An ONIOM and DFT study of water adsorption on rutile TiO2 (110) cluster

Density functional theory (DFT) calculations performed at ONIOM DFT B3LYP/6‐31G**‐MD/UFF level are employed to study molecular and dissociative water adsorption on rutile TiO₂ (110) surface represented by partially relaxed Ti₂₅O₃₇ ONIOM cluster. DFT calculations indicate that dissociative water adsorption is not favorable because of high activation barrier (23.2 kcal/mol). The adsorption energy and vibration frequency of both molecularly and dissociatively adsorbed water molecule on rutile TiO₂ (110) surface compare well with the values reported in the literature. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

A novel polyphosphazene with nitroxide radical side groups as cathode‐active material in Li‐ion batteries

A novel polyphosphazene carrying stable nitroxide aromatic radical groups as a pendant with four electrons involvement per repeating unit is synthesized. To do so, series of macromolecular substitution reactions of poly (dichlorophosphazene) with 3,5‐dibromophenol, 2‐methyl‐2‐nitrosopropane, and lead oxide, respectively, are performed. After characterization of the newly synthesized polymers by standard spectroscopic techniques (such as Fourier transform infrared [FT‐IR], nuclear magnetic resonance [NMR], or electron paramagnetic resonance [EPR]), the targeted polymer is further investigated as a cathode‐active material for rechargeable lithium‐ion batteries (LIBs). The cell delivered a good rate performance with a discharge capacity of 100 mAh/g at a C/2 current density over 500 cycles.     

Hydrothermal carbon spheres containing silicon nanoparticles: synthesis and lithium storage performance

Spherically shaped carbon/silicon nanocomposites have been obtained in a one-step procedure using hydrothermal carbonization of glucose in the presence of commercially available silicon nanoparticles and have been tested electrochemically as an anode material for lithium-ion batteries.     

Investigation of PZT-5H and PZT-8 type piezoelectric effect on cycling stability on Si-MWCNT containing anode materials

Silicon (Si) containing materials cannot be used in commercial lithium ion batteries due to the mechanical stress problem triggered by volume expansion during cycling. The high-volume change causes mechanical instability of Si anode materials during charging/discharging, resulting fast capacity fading. It is thought that piezoelectric materials can be a solution for the volume expansion problem because of their ability to generate electric field when pressure is applied on them. For this purpose, PZT-8 and PZT-5H type piezoelectric materials were mixed with silicon and multiwalled carbon nanotube (MWCNT) to obtain anode composites and tested electrochemically versus lithium metal. The piezoelectiric effect on the electrochemical activity of these anodes is investigated by preparing the anode composite without any piezoelectric material additive (Sample #3). At the end of the 50 charge/discharge cycles, the capacities reached 420 mAh/g, 300 mAh/g and 100 mAh/g for PZT-8-added, PZT-5H-added and no-PZT samples, respectively. These results showed that PZT addition improves capacity performance of Si-MWCNT anodes. Additionally, the obtained anode composites were characterized with X-ray diffraction and scanning electron microscopy.     

Ball mill–assisted synthesis of carbon-free SnSe nanoparticles for sodium-ion battery anodes

Journal of Solid State Electrochemistry - Tin selenide (SnSe) is a potential candidate for sodium-ion battery anodes owing to its high theoretical capacity, environmental benignity, and abundant...