Lithium-sulfur batteries (LSBs) are regarded as a new kind of energy storage device due to their remarkable theoretical energy density. However, some issues, such as the low conductivity and the large volume variation of sulfur, as well as the formation of polysulfides during cycling, are yet to be addressed before LSBs can become an actual reality. Here, presented is a comprehensive overview illustrating the techniques capable of mitigating these undesirable problems together with the electrochemical performances associated to the different proposed solutions. In particular, the analysis is organized by separately addressing cathode, anode, separator, and electrolyte. Furthermore, to better understand the chemistry and failure mechanisms of LSBs, important characterization techniques applied to energy storage systems are reviewed. Similarly, considerations on the theoretical approaches used in the energy storage field are provided, as they can become the key tool for the design of the next generation LSBs. Afterward, the state of the art of LSBs technology is presented from a geopolitical perspective by comparing the results achieved in this field by the main world actors, namely Asia, North America, and Europe. Finally, this review is concluded with the application status of LSBs technology, and its prospects are offered.nonrenewable sources depletion and environment pollution (global warming and air/water quality). In particular, the abundant use of fossil fuels (especially coal and oil) is origin of many medical problems all over the world resulting in a constant rising of health-care national systems expenses. In this regard, especially solar and wind based energy sources, have been demonstrated to represent a valid alternative to fossil fuels. However, their energy instability related to a nonconstant presence of sun/wind, determines an intermittent energy production which severely jeopardize a stable and reliable energy supply to the grid. In order to mitigate and possibly even to completely solve this issue, a feasible solution is to couple solar/wind energy generators with energy storage devices. The presence of these systems would indeed allow the release of the produced energy into the grid at the right time, therefore avoiding any instability or even grid failure. Among the available energy storage devices, secondary batteries represent surely a valid choice owing to the abundant research in this field and to the number of applications already exploiting batteries as the main energy source. In this regard, here we recall lead-acid, nickel-cadmium and His work mainly aims in modeling and experimentally validating complex systems at the micro/nanoscale with strong emphasis on the final device. In particular, his research themes focus on the integration of different physics (i.e., interdisciplinary) such as photonics, heat diffusion, electric charge/mass diffusion, and mechanicaldeformation toward the development of innovative devices for energy manipulation (harvesting and storage).nitrogen element coul...

Interconnected hollow carbon nanospheres (HCNSs) were prepared by pressure‐assisted reduction and graphitization of sucrose in autoclaves without template. The obtained HCNSs with a large surface area, very thin graphitic shells, and an interconnected structure exhibit excellent performances as the electrode material for lithium ion batteries.

Carbon nano-onions (CNOs) were prepared at 600 °C by a simple reaction between copper dichloride hydrate (CuCl 2 3 2H 2 O) and calcium carbide (CaC 2 ). The morphology and structure of the obtained products were investigated by field-emission scanning electron microscope, high-resolution transmission electron microscopy, X-ray diffraction, Raman spectrum, and nitrogen adsorption. Large quantities of CNOs consisting of quasi-spherically concentric graphitic shells with high purity and uniform size distribution (about 30 nm) were obtained. The crystal water in CuCl 2 3 2H 2 O plays an important role in the formation of CNOs. The CNOs as-obtained exhibit high capacity and excellent cycling performance as anode materials for lithium-ion batteries, which can deliver a reversible capacity of 391 mAh g À1 up to 60 cycles.

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The effect of coagulation bath condition on the structure and property of the nascent fibers and polyacrylonitrile fibers during wet-spinning is studied. The best coagulation condition to produce polyacrylonitrile fibers has been found by examination of EA, XRD, SEM, and so on. The results indicated that when the coagulation bath was DMSO/H 2 O system, the temperature was 608C, the concentration was 65%, the minus stretch ratio was À10%, fine crystallites and high degree of crystallization in the nascent fibers and polyacrylonitrile fibers could be achieved, and less solvents remained in the nascent fibers with circular cross section morphology.

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