New Fe2O3-Clay@C Nanocomposite Anodes for Li-Ion Batteries Obtained by Facile Hydrothermal Processes

Abstract

New iron-oxide-based anodes are prepared by an environmentally-friendly and low-cost route. The analysis of the composition, structure, and microstructure of the samples reveals the presence of a major hematite phase, which is accompanied by a certain concentration of an oxyhydroxide phase, which can act as a “lithium-reservoir”. By using sodium alginate as a binder, the synthesized anodes display superior electrochemical response, i.e., high specific capacity values and high stability, not only versus Li but also versus a high voltage cathode in a full cell. From these bare materials, clay-supported anodes are further obtained using sepiolite and bentonite natural silicates. The electrochemical performance of such composites is improved, especially for the sepiolite-containing one treated at 400 °C. The thermal treatment at this temperature provides the optimal conditions for a synergic nano-architecture to develop between the clay and the hematite nanoparticles. High capacity values of ~2500 mA h g−1 after 30 cycles at 1 A g−1 and retentions close to 92% are obtained. Moreover, after 450 cycles at 2 A g−1 current rate, this composite electrode displays values as high as ~700 mA h g−1. These results are interpreted taking into account the interactions between the iron oxide nanoparticles and the sepiolite surface through hydrogen bonds. The electrochemical performance is not only dependent on the oxidation state and particle morphology, but the composition is revealed as a key feature.

Low temperature conversion of levulinic acid into γ-valerolactone using Zn to generate hydrogen from water and nickel catalysts supported on sepiolite

“…The most relevant compositional and structural characteristics of the provided sepiolite were obtained from previous XRD, TGA, 29 Si-NMR, SEM and EDS data. 47 Thus, sepiolite showed an orthorhombic structure with cell parameters a ¼ 13.400, b ¼ 26.964 and c ¼ 5.2626Å, and did not present any secondary phase or impurities. Besides, this support had a surface area of 250 m 2 g À1 , which was slightly decreased aer reduction (242 m 2 g À1 ).…”

Inorganic Fillers in Composite Gel Polymer Electrolytes for High-Performance Lithium and Non-Lithium Polymer Batteries

“…Another limitation associated with LEs is the inevitable dendrite growth of lithium due to uneven current when using porous separators [ 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Furthermore, increasing the energy density in LIBs using high-voltage materials often leads to electrode degradation as it requires electrode–electrolyte compatibility [ 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Therefore, the development of new electrolytes is essential to overcome the aforementioned issues in LIB applications.…”

Biomimetic ZnO for Dye-Sensitized Solar Cells

“…The most commonly used substrate is fluoride-doped tin oxide (FTO)-coated glass. Thus, over the substrate, a nanocrystalline oxide layer is deposited, and a monolayer of the sensitizer is adsorbed onto the nanocrystalline oxide layer [ 10 ]. Photoexcitation of the sensitizer results in the injection of electrons into the conduction band of the oxide, leaving the sensitizer in an oxidized state.…”