Pressure-induced abnormal ionic–polaronic–ionic transition sequences in AgBr

2018 ◽  
Vol 20 (11) ◽  
pp. 7492-7497 ◽  
Author(s):  
Jia Wang ◽  
Yonghao Han ◽  
Hao Liu ◽  
Guozhao Zhang ◽  
Cailong Liu ◽  
...  
Keyword(s):  
Ionic Conductor ◽  
Impedance Spectra ◽  
Transition Sequence ◽  
Abnormal Pressure ◽  
Ionic Transition

From impedance spectra measurements, an abnormal pressure-induced ionic–polaronic–ionic transition sequence was found in the ionic conductor AgBr.

Performance of Ba0.5Sr0.5Co0.8Fe0.2O3-δ-Ag Composite Cathode Materials for IT-SOFCs

2011 ◽  
Vol 311-313 ◽  
pp. 2309-2314 ◽  
Author(s):  
Wen Xia Zhu ◽  
Zhe Lü ◽  
Le Xin Wang ◽  
Xiao Yan Guan ◽  
Xin Yan Zhang
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Electrochemical Impedance ◽  
Composite Cathode ◽  
Solid Oxide ◽  
Electrode Polarization ◽  
Impedance Spectra ◽  
Electrochemical Impedance Spectra ◽  
Composite Cathodes ◽  
Reduced Temperature ◽  
Resistance Value

°Abstract. In order to develop new cathodes for reduced temperature SOFCs, Ba0.5Sr0.5Co0.8Fe0.2O3-δ-Ag composite cathode was investigated in intermediate-temperature Solid Oxide Fuel Cells (IT-SOFCs). The XRD results suggested that no chemical reactions between BSCF and Ag in the composite cathode were found. The resistance measurements showed that the addition of Ag into BSCF improved electrical conductivity of pure BSCF, and the improved conductivity resulted in attractive cathode performance. In addition, electrochemical impedance spectra exhibited the better performance of BSCF-Ag composite cathodes than pure BSCF, e.g., the polarization resistance value of BSCF-Ag was only 0.36Ω cm2 at 650°C, which was nearly 80% lower than that of BSCF electrode. Polarization curves showed the overpotential decreased with the addition of Ag. The current density value of BSCF-Ag was 0.88Acm-2 under –120mV, about five times of that BSCF measured at 650°C. As a summary, compared to a pure BSCF cathode, it was found that adding Ag in the cathode enhanced the BSCF performance significantly.

Exceeding three-electron reactions in Na3+2xMn1+xTi1-x(PO4)3 NASICON Cathode with High Energy Density for Sodium-ion Batteries

2021 ◽  
Author(s):  
Jiefei Liu ◽  
Kangshou Lin ◽  
Yu Zhou ◽  
Yu Zhou ◽  
Xianhua Hou ◽  
...  
Keyword(s):  
Energy Density ◽  
High Energy ◽  
Ionic Conductor ◽  
Sodium Ion ◽  
High Energy Density ◽  
Sodium Ion Batteries ◽  
Nasicon Structure

The sodium super ionic conductor (NASICON) materials are considered as the attractive cathode in sodium-ion batteries. Although the three-electron reactions in Na3MnTi(PO4)3 have greatly enhanced the capacity of NASICON-structure materials,...

scholarly journals Hysteresis Analysis of Hole-Transport-Material-Free Monolithic Perovskite Solar Cells with Carbon Counter Electrode by Current Density–Voltage and Impedance Spectra Measurements

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 48
Author(s):  
Syed Afaq Ali Shah ◽  
Muhammad Hassan Sayyad ◽  
Jinghua Sun ◽  
Zhongyi Guo
Keyword(s):  
Time Delay ◽  
Current Density ◽  
Power Conversion ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Impedance Spectra ◽  
Voltage Measurement ◽  
Sweep Time ◽  
Measurement Protocol ◽  
A Current

Due to the tremendous increase in power conversion efficiency (PCE) of organic–inorganic perovskite solar cells (PSCs), this technology has attracted much attention. Despite being the fastest-growing photovoltaic technology to date, bottlenecks such as current density–voltage (J–V) hysteresis have significantly limited further development. Current density measurements performed with different sweep scan speeds exhibit hysteresis and the photovoltaic parameters extracted from the current density–voltage measurements for both scan directions become questionable. A current density–voltage measurement protocol needs to be established which can be used to achieve reproducible results and to compare devices made in different laboratories. In this work, we report a hysteresis analysis of a hole-transport-material-free (HTM-free) carbon-counter-electrode-based PSC conducted by current density–voltage and impedance spectra measurements. The effect of sweep scan direction and time delay was examined on the J–V characteristics of the device. The hysteresis was observed to be strongly sweep scan direction and time delay dependent and decreased as the delay increased. The J–V analysis conducted in the reverse sweep scan direction at a lower sweep time delay of 0.2 s revealed very large increases in the short circuit current density and the power conversion efficiency of 57.7% and 56.1%, respectively, compared with the values obtained during the forward scan under the same conditions. Impedance spectroscopy (IS) investigations were carried out and the effects of sweep scan speed, time delay, and frequency were analyzed. The hysteresis was observed to be strongly sweep scan direction, sweep time delay, and frequency dependent. The correlation between J–V and IS data is provided. The wealth of photovoltaic and impendence spectroscopic data reported in this work on the hysteresis study of the HTM-free PSC may help in establishing a current density–voltage measurement protocol, identifying components and interfaces causing the hysteresis, and modeling of PSCs, eventually benefiting device performance and long-term stability.

Deep Neural Network Battery Impedance Spectra Prediction by Only Using Constant-Current Curve

2021 ◽  
Author(s):  
Yanzou Duan ◽  
Jinpeng Tian ◽  
Jiahuan Lu ◽  
Chenxu Wang ◽  
Weixiang Shen ◽  
...  
Keyword(s):  
Neural Network ◽  
Deep Neural Network ◽  
Constant Current ◽  
Impedance Spectra ◽  
Current Curve

Impedance eduction for uniform and multizone acoustic liners

2021 ◽  
pp. 1475472X2110238
Author(s):  
Michael G Jones ◽  
Douglas M Nark ◽  
Brian M Howerton
Keyword(s):  
Impedance Spectra ◽  
International Forum ◽  
Acoustic Liners ◽  
Prony Method ◽  
Research Challenges ◽  
Test Conditions ◽  
Acoustic Liner ◽  
Flow Impedance ◽  
Grazing Flow ◽  
Computationally Expensive

This paper presents results for five uniform and two multizone liners based on data acquired in the NASA Langley Grazing Flow Impedance Tube. Two methods, Prony and CHE, are used to educe the impedance spectra for each of these liners for many test conditions. The Prony method is efficient and generally provides accurate results for uniform liners, but is not well suited for multizone liners. The CHE method supports assessment of both uniform and multizone liners, but is much more computationally expensive. The results from these liners demonstrate the efficacy of both eduction methods, but also clearly demonstrate that sufficient attenuation is required to support accurate impedance eduction. For the liners considered in this study, the data indicate approximately 3 dB attenuation is needed for each zone of a multizone liner in order to ensure quality impedance eduction results. This study was conducted in response to two acoustic liner research challenges in support of a collaboration of multiple national laboratories under the International Forum for Aviation Research.

Phase transition sequence in the chiral compound 10FHBBBM7* studied by Raman scattering

1999 ◽  
Vol 26 (12) ◽  
pp. 1805-1811 ◽  
Author(s):  
Yu. I. Yuzyuk ◽  
S. Sarmento ◽  
P. Simeao Carvalho ◽  
A. Almeida ◽  
Filipa Pinto ◽  
...  
Keyword(s):  
Phase Transition ◽  
Raman Scattering ◽  
Chiral Compound ◽  
Transition Sequence
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