scholarly journals Analysis of Electrochemical Impedance Spectroscopy on Zinc-Air Batteries Using the Distribution of Relaxation Times

Batteries ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 56
Author(s):  
Robert Franke-Lang ◽  
Julia Kowal
Keyword(s):  
Electrochemical Impedance ◽  
Storage Systems ◽  
Regularization Parameter ◽  
Relaxation Times ◽  
Quality Criterion ◽  
Key Technology ◽  
New Methods ◽  
Impedance Data ◽  
First Time ◽  
Zinc Air Batteries

Zinc-air batteries could be a key technology for higher energy densities of electrochemical energy storage systems. Many questions remain unanswered, however, and new methods for analyses and quantifications are needed. In this study, the distribution of relaxation times (DRT) based on ridge regression was applied to the impedance data of primary zinc-air batteries in a temperature range of 253 K and 313 K and at different State-of-Charges for the first time. Furthermore, the problem of the regularization parameter on real impedance spectroscopic measurements was addressed and a method was presented using the reconstruction of impedance data from the DRT as a quality criterion. The DRT was able to identify a so far undiscussed process and thus explain why some equivalent circuit models may fail.

scholarly journals Optimized Process Parameters for a Reproducible Distribution of Relaxation Times Analysis of Electrochemical Systems

Batteries ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 43 ◽  
Author(s):  
Markus Hahn ◽  
Stefan Schindler ◽  
Lisa-Charlotte Triebs ◽  
Michael A. Danzer
Keyword(s):  
Distribution Function ◽  
Electrochemical Impedance ◽  
Regularization Parameter ◽  
Relaxation Times ◽  
Measurement Data ◽  
Complex Impedance ◽  
Lithium Ion ◽  
Parameter Study ◽  
Model Free ◽  
The Impact

The distribution of relaxation times (DRT) analysis offers a model-free approach for a detailed investigation of electrochemical impedance spectra. Typically, the calculation of the distribution function is an ill-posed problem requiring regularization methods which are strongly parameter-dependent. Before statements on measurement data can be made, a process parameter study is crucial for analyzing the impact of the individual parameters on the distribution function. The optimal regularization parameter is determined together with the number of discrete time constants. Furthermore, the regularization term is investigated with respect to its mathematical background. It is revealed that the algorithm and its handling of constraints and the optimization function significantly determine the result of the DRT calculation. With optimized parameters, detailed information on the investigated system can be obtained. As an example of a complex impedance spectrum, a commercial Nickel–Manganese–Cobalt–Oxide (NMC) lithium-ion pouch cell is investigated. The DRT allows the investigation of the SOC dependency of the charge transfer reactions, solid electrolyte interphase (SEI) and the solid state diffusion of both anode and cathode. For the quantification of the single polarization contributions, a peak analysis algorithm based on Gaussian distribution curves is presented and applied.

scholarly journals Analysis of La4Ni3O10±δ-BaCe0.9Y0.1O3-δ Composite Cathodes for Proton Ceramic Fuel Cells

2021 ◽  
Vol 11 (8) ◽  
pp. 3407
Author(s):  
Francisco J. A. Loureiro ◽  
Devaraj Ramasamy ◽  
Vanessa C. D. Graça ◽  
Laura I. V. Holz ◽  
Sergey M. Mikhalev ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Composite Electrode ◽  
Electrochemical Impedance ◽  
Electronic Conductivity ◽  
Relaxation Times ◽  
Composite Cathode ◽  
Conducting Phase ◽  
Proton Conducting ◽  
Impedance Data ◽  
Composite Cathodes

Layered Ruddlesden-Popper (RP) lanthanide nickelates, Lnn+1NinO3n+1 (Ln = La, Pr, and Nd; n = 1, 2, and 3) have generated great interest as potential cathodes for proton conducting fuel cells (PCFCs). The high-order phase (n = 3) is especially intriguing, as it possesses the property of a high and metallic-type electronic conductivity that persists to low temperatures. To provide the additional requirement of high ionic conductivity, a composite electrode is here suggested, formed by a combination of La4Ni3O10±δ with the proton conducting phase BaCe0.9Y0.1O3-δ (40 vol%). Electrochemical impedance spectroscopy (EIS) is used to analyse this composite electrode in both wet (pH2O ~ 10−2 atm) and low humidity (pH2O ~ 10−5 atm) conditions in an O2 atmosphere (400–550 °C). An extended analysis that first tests the stability of the impedance data through Kramers-Kronig and Bayesian Hilbert transform relations is outlined, that is subsequently complemented with the distribution function of relaxation times (DFRTs) methodology. In a final step, correction of the impedance data against the short-circuiting contribution from the electrolyte substrate is also performed. This work offers a detailed assessment of the La4Ni3O10±δ-BaCe0.9Y0.1O3-δ composite cathode, while providing a robust analysis methodology for other researchers working on the development of electrodes for PCFCs.

A Bayesian View on the Hilbert Transform and the Kramers-Kronig Transform of Electrochemical Impedance Data: Probabilistic Estimates and Quality Scores

2020 ◽  
Author(s):  
Jiapeng Liu ◽  
Ting Hei Wan ◽  
Francesco Ciucci
Keyword(s):  
Power Generation ◽  
Electrochemical Impedance Spectroscopy ◽  
Hilbert Transform ◽  
Electrochemical Impedance ◽  
The Self ◽  
Impedance Data ◽  
The Hilbert Transform ◽  
Validation Tests ◽  
Self Consistency ◽  
Mathematical Relations

<p>Electrochemical impedance spectroscopy (EIS) is one of the most widely used experimental tools in electrochemistry and has applications ranging from energy storage and power generation to medicine. Considering the broad applicability of the EIS technique, it is critical to validate the EIS data against the Hilbert transform (HT) or, equivalently, the Kramers–Kronig relations. These mathematical relations allow one to assess the self-consistency of obtained spectra. However, the use of validation tests is still uncommon. In the present article, we aim at bridging this gap by reformulating the HT under a Bayesian framework. In particular, we developed the Bayesian Hilbert transform (BHT) method that interprets the HT probabilistic. Leveraging the BHT, we proposed several scores that provide quick metrics for the evaluation of the EIS data quality.<br></p>

scholarly journals Efficient TALEN-mediated gene knockin at the bovine Y chromosome and generation of a sex-reversal bovine

2021 ◽  
Author(s):  
Ming Wang ◽  
ZhaoLin Sun ◽  
Fangrong Ding ◽  
Haiping Wang ◽  
Ling Li ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Nuclear Transfer ◽  
Sex Reversal ◽  
Practical Application ◽  
Transcription Activator ◽  
New Methods ◽  
Fetal Fibroblasts ◽  
Male Phenotype ◽  
Solid Foundation ◽  
First Time

AbstractFunctional elucidation of bovine Y-chromosome genes requires available genome editing technologies. Meanwhile, it has yet to be proven whether the bovine Sry gene is the main or single factor involved in the development of the male phenotype in bovine. Here, we efficiently knocked out four Y-linked genes (Sry, ZFY, DDX3Y, and EIF2S3Y) in bovine fetal fibroblasts (BFFs) with transcription activator-like effector nucleases (TALENs) individually. Furthermore, we used TALEN-mediated gene knockin at the Sry gene and generated a sex-reversal bovine by somatic cell nuclear transfer (SCNT). The resulting bovine had only one ovary and was sterile. We demonstrate, for the first time, that the Sry gene is an important sex-determining gene in bovine. Our method lays a solid foundation for detecting the biology of the bovine Y chromosome, as it may provide an alternative biological model system for the study of mammalian sex determination, and new methods for the practical application in agricultural, especially for sex predetermination.

scholarly journals Computation of distribution of relaxation times by Tikhonov regularization for Li ion batteries: usage of L-curve method

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Paul ◽  
P. W. Chi ◽  
Phillip M. Wu ◽  
M. K. Wu
Keyword(s):  
Tikhonov Regularization ◽  
Relaxation Times ◽  
Detection Methods ◽  
Similar Process ◽  
Fredholm Integral Equations ◽  
Li Ion Batteries ◽  
Impedance Data ◽  
Curve Method ◽  
Li Ion ◽  
Process Detection

AbstractIn this paper, the distribution of relaxation times (DRTs) functions are calculated numerically in Matlab for synthetic impedance data from single parallel $$RC$$ RC circuit and two parallel $$RC$$ RC circuits connected in series, experimental impedance data from supercapacitors and α-LiFeO2 anode based Li ion batteries. The quality of the impedance data is checked with the Kramers–Krönig (KK) relations. The DRTs are calculated within the KK compatible regime for all the systems using Tikhonov regularization (TR) method. Here we use a fast and simple L-curve method to estimate the TR parameter (λ) for regularization of the Fredholm integral equations of first kind in impedance. Estimation of the regularization parameters are performed effectively from the offset of the global corner of the L-curve rather than simply using the global corner. The physical significances of DRT peaks are also discussed by calculating the effective resistances and capacitances coupled with peak fitting program. For instance, two peaks in the DRTs justify the electrical double layer capacitance and ion diffusion phenomena for supercapacitors in low to intermediate frequencies respectively. Moreover, the surface film effect, Li/electrolyte and electrode/electrolyte charge transfer related processes are identified for α-LiFeO2 anode based Li-ion batteries. This estimation of the offset of the global corner extends the L-curve approach coupled with the Tikhonov regularization in the field of electrochemistry and can also be applied in similar process detection methods.

scholarly journals Determination of the Distribution of Relaxation Times by Means of Pulse Evaluation for Offline and Online Diagnosis of Lithium-Ion Batteries

Batteries ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 36
Author(s):  
Erik Goldammer ◽  
Julia Kowal
Keyword(s):  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Sampling Rate ◽  
Relaxation Times ◽  
Low Frequency ◽  
Lithium Ion ◽  
Battery Management ◽  
Time Constants ◽  
Time Domain Data ◽  
Aging Study

The distribution of relaxation times (DRT) analysis of impedance spectra is a proven method to determine the number of occurring polarization processes in lithium-ion batteries (LIBs), their polarization contributions and characteristic time constants. Direct measurement of a spectrum by means of electrochemical impedance spectroscopy (EIS), however, suffers from a high expenditure of time for low-frequency impedances and a lack of general availability in most online applications. In this study, a method is presented to derive the DRT by evaluating the relaxation voltage after a current pulse. The method was experimentally validated using both EIS and the proposed pulse evaluation to determine the DRT of automotive pouch-cells and an aging study was carried out. The DRT derived from time domain data provided improved resolution of processes with large time constants and therefore enabled changes in low-frequency impedance and the correlated degradation mechanisms to be identified. One of the polarization contributions identified could be determined as an indicator for the potential risk of plating. The novel, general approach for batteries was tested with a sampling rate of 10 Hz and only requires relaxation periods. Therefore, the method is applicable in battery management systems and contributes to improving the reliability and safety of LIBs.

ONLINE EXHIBITION METROLEXPO-2020. ACCURATE MEASUREMENTS ARE THE BASIS OF QUALITY AND SAFETY

2021 ◽  
pp. 50-57
Author(s):  
V. I. Matveev
Keyword(s):  
Measuring Equipment ◽  
Technical Diagnostics ◽  
Quality And Safety ◽  
New Methods ◽  
Analytical Studies ◽  
Functional Control ◽  
First Time

The article summarizes the results of the MetrolExpo exhibition, which was held for the first time online. The event focused on instrumentation-demonstration and discussion of the possibilities of modern measuring equipment, analysis of new methods and technologies of accurate measurements that have appeared in recent years. The latest developments, devices and systems for conducting measurements, tests, technical diagnostics, analytical studies, production and functional control from the largest Russian and foreign manufacturers were demonstrated.

scholarly journals Protection of Petroleum Pipeline Carbon Steel Alloys with New Modified Core-Shell Magnetite Nanogel against Corrosion in Acidic Medium

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Gamal A. El Mahdy ◽  
Ayman M. Atta ◽  
Amro K. F. Dyab ◽  
Hamad A. Al-Lohedan
Keyword(s):  
Carbon Steel ◽  
Sulfonic Acid ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Core Shell ◽  
Magnetite Nanoparticle ◽  
Potassium Peroxydisulfate ◽  
Redox Initiator ◽  
Initiator System ◽  
First Time

New method was used to prepare magnetite nanoparticle based on reduction of Fe(III) ions with potassium iodide to produce Fe3O4nanoparticle. The prepared magnetite was stabilized with cross-linked polymer based on 2-acrylamido-2-methylpropane sulfonic acid (AMPS to prepare novel core-shell nanogel. In this respect, Fe3O4/poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) magnetic nanogels with controllable particle size produced via free aqueous polymerization at 65°C have been developed for the first time. The polymer was crosslinked in the presence of N,N-methylenebisacrylamide (MBA) as a crosslinker and potassium peroxydisulfate (KPS) as redox initiator system. The structure and morphology of the magnetic nanogel were characterized by Fourier transform infrared spectroscopy (FTIR) and transmission and scanning electron microscopy (TEM and SEM). The effectiveness of the synthesized compounds as corrosion inhibitors for carbon steel in 1 M HCl was investigated by various electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed enhancement in inhibition efficiencies with increasing the inhibitor concentrations. The results showed that the nanogel particles act as mixed inhibitors. EIS data revealed thatRctincreases with increasing inhibitor concentration.

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