. [ABSTRACT FROM AUTHOR]

The PVA-based carbon nanofibers with honeycomb-like carbon porous structure were successfully prepared by electro-blown spinning (EBS), pretreatment and carbonation processes. PVA was used as the carbonized polymer while PTFE was used as the sacrificial polymer. The carbon nanofibers with various pore sizes and distribution were prepared by varying the amount of PTFE loading in the spinning solution and optimizing carbonized parameters. The honeycomb-like carbon nanofibers were investigated by scanning electron microscopy (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectrum and low temperature nitrogen adsorption. It was found that specific surface area and pore volume could reach 591.33 m 2 g −1 and 0.58 cm 3 /g, respectively, and large amount of micro-, meso- and macro-pores existed in this kind of porous carbon fiber when the PVA/PTFE was 1:15. This porous carbon nanofiber with special structure and high yield may realize the applications in the fields of adsorption, ion exchange, catalyst supports, etc., and the prepared method has a great industrialization potentiality. [ABSTRACT FROM AUTHOR]

Lithium-sulfur battery is one of the most prospective chemistries in secondary energy storage field due to its high energy density and theoretical capacity, but the rapid decay of capacity is still a huge challenge. Herein, we reported an ingenious design of nitrogen doped carbon nanofibers with honeycomb-like porous structure for the cathode of lithium-sulfur battery which can effectively suppress the “shuttle effect”. The special porous material with three dimensional (3D) interconnected pore structure is beneficial to enhance the adsorption of lithium polysulfides and accommodate the volume expansion of active materials. In addition, the doped nitrogen can not only improve the conductivity of cathode, but also form a strong interfacial interaction to trap lithium polysulfides. Therefore, the battery with the cathode exhibited a high reversible discharge capacity of 1093.9 mAh g −1 and good capacity retention of 76.0% after 300 cycles at 0.5C rate. After acidification, the cycling performance of the cathode could achieve upon 300 cycles with a very low decay rate of 0.027% at 0.5C. [ABSTRACT FROM AUTHOR]

The honeycomb-like hierarchical porous carbon nanofibers (PCNFs)-carbon nanotubes (CNTs)-sulfur(S) composite electrode is successfully desgined and prepared through ball-milling and heating method, in which the PCNFs are carbonized from fibers in the membrane composed of Polyvinyl Alcohol and Polytetrafluoroethylene by electro-blown spinning technology. The prepared PCNFs-CNTs-S composite are regarded as cathode for lithium-sulfur battery. The tailored porous structure and CNTs in the composite facilitate construction of a high electrical conductive pathway and store more S/polysulfides, and the dissoluble loss of intermediate S species in electrolyte can also be restrained because of acidized PVA-based porous carbon nanofibers. Meanwhile, the porous strcucture and CNTs can effectively alleviate volume changes in battery cycling process. Moreover, the presence of LiNO 3 in electrolyte helps the electrochemical oxidation of Li 2 S and LiNO 3 -derived surface film effectively suppresses the migration of soluble polysulfide to the Li anode surface. Therefore, the obtained PCNFs-CNTs-S cathode exhibits excellent performance in Li-S battery with a high initial discharge capacity as high as 1302.9 mAh g −1 , and super stable capacity retention with 809.1 mAh g −1 after 300 cycles at the current density of 837.5 mA g −1 (0.5 C). And the rate capability of PCNFs-CNTs-S electrode is much better than those of CNTs-S and PCNFs-S electrodes. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries have been considered as one of the most promising energy storage candidates due to their high energy density and low cost. However, the low electrical conductivity of elemental sulfur, notorious LiPS shuttle and sluggish redox kinetics bring about fast capacity fade and poor rate capabilities. To solve these problems, herein a modification strategy of functional separator is introduced by coating heterostructured MoP–MoS 2 and porous carbon nanofibers (PCNFs) on the surface of a Celgard separator. Moreover, for the first time, we detailly discuss the effect of the ratio of component (MoP:MoS 2) in the heterostructured MoP–MoS 2 materials on the electrochemical performance. The coating layer exhibits both satisfactory interception ability for LiPS shuttle and fast LiPS conversion ability due to abundant anchoring sites of MoP–MoS 2 heterojunction nanoflowers and shortened lithium ion channel of the prepared PCNFs. Benefiting from these advantages, the assembled Li–S battery with a MoP-50/PCNFs separator exhibits 1090.02 mAh g-1, and high discharge capacity of 884.67 mAh g-1 even after 300 cycles at 1 C. The initial discharge capacity of MoP-50/PCNFs separator at 2 C and 5 C are about 1050.4 and 728.22 mAh g-1, and retains about 698.4 mAh g-1 after 400 cycles and 431.28 mAh g-1 after 500 cycles. The novel work will provide a new strategy by which the modified separator with transition metal phosphides can be applied in the design of high-performance Li–S batteries and shows great potential for practical application. MoP-x/PCNFs modified Celgard separator in Lithium-sulfur battery. [Display omitted] • Preparing Flower-like heterostructured MoP–MoS 2. • Designing various heterostructured MoP–MoS 2 materials (MoP: MoS 2 = 100:0, 75:25, 50:50, 25:75, 0:100). • Porous carbon nanofiber with dual functions of lithium polysulfudes adsorption through one-step electrostatic blowing method. • Researching the catalytic kinetic mechanism of the "solid-liquid-solid" mutual conversion process for transition metal phosphide. • Exploring the cycle performance of Celgard separator modified with MoP–MoS 2 -50/PCNFs. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries have been considered as one of the most promising energy storage candidates due to their high energy density and low cost. However, the low electrical conductivity of elemental sulfur, notorious LiPS shuttle and sluggish redox kinetics bring about fast capacity fade and poor rate capabilities. To solve these problems, herein a modification strategy of functional separator is introduced by coating heterostructured MoP–MoS 2 and porous carbon nanofibers (PCNFs) on the surface of a Celgard separator. Moreover, for the first time, we detailly discuss the effect of the ratio of component (MoP:MoS 2) in the heterostructured MoP–MoS 2 materials on the electrochemical performance. The coating layer exhibits both satisfactory interception ability for LiPS shuttle and fast LiPS conversion ability due to abundant anchoring sites of MoP–MoS 2 heterojunction nanoflowers and shortened lithium ion channel of the prepared PCNFs. Benefiting from these advantages, the assembled Li–S battery with a MoP-50/PCNFs separator exhibits 1090.02 mAh g-1, and high discharge capacity of 884.67 mAh g-1 even after 300 cycles at 1 C. The initial discharge capacity of MoP-50/PCNFs separator at 2 C and 5 C are about 1050.4 and 728.22 mAh g-1, and retains about 698.4 mAh g-1 after 400 cycles and 431.28 mAh g-1 after 500 cycles. The novel work will provide a new strategy by which the modified separator with transition metal phosphides can be applied in the design of high-performance Li–S batteries and shows great potential for practical application. MoP-x/PCNFs modified Celgard separator in Lithium-sulfur battery. [Display omitted] • Preparing Flower-like heterostructured MoP–MoS 2. • Designing various heterostructured MoP–MoS 2 materials (MoP: MoS 2 = 100:0, 75:25, 50:50, 25:75, 0:100). • Porous carbon nanofiber with dual functions of lithium polysulfudes adsorption through one-step electrostatic blowing method. • Researching the catalytic kinetic mechanism of the "solid-liquid-solid" mutual conversion process for transition metal phosphide. • Exploring the cycle performance of Celgard separator modified with MoP–MoS 2 -50/PCNFs. [ABSTRACT FROM AUTHOR]

Lithium (Li) metal is deemed as a promising anode for next-generation high-energy-density battery. However, the rebellious dendrites growth leads to the low Coulombic efficiency and safety hazards, which has been a key challenge in the application of Li metal anode. Herein, the ZnF 2 /ZnS heterostructures and N-doped carbon decorated porous carbon nanofibers (ZnF 2 /ZnS/NC/PCNFs) are fabricated through the electro-blow spinning (EBS), metal-organic framework (MOF)-assisted method, and carbonization process. And its application performances as coating functional interlayer of lithium metal batteries (LMBs) to suppress the Li dendrites growth are systematically researched. The conductive interconnected skeleton of NC/PCNFs provides convenient electrons/ions transmission channels and reduces local current density. The lithiophilic ZnF 2 and ZnS nanoparticles can trigger similar alloying reaction with Li-ions to guide the uniform Li deposition. In particular, the inbuilt electric field triggered at the interface of ZnF 2 /ZnS heterostructures improves charge transfer and surface reaction kinetics. Combining with these merits, the Li|LiFePO 4 (Li|LFP) cells with ZnF 2 /ZnS/NC/PCNFs deliver an optimal initial discharge capacity of 143.2 mAh g−1 and capacity retention rate of 93.6% after 600 cycles at 1 C. Moreover, the Li|Li symmetric cells show lower overpotential than that without the interlayer. Extraordinarily, the lithium-sulfur (Li|S) cells with ZnF 2 /ZnS/NC/PCNFs also display excellent cycle stability due to the strong captured or adsorbed ability to dissolved lithium polysulfides. All these results reveal that the utilization of the ZnF 2 /ZnS/NC/PCNFs interlayer provides new insight for protecting the Li metal anode and improving the electrochemical properties and safety of LMBs. [Display omitted] • The ZnF 2 /ZnS/NC/PCNFs interlayer was successfully prepared. • The interlayer provided convenient ions/electrons transmission channel. • ZnF 2 /ZnS heterostructures could enhance the charge transfer kinetics. • The interlayer could inhibit the Li dendrites growth for LMBs and absorb lithium polysulfides for Li.|S batteries. [ABSTRACT FROM AUTHOR]

• A novel multifunctional interlayer is successfully prepared. • The prepared interlayer mainly contains N-doped porous carbon nanofibers and Mg-Al layered double hydroxides. • The interlayer can suppress the "shuttle effect" and accelerate the redox reaction kinetics. • The Li-S battery with the MALDH@NPCNFs interlayer shows stable long-term cycle performance. [Display omitted] Lithium-sulfur (Li-S) battery as a promising energy storage technology has attracted extensive concern. However, their practical performance is seriously limited by the dissolution and diffusion of long-chain polysulfides. In this study, a multifunctional cathodic interlayer was constructed, which composed by Mg-Al layered double hydroxides (MALDHs) modified N-doped honeycomb-like porous carbon nanofibers (NPCNFs). The NPCNFs in the prepared interlayer can combine the physical confinement of the porous structure and the chemical role of the nitrogen atoms to suppress the dissolved lithium polysulfide (LiPS). Furthermore, highly conductive interlayer contains NPCNFs can be regarded as a second current collector, and the hierarchical pores is beneficial to adapt the volume change during the redox process. More importantly, the obtained polar MALDHs not only can strongly interact with LiPS by chemical combination, but also enhance the redox kinetics by forming cooperative interface. As a result, the Li-S cells with the cathodic interlayers obtains a high initial discharge capacity of 1452 mAh g−1 at 0.2 C, superior rate capability up to 2 C rate with a capacity of 952 mAh g−1 and excellent long-term cycling stability by maintaining a low average capacity fading (0.065% per cycle) during 500 cycles at 1 C. Therefore, the interlayer contains MALDH@NPCNFs has extraordinary potential to be used in high-performance Li-S batteries. [ABSTRACT FROM AUTHOR]