Hydro-Québec

About: Hydro-Québec is a government organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Electric power system & Dielectric. The organization has 2596 authors who have published 4433 publications receiving 100878 citations.

Ambient-Air Stable Lithiated Anode for Rechargeable Li-Ion Batteries with High Energy Density

Abstract: An important requirement of battery anodes is the processing step involving the formation of the solid electrolyte interphase (SEI) in the initial cycle, which consumes a significant portion of active lithium ions. This step is more critical in nanostructured anodes with high specific capacity, such as Si and Sn, due to their high surface area and large volume change. Prelithiation presents a viable approach to address such loss. However, the stability of prelithiation reagents is a big issue due to their low potential and high chemical reactivity toward O2 and moisture. Very limited amount of prelithiation agents survive in ambient air. In this research, we describe the development of a trilayer structure of active material/polymer/lithium anode, which is stable in ambient air (10–30% relative humidity) for a period that is sufficient to manufacture anode materials. The polymer layer protects lithium against O2 and moisture, and it is stable in coating active materials. The polymer layer is gradually dis...

High Substitution Rate in TiO2 Anatase Nanoparticles with Cationic Vacancies for Fast Lithium Storage

Abstract: Doping is generally used to tune and enhance the properties of metal oxides. However, their chemical composition cannot be readily modified beyond low dopant amounts without disrupting the crystalline atomic structure. In the case of anatase TiO2, we introduce a new solution-based chemical route allowing the composition to be significantly modified, substituting the divalent O2– anions by monovalent F– and OH– anions resulting in the formation of cationic Ti4+ vacancies (□) whose concentration can be controlled by the reaction temperature. The resulting polyanionic anatase has the general composition Ti1–x–y□x+yO2–4(x+y)F4x(OH)4y, reaching vacancy concentrations of up to 22%, i.e., Ti0.78□0.22O1.12F0.4(OH)0.48. Solid-state 19F NMR spectroscopy reveals that fluoride ions can accommodate up to three different environments, depending on Ti and vacancies (i.e. Ti3-F, Ti2□1-F, and Ti1□2-F), with a preferential location close to vacancies. DFT calculations further confirm the fluoride/vacancy ordering. When its...

Conforming and non-conforming current for attributing steady state power quality problems

Abstract: RMS fluctuations, waveform distortion and three-phase unbalance are some of the major aspects of power quality for which many measuring instruments exist today. This paper presents a concept for sharing the responsibility for these deteriorations between the electric utility and their customers. The sharing is based solely on measurements during power system operation.

Performance characteristics of dielectrics in the presence of space charge

Abstract: The short and long-term dielectric behavior of a number of representative electrical insulating systems is compared in the presence of space charge. Dielectric materials, used both in the communications and power application areas, are considered. In this overview, particular attention is given to thin inorganic films, organic solid-liquid and solid polymer systems as regards to the manner in which space charge affects their dielectric loss, voltage breakdown, treeing and electrical aging characteristics.