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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...

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MXenes, as a new family of 2D materials, can be used as film electrodes in energy storage devices because of their hydrophilic surface, metallic conductivity, and rich surface chemistries. However, the poor ion transport of MXene film electrodes causes a great loss of surface reactivity, which significantly inhibits the full exploitation of the potential of MXene-based materials. To solve this issue, we report a facile electrolyte-induced self-assembly method to construct a 3D porous structure in the MXene-rGO hybrid film, which effectively facilitates rapid diffusion and transport of electrolyte ions in the film electrode while still maintaining high electrical conductivity. When the hybrid film is employed as electrode materials for lithium-ion batteries, it exhibits high specific capacity of 335.5 mA h g at 0.05 A g and good rate capability of 30% capacitance retention at 4 A g. Additionally, the film electrode exhibits excellent cycling stability without capacity decay after 1000 cycles under high rates (1 A g) owing to its stable structure. Furthermore, the electrochemical analysis also demonstrates that the novel 3D porous microstructure plays an important role in the fast reaction kinetics and high capacity of the MXene-rGO hybrid film electrode. This work may provide a new strategy to solve the issues related to poor ionic transport in MXene-based film electrodes.

A simple and scalable method is developed to synthesize TiO(2)/graphene nanostructured composites as high-performance anode materials for Li-ion batteries using hydroxyl titanium oxalate (HTO) as the intermediate for TiO(2). With assistance of a surfactant, amorphous HTO can condense as a flower-like nanostructure on graphene oxide (GO) sheets. By calcination, the HTO/GO nanocomposite can be converted to TiO(2)/graphene nanocomposite with well preserved flower-like nanostructure. In the composite, TiO(2) nanoparticles with an ultrasmall size of several nanometers construct the porous flower-like nanostructure which strongly attached onto conductive graphene nanosheets. The TiO(2)/graphene nanocomposite is able to deliver a capacity of 230 mA h g(-1) at 0.1 C (corresponding to a current density of 17 mA g(-1)), and demonstrates superior high-rate charge-discharge capability and cycling stability at charge/discharge rates up to 50 C in a half cell configuration. Full cell measurement using the TiO(2)/graphene as the anode material and spinel LiMnO(2) as the cathode material exhibit good high-rate performance and cycling stability, indicating that the TiO(2)/graphene nanocomposite has a practical application potential in advanced Li-ion batteries.

To develop high‐power and high‐energy batteries with a long life remains a great challenge, even combining the benefits of metal (fast kinetics and high capacity) and carbon materials (robust structure). Among them, Al‐ion batteries based on aluminum anode and graphite carbon cathode have gained lots of interests as one of the most promising technologies. Here, it is demonstrated that the size of graphitic material in ab plane and c direction plays an important role in anion intercalation chemistry. Sharply decreasing the size of vertical dimension (c direction) strongly facilitates the kinetics and charge transfer of anions (de)intercalation. On the other hand, increasing the size of horizontal dimension (ab plane) contributes to improving the flexibility of graphitic materials, which results in raising the cycling stability. Meanwhile, chloroaluminate anions are reversibly intercalated into the interlayer of graphite materials, leading to the staging behaviors. In the end, an ultrafast Al‐ion battery with exceptional long life is achieved based on large‐sized few‐layer graphene as a cathode and aluminum metal as an anode.

High yield production of graphene oxide and graphene sheets with an ultralarge size (up to approximately 200 microm) was realized using a modified solution-phase method.