Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

Pattern Recognition and Machine Learning

This review describes recent advances in electrochemical impedance spectroscopy (EIS) with an emphasis on its novel applications to various electrochemistry-related problems. Section 1 discusses the development of new EIS techniques to reduce measurement time. For this purpose, various forms of multisine EIS techniques were first developed via a noise signal synthesized by mixing ac waves of various frequencies, followed by fast Fourier transform of the signal and the resulting current. Subsequently, an entirely new concept was introduced in which true white noise was used as an excitation source, followed by Fourier transform of both excitation and response signals. Section 2 describes novel applications of the newly developed techniques to time-resolved impedance measurements as well as to impedance imaging. Section 3 is devoted to recent applications of EIS techniques, specifically traditional measurements in various fields with a special emphasis on biosensor detections.

Electrochemical Impedance Spectroscopy

High-throughput density functional theory (HT DFT) is fast becoming a powerful tool for accelerating materials design and discovery by the amassing tens and even hundreds of thousands of DFT calculations in large databases. Complex materials problems can be approached much more efficiently and broadly through the sheer quantity of structures and chemistries available in such databases. Our HT DFT database, the Open Quantum Materials Database (OQMD), contains over 200,000 DFT calculated crystal structures and will be freely available for public use at http://oqmd.org
 . In this review, we describe the OQMD and its use in five materials problems, spanning a wide range of applications and materials types: (I) Li-air battery combination catalyst/electrodes, (II) Li-ion battery anodes, (III) Li-ion battery cathode coatings reactive with HF, (IV) Mg-alloy long-period stacking ordered (LPSO) strengthening precipitates, and (V) training a machine learning model to predict new stable ternary compounds.

Materials Design and Discovery with High-Throughput Density Functional Theory: The Open Quantum Materials Database (OQMD)

Electrochemical impedance spectroscopy has become a mature and well-understood technique. It is now possible to acquire, validate, and quantitatively interpret the experimental impedances. This chapter has been addressed to understanding the fundamental processes of diffusion and faradaic reaction at electrodes. However, the most difficult problem in EIS is modeling the electrode processes, which is where most of the problems and errors arise. There is an almost infinite variety of different reactions and interfaces that can be studied (corrosion, coatings, conducting polymers, batteries and fuel cells, semiconductors, electrocatalytic reactions, chemical reactions coupled with faradaic processes, etc.) and the main effort is now being applied to understanding and analyzing these processes. These applications will be the subject of a second review in a forthcoming volume in this series.

Electrochemical Impedance Spectroscopy and its Applications

Ionic liquids as electrolytes for Li-ion batteries—An overview of electrochemical studies

A theory is developed for the steady-state properties of passive films that form on metals and alloys in aqueous environments. This theory is based on the point defect model developed earlier, and predicts that they steady-state thickness of the barrier film and the log of the steady-state current will vary linearly with applied voltage. These relationships may be used to estimate empirical parameters that describe the dependencies of the potential drop across the barrier film/environment interface on the applied voltage and pH and to estimate kinetic parameters for dissolution of the film. If dissolution at the film-solution interface occurs very slowly, the primary passive film is envisaged to consist of a rigid oxide sublattice that transmit cations from the metal to a gel-like, precipitated upper layer. If dissolution at the barrier film/environment interface occurs rapidly, then a steady-state thickness is achieved by a balance between the rate of dissolution of the film at the film-solution interface and the rate of growth of the film into the underlying metal phase. Due to the outward movement of oxygen vacancies (i.e., inward movement of oxygen ions) through the barrier layer. The model is found to account for many experimental data that have beenmore » published in the literature on the quasi steady-state properties of passive films.« less

https://iopscience.iop.org/article/10.1149/1.2086949/pdf

Theory of Steady‐State Passive Films

Applications of Kramers—Kronig transforms in the analysis of electrochemical impedance data—III. Stability and linearity

Algorithms have been developed to apply the Kramers-Kronig transforms in the analysis of experimental electrochemical impedance data. The application of these algorithms is illustrated by transforming calculated impedance data for an electrical equivalent circuit, by transforming experimental data for TiO/sub 2-/coated carbon steel in HCl/KCl solution at 25/sup 0/C, and by analyzing data for an aluminum alloy in 4M KOH at 60/sup 0/C. These transforms, coupled with statistical techniques, provide a powerful means of evaluating the validity of impedance data with respect to spurious errors that are present in either the real or imaginary component, and with respect to system stability.

Application of Kramers‐Kronig Transforms in the Analysis of Electrochemical Impedance Data II . Transformations in the Complex Plane

A Kramers‐Kronig transform that is useful for validating electrochemical and corrosion impedance data is employed to calculate the polarization resistance from the frequency‐dependent imaginary component. Applications of the transform in the analysis of experimental impedance data for carbon steel in solution at ambient temperature and for aluminum and Al‐0.1P‐0.1In‐0.2‐Ga‐0.01Tl alloy in solution at 25°C are discussed.

Mirna Urquidi-Macdonald

Papers

Theory of Steady‐State Passive Films

Applications of Kramers—Kronig transforms in the analysis of electrochemical impedance data—III. Stability and linearity

Application of Kramers‐Kronig Transforms in the Analysis of Electrochemical Impedance Data II . Transformations in the Complex Plane

Application of Kramers‐Kronig Transforms in the Analysis of Electrochemical Systems I . Polarization Resistance

A coupled environment model for stress corrosion cracking in sensitized type 304 stainless steel in LWR environments