Publications by authors named "Camille Douard"

Fast charging is a critical concern for the next generation of electrochemical energy storage devices, driving extensive research on new electrode materials for electrochemical capacitors and micro-supercapacitors. Here we introduce a significant advance in producing thick ruthenium nitride pseudocapacitive films fabricated using a sputter deposition method. These films deliver over 0.

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By selecting two electroactive species immobilized in a layered double hydroxide backbone (LDH) host, one able to act as a positive electrode material and the other as a negative one, it was possible to match their capacity to design an innovative energy storage device. Each electrode material is based on electroactive species, riboflavin phosphate (RF) on one side and ferrocene carboxylate (FCm) on the other, both interleaved into a layered double hydroxide (LDH) host structure to avoid any possible molecule migration and instability. The intercalation of the electroactive guest molecules is demonstrated by X-ray diffraction with the observation of an interlayer LDH spacing of about 2 nm in each case.

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The purpose of this study is to highlight the influence of some fabrication parameters, such as mass loading and porosity, which are not really elucidated and standardized during the realization of electrodes for supercapacitors, especially when using metal oxides as electrode materials. Electrode calendering, as one stage during the fabrication of electrodes, was carried out step-by-step on manganese dioxide electrodes to study the decreasing porosity effect on the electrochemical performance of a MnO symmetric device. One other crucial parameter, the mass loading, which has to be understood and well used for realistic supercapacitors, was investigated concurrently.

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Article Synopsis
  • The study focuses on nanosized FeWO electrode material, exploring how Fe and W metal cations contribute to its pseudocapacitive properties through fast Faradaic reactions.
  • Operando X-ray absorption spectroscopy is used in real-time experiments to better understand the charge storage mechanisms and the roles of the cations during the electrode's cycling.
  • Findings reveal that the Fe/Fe redox couple is crucial for charge storage, while W serves as a spectator, allowing for clearer differentiation between Faradaic and capacitive behaviors, and showcasing the potential for improving high-capacitance materials.
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