Évaluation des dégâts sur les cultures céréalières via l'étude du régime alimentaire du moineau domestique Passer domesticus L. dans la plaine du Gharb (Maroc)

Dans le but de quantifier les dégâts causés par les populations du moineau domestique Passer domesticus L. sur les cultures céréalières, on s'est proposés de décrire le régime et le comportement trophique de cette espèce au niveau de la plaine du Gharb. En effet, une population de ce moineau domestique cantonnée dans la Ferme expérimentale du Gharb de l'Institut Agronomique et Vétérinaire Hassan II, a permis d'aborder l'écologie alimentaire de cette espèce. Un suivi régulier de cette population, à l'aide des "filets japonais", a montré que les adultes sont essentiellement granivores (Triticum sativum 29.65 %, Hordeum vulgare 74.53 %). Les oisillons au nid sont insectivores, à base de Coléoptères. Les jeunes à l'envol se nourissent essentielement des graines de céréales

Microstructure and ionic conductivity of LLTO thin films: Influence of different substrates and excess lithium in the target

The deposition of single phase Li3xLa2/3 - xTiO3 (LLTO) thin films remains very challenging. The growth of the perovskite phase is in competition with the insulating La2Ti2O7 phase when prepared at high oxygen pressure by PLD. Nevertheless, we have achieved epitaxial growth of LLTO on different (001) oriented substrates such as LaAlO3, SrTiO3 and MgO despite a large lattice mismatch of up to + 8.8%. We also determined the percentage of lithium excess in the target necessary to reach a maximum ionic conductivity. However, the presence of the blocking La2Ti2O7 phase strongly hinders the lithium ion migration and reduces the total conductivity compared to bulk properties.F.A. would like to thank the support of the Ministry of Industry of the Basque Country for their financial support through the Etortek program untitled Energigune´13.Peer Reviewe

Investigating the dendritic growth during full cell cycling of garnet electrolyte in direct contact with Li metal.

All-solid-state batteries including a garnet ceramic as electrolyte are potential candidates to replace the currently used Li-ion technology, as they offer safer operation and higher energy storage performances. However, the development of ceramic electrolyte batteries faces several challenges at the electrode/electrolyte interfaces, which need to withstand high current densities to enable competing C-rates. In this work, we investigate the limits of the anode/electrolyte interface in a full cell that includes a Li-metal anode, LiFePO4 cathode, and garnet ceramic electrolyte. The addition of a liquid interfacial layer between the cathode and the ceramic electrolyte is found to be a prerequisite to achieve low interfacial resistance and to enable full use of the active material contained in the porous electrode. Reproducible and constant discharge capacities are extracted from the cathode active material during the first 20 cycles, revealing high efficiency of the garnet as electrolyte and the interfaces, but prolonged cycling leads to abrupt cell failure. By using a combination of structural and chemical characterization techniques, such as SEM and solid-state NMR, as well as electrochemical and impedance spectroscopy, it is demonstrated that a sudden impedance drop occurs in the cell due to the formation of metallic Li and its propagation within the ceramic electrolyte. This degradation process is originated at the interface between the Li-metal anode and the ceramic electrolyte layer and leads to electromechanical failure and cell short-circuit. Improvement of the performances is observed when cycling the full cell at 55 °C, as the Li-metal softening favors the interfacial contact. Various degradation mechanisms are proposed to explain this behavior

Mechanical failure of garnet electrolytes during Li electrodeposition observed by in-operando microscopy

Metallic Li anodes are key to reaching high energy densities in next-generation solid-state batteries, however, major problems are the non-uniform deposition of Li at the interface and the penetrative power of Li metal during operation, which cause failure of the ceramic electrolyte, internal short-circuits and a premature end of battery life. In this work, we explore the anode-electrolyte interface instability of a Li metal-garnet electrolyte system during Li electrodeposition, and its implications for mechanical fracture, Li metal propagation, and electrolyte failure. The degradation mechanism was followed step-by-step during in-operando electrochemical cycling using optical and scanning electron microscopy. High amounts of Li electrodeposition in a localized zone of the interface lead to ceramic fracture followed by an electrode-to-electrode electrical connection via a conductor Li metal filament. This work enables deeper understanding of battery failure modes in all-solid-state batteries containing a ceramic electrolyte membrane

Silk fibroin and sericin polymer blends for sustainable battery separators

Natural polymers are a promising alternative for reducing the environmental impact of batteries. For this reason, it is still necessary to study their behavior and implement its use in these devices, especially in separator membranes. This work reports on new separator membranes based on silk fibroin (SF) and silk sericin (SS) prepared by salt leaching method. The effect of the different SS relative content on the physiochemical properties of the membranes and on the electrochemical performance of the corresponding batteries with lithium iron phosphate (LFP) as cathodes has been reported. It is observed that the increasing of SS content leads to a decrease of the overall crystallinity of the membranes. All SF/SS membranes presented a well-defined porosity above 75% with a uniform distribution of interconnected micropores. The electrolyte uptake and the ionic conductivity are dependent on the relative SS content. The addition of 10 wt% of SS into SF membranes, induce a high ionic conductivity of 4.09 mS.cm−1 and high lithium transference number (0.52), due to the improvement of the Li+ ions conduction paths within the blended structure. Charge/discharge tests performed in Lithium/C-LFP half-cells reveal a discharge capacity of 85 mAh.g−1 at 2C after 100 cycles for batteries with a SF/SS separator, containing a 10 wt% of SS, which suggests a stabilizing effect of Sericin on discharge capacity. Further, a 50% and 35% of capacity of retention and capacity fade, respectively, is observed. The presented SF/SS membrane show high electrochemical stability, being suitable for implementation in a next generation of sustainable battery systems. This could allow the SS valorization considering that 150,000 tons of SS are abandoned each year, reducing the contamination of environmental effluents.The authors thank the Fundação para a Ciência e Tecnologia (FCT) for financial support under the framework of Strategic Funding grants UID/FIS/04650/2020, UID/EEA/04436/2020, and UID/QUI/0686/2020 and under projects POCI-01-0145-FEDER-028157 and PTDC/FIS-MAC/ 28157/2017 funded by national funds through FCT and by the ERDF through the COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI). The authors also thank the FCT for financial support under FCT investigator contracts CEECIND/00833/ 2017 (RG) and 2020.04028.CEECIND (C.M.C.). Financial support from the Basque Government Industry Department under the ELKARTEK 2018 program (KK-2018/00098) is acknowledged. The authors thank for technical and human support provided by SGIker (UPV/EHU/ ERDF, EU)