Composites are prepared by simple mixture of laser pyrolysed silicon nanoparticles and petroleum pitch, a low cost carbon source. Helped by a homogeneous dispersion of Si nanoparticles into the pitch matrix high stability over cycling is observed.

Mesoporous Starbon® was shown to surpass conventional carbon additives in Li-ion batteries negative electrodes.

Mesoporous TiO -carbon nanocomposites were synthesized using an original non-hydrolytic sol-gel (NHSG) route, based on the reaction of simple ethers (diisopropyl ether or tetrahydrofuran) with titanium tetrachloride. In this atom-economic, solvent-free process, the ether acts not only as an oxygen donor but also as the sole carbon source. Increasing the reaction temperature to 180 °C leads to the decomposition of the alkyl chloride by-product and to the formation of hydrocarbon polymers, which are converted to carbon by pyrolysis under argon. The carbon-TiO nanocomposites and their TiO counterparts (obtained by calcination) were characterized by nitrogen physisorption, XRD, solid state C NMR and Raman spectroscopies, SEM, and TEM. The nanocomposites are mesoporous with surface areas of up to 75 m g and pore sizes around 10 nm. They are composed of aggregated anatase nanocrystals coated by an amorphous carbon film. Playing on the nature of the ether and on the reaction temperature allows control over the carbon content in the nanocomposites. The nature of the ether also influences the size of the TiO crystallites and the morphology of the nanocomposite. To further characterize the carbon coating, the behavior of the carbon-TiO nanocomposites and bare TiO samples toward lithium insertion-deinsertion was investigated in half-cells. This simple NHSG approach should provide a general method for the synthesis of a wide range of carbon-metal oxide nanocomposites.

Hard carbons are promising anode materials for Na-ion batteries that can be produced using a wide variety of synthetic or natural precursors. This work focuses on the development of hard carbons from natural polyphenols derived from different vegetal extracts. Herein, five natural tannin-based polyphenols (catechu, chestnut, myrobalan, and two mimosa extracts) were used to synthesize hard carbons through a single pyrolysis process at 1500 °C. The precursors lead to a high carbon yield (35–44%) and the obtained hard carbons have disordered structures with a large interlayer spacing (d 002 between 3.55 and 3.67 Å) and acertain amount of inorganic compounds (< 6 wt %). N2 and CO2 physisorption assays revealed the presence of a low volume of meso-, micro-, and ultramicropores and very low specific surface areas (SSAs) (N2-SSA < 7 m2·g–1 and CO2-SSA < 24 m2·g–1). The electrochemical performance showed a high initial Coulombic efficiency (iCE > 84%), which reached 100% after a few cycles, as well as good cycling stability. Myrobalan- and mimosa-based hard carbons exhibited reversible capacities of approximately 304 mAh·g–1 when cycled at C/10 (C = 372 mA·g–1), whereas catechu- and chestnut-derived hard carbons exhibited reversible capacities of 280 mAh·g–1, due to the presence of impurities, localized graphitic domains, and slightly lower d 002 values. In addition, the electrochemical behavior of myrobalan- and mimosa-based hard carbons is stable at higher current densities (C), while the capacity decreases for the other materials. The best performance was achieved for materials with low impurity levels, more disordered structures, and low specific surface areas (i.e., myrobalan-derived hard carbon).

Mesoporous nanocrystalline TiO 2 and TiO 2 -V 2 O 5 microspheres were prepared by non-hydrolytic solgel from TiCl 4 , VOCl 3 , and i Pr 2 O at 110°C without any solvent or additives. The samples were characterized by elemental analysis, X-ray diffraction, Raman spectroscopy, scanning electron microscopy, nitrogen physisorption, and impedance measurements. At low vanadium loadings, only TiO 2 anatase was detected, and V 2 O 5 scherbinaite was also detected at high vanadium loadings. The texture of the samples depended on the V loading, but all the samples appeared built of primary nanoparticles (&10-20 nm in size) that aggregate to form mesoporous micron-sized spheres. The lithium insertion properties of these materials were evaluated by galvanostatic measurements taken using coin-type cells, in view of their application as electrode for rechargeable Li-ion batteries. The mesoporous TiO 2 microspheres showed good performances, with a specific reversible capacity of 145 and 128 mAh g -1 at C/2 and C, respectively (C = 335.6 mA g -1 ), good coulombic efficiency, and a moderate capacity fade (6 %) from the 2nd to the 20th cycle at C/20. Although the addition of V effectively increased the electronic conductivity of the powders, the specific reversible capacity and cycling performances of the TiO 2 -V 2 O 5 samples were only minimally improved for a 5 at% V loading and were lower at higher V loading. Graphical AbstractTiCl 4 + x VOCl 3+(4+3x)/2 i Pr 2 O 110 °C 4 d Drying Calcination

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