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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]

Graphical abstract Highlights • Carbon nanofibers with hierarchical pore structure (HPCNFs) were applied as conductive matrices to hybridize with red P. • Red P were embedded in HPCHFs with a homogeneous and sufficient distribution. • P-HPCNFs anodes exhibited promising electrochemical performance. Abstract Red phosphorus (P) with high theoretical capacity and cost-efficiency shows tremendous potential as high-performance anode material. Here, we designed hierarchical porous carbon nanofibers (HPCNFs) by electro-blown spinning of polyvinyl alcohol/polytetrafluoroethylene (PVA/PTFE) with following carbonization and then encapsulated P into this HPCNFs via vaporization-condensation. The P-HPCNFs anodes presented a promising cyclability with reversible capacity of 883 mAh g−1 after 100 cycles and rate performance of 606 mAh g−1 at 1 A g−1. The improvement of electrochemical performance for P-HPCNFs could result from unique nanostructure, in which HPCNFs ensured not only the high conductivity of electrons but also the stable structural integrity. Additionally, the designed hierarchical pore structure with sufficient surface area well accommodated the volume change and highly facilitated the access of electrolyte to active P. [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 different fabrication techniques of nanofiber materials are summarized. • The functional action mechanisms of nanofibers for inhibiting Li dendrites are reviewed. • Various protection strategies of nanofiber materials to suppress the Li dendrites growth are summarized. • The challenges and prospects of nanofiber materials for Li anode are discussed. Lithium metal batteries (LMBs) are regarded as one of the most promising candidates for next-generation energy storage systems. However, the uncontrolled dendritic lithium (Li) growth lead to low Coulombic efficiency and security issue, thus limiting the commercial applications of LMBs. Owing to the unique nanostructure characteristics, nanofiber materials offer innovative strategies and opportunities to resolve the tricky challenge. A comprehensive review of the fundamental researches and technological developments of various nanofiber materials for LMBs was presented in this paper. The fabrication techniques of nanofibers and several functional action mechanisms for inhibiting dendritic Li were outlined. Then the different protection technologies of nanofiber materials for LMBs to suppress the Li dendrites growth were summarized, which included modifying separators, introducing functional interlayers and constructing novel composite anodes and current collectors. Meanwhile, the electrochemical performances using different strategies of the overall LMBs were discussed. Finally, the current challenges and prospects of nanofiber materials for Li anode were discussed. These discussions and proposed strategies will enlighten thoughts and offer ways to the practical application of LMBs with excellent electrochemical performances in the future. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur (Li‐S) batteries are in the spotlight because their outstanding theoretical specific energy is much higher than those of the commercial lithium ion (Li‐ion) batteries. Li‐S batteries are tough competitors for future‐developing energy storage in the fields of portable electronics and electric vehicles. However, the severe "shuttle effect" of the polysulfides and the serious damage of lithium dendrites are main factors blocking commercial production of Li‐S batteries. Owing to their superior nanostructure, electrospun nanofiber materials commonly show some unique characteristics that can simultaneously resolve these issues. So far, various novel cathodes, separators, and interlayers of electrospun nanofiber materials which are applied to resolve these challenges are researched. This review presents the fundamental research and technological development of multifarious electrospun nanofiber materials for Li‐S cells, including their processing methods, structures, morphology engineering, and electrochemical performance. Not only does the review article contain a summary of electrospun nanofiber materials in Li‐S batteries but also a proposal for designing electrospun nanofiber materials for Li‐S cells. These systematic discussions and proposed directions can enlighten thoughts and offer ways in the reasonable design of electrospun nanofiber materials for excellent Li‐S batteries in the near future. [ABSTRACT FROM AUTHOR]

Lithium-sulfur battery is considered as one of high performance batteries of the new generation owing to its extremely high theoretical capacity, energy density, good environmental protection and low cost. These features make it of great significance to serve as the next-generation battery especially in electric vehicles and portable devices. However, the practical application of lithium-sulfur battery is still hindered due to some obstacles including the low electrical and ionic conductivity of elemental sulfur, the discharge product Li 2 S and the “shuttle effect” caused by the dissolved polysulfide species. In this review, the current trends, fundamental studies and developments for lithium-sulfur battery separators including some modified functional and novel battery separators with the customized structure designs are presented and reviewed. The effects of different selections and the resulting properties of the separators affecting the overall lithium-sulfur battery performances are discussed as well. The current research directions and challenges associated with the use of battery separator and the future perspectives for this class of the battery separator are concluded as well. [ABSTRACT FROM AUTHOR]