(Bi,Sr)FeO (BSF) cathode materials doped with either Co, Ni or Mn are synthesized by an ethylene diamine tetra-acetic acid (EDTA)-citrate complexing method, and the effects of the doping level on the mixed electronic-ionic conductivity at various temperatures are studied up to 800 °C. The phase purity and solid solution limit are investigated by X-ray diffraction (XRD). The ionic conductivity is measured by the four-probe direct current (DC) method, the valence state of Fe and Mn by X-ray photoelectron spectroscopy (XPS), and the oxygen non-stoichiometry by differential thermo-gravimetric analysis (TGA). The doped ferrites show interesting electronic conductivity dependent on the testing temperature, implying two conductive mechanisms, either controlled by double exchange at lower temperatures or small polaron (electron-oxygen vacancy) conduction at temperatures greater than 400 °C. The results of Co-doped BSF (S50C20) show the best mixed conductivity among the ferrites, and this is used to assemble cells. The cell with a S50C20 cathode in the region of 600-800 °C is improved by 15% in maximum power density greater than the cell with LaSrCoFeO (LSCF) due to the balanced contribution from oxygen ions, vacancies and electrons.
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http://dx.doi.org/10.3390/ma9110922 | DOI Listing |
JAMA Otolaryngol Head Neck Surg
January 2025
Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, Tennessee.
Importance: Cochlear implants enable improvements in speech perception, but music perception outcomes remain variable. Image-guided cochlear implant programming has emerged as a potential programming strategy for increasing the quality of spectral information delivered through the cochlear implant to improve outcomes.
Objectives: To perform 2 experiments, the first of which modeled the variance in music perception scores as a function of electrode positioning factors, and the second of which evaluated image-guided cochlear implant programming as a strategy to improve music perception with a cochlear implant.
ACS Nano
January 2025
Soft Foundry Institute, Seoul National University, Seoul 08826, Republic of Korea.
Nickel-rich NCM cathode materials promise lithium-ion batteries with a high energy density. However, an increased Ni fraction in the cathode leads to complex phase transformations with electrode-electrolyte side reactions, which cause rapid capacity fading. Here, we show that an initial formation cycle at 0.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Shenzhen Key Laboratory of Intelligent Robotics and Flexible Manufacturing Systems, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
This study presents the development of a solar-driven thermally regenerative electrochemical cell (STREC) for continuous power generation. Key innovations include dual-function carbon-based electrodes for efficient solar absorption and electrochemical reactions, a transparent and ultrainsulating silica aerogel to maximize solar spectrum transmission while minimizing heat loss, and a compact heat exchanger to recover heat from hot cell streams. Under 1 sun conditions, the STREC achieves a power density of 912.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Beijing University of Chemical Technology, State Key Laboratory of Organic-Inorganic Composites, 15 North Third Ring Road East, 37830, Beijing, CHINA.
Polymers with strong electron-withdrawing groups (e.g., cyano-containing polymers) are attractive for a wide range of applications due to their high dielectric constant and outstanding electrochemical stability.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Sorbonne Université, Paris Brain Institute (ICM), INSERM, CNRS, UMR-1127, Mov'It, DreamTeam, Paris, France.
Background: Spectral power of slow rhythms in resting-state EEG increases along Alzheimer's disease (AD) continuum. Besides, recent studies have revealed 1) the importance of analyzing the aperiodic component of an EEG power spectrum and 2) the intrusions of sleep-like slow waves identifiable in wake EEG of animals and young adults. Importantly, the occurrence of these wake slow waves is known i) to increase after sleep deprivation, ii) to be associated with markers of sleepiness, and iii) to predict behavioral errors at different tasks.
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