Claudio Capiglia

Direct Synthesis of Carbon-Doped TiO2–Bronze Nanowires as Anode Materials for High Performance Lithium-Ion Batteries

Carbon-doped TiO2-bronze nanowires were synthesized via a facile doping mechanism and were exploited as active material for Li-ion batteries. We demonstrate that both the wire geometry and the presence of carbon doping contribute to the high electrochemical performance of these materials. Direct carbon doping for example reduces the Li-ion diffusion length and improves the electrical conductivity of the wires, as demonstrated by cycling experiments, which evidenced remarkably higher capacities and superior rate capability over the undoped nanowires. The as-prepared carbon-doped nanowires, evaluated in lithium half-cells, exhibited lithium storage capacity of ∼306 mA h g(-1) (91% of the theoretical capacity) at the current rate of 0.1C as well as excellent discharge capacity of ∼160 mAh g(-1) even at the current rate of 10 C after 1000 charge/discharge cycles.

Next-generation textiles: from embedded supercapacitors to lithium ion batteries

This review summarizes the cutting edge advances in the field of textile-based energy storage devices with particular emphasis on the nature and preparation of electrode materials for both supercapacitors and lithium ion batteries. Indeed, due to the overwhelming increase of the worldwide demand for high-tech products, energy storage has become one of the most up-to-date debating topics. In this regard, and considering also the well-known environmental issues often related to the fabrication of new energy products, it is important for the scientific community to develop new electrochemical energy storage systems based on eco-efficient synthetic processes and capable of serving the needs of the next generation of electronics. To this end, textile-based energy storage devices are emerging as a viable alternative to their conventional rigid counterparts. These devices have to be flexible, lightweight and should be compatible with futuristic miniaturized electronic gadgets. We have discussed how supercapacitors and Li-ion batteries are combined with textiles to realize flexible and wearable storage devices. The most important parameters, both from the electrochemical and textile points of view, have been taken into account in order to provide, as much as possible, a standard reference for comparing different kinds of textile-based energy storage devices. These parameters include electrode fibers configuration, fiber diameter, tensile strength, capacitance, charge/discharge capacity, Coulombic efficiency and capacity retention. Furthermore, in this review textile electrodes have been classified into two categories, according to the fabrication strategies: bottom-up and top-down fabrication processes. To conclude, the main aim of this review is to provide an organic outline of the recent research progress and perspectives on textile-based energy storage devices.

Nitrogen-Doped Single-Walled Carbon Nanohorns as a Cost-Effective Carbon Host toward High-Performance Lithium–Sulfur Batteries

Nitrogen-doped single-walled carbon nanohorns (N-SWCNHs) are porous carbon material characterized by unique horn-shape structures with high surface areas and good conductivity. Moreover, they can be mass-produced (tons/year) using a novel proprietary process technology making them an attractive material for various industrial applications. One of the applications is the encapsulation of sulfur, which turns them as promising conductive host materials for lithium-sulfur batteries. Therefore, we explore for the first time the electrochemical performance of industrially produced N-SWCNHs as a sulfur-encapsulating conductive material. Fabrication of lithium-sulfur cells based on N-SWCNHs with sulfur composite could achieve a remarkable initial gravimetric capacity of 1650 mA h g-1, namely equal to 98.5% of the theoretical capacity (1675 mA h g-1), with an exceptional sulfur content as high as 80% in weight. Using cyclic chronopotentiometry and impedance spectroscopy, we also explored the dissolution mechanism of polysulfides inside the electrolyte.

Facile synthesis of Ge–MWCNT nanocomposite electrodes for high capacity lithium ion batteries

Germanium (Ge) nanocrystals combined with multiwalled carbon nanotube (Ge–MWCNT) composites were synthesized via a solvothermal approach and characterized through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and scanning and transmission electron microscopy (SEM and TEM). The electrochemical behaviour during lithium insertion and de-insertion was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge–discharge measurements. The as prepared Ge–MWCNT nanocomposite exhibits improved cycling performance with higher capacity retention than pristine Ge. The Ge–MWCNTs exhibit a discharge capacity of ∼1160 mA h g−1 after 60 cycles at a current rate of 0.1C. Furthermore, they showed an excellent rate performance at a current rate of 5C (where 1C is 1600 mA g−1) by delivering a specific capacity of ∼406 mA h g−1 over 400 charge–discharge cycles.