Introduction to Electrochemical Science and Engineering

Due to the increasing demand for power generation and the limited nature of fossil fuels, new initiatives for energy development based on electrochemical energy conversion systems are springing up around the world. Introduction to Electrochemical Science and Engineering describes the basic operational principles for a number of growing electrochemical engineering-related technologies, including fuel cells, electrolyzers, and flow batteries. Inspired by the author’s more than ten years of experience teaching undergraduate electrochemistry-related courses at Penn State University, this essential text: Ensures a fundamental knowledge of the core concepts of electrochemical science and engineering, such as electrochemical cells, electrolytic conductivity, electrode potential, and current-potential relations related to a variety of electrochemical systems.

Develops the initial skills needed to understand an electrochemical experiment and successfully evaluate experimental data without visiting a laboratory. Provides more than 360 conceptual and numerical problems distributed over nine quizzes and nine video-based assignments. Contains a number of illustrative case studies related to novel electrochemical energy conversion systems. Promotes an appreciation of the capabilities and applications of key electrochemical techniques. Solutions manual and electronic figure files available with qualifying course adoption. Introduction to Electrochemical Science and Engineering is an ideal textbook for undergraduate engineering and science students and those readers in need of introductory-level content. Furthermore, experienced readers will find this book useful for solidifying their electrochemical background

Acknowledgments

Introduction

Author

Objectives

Formation of Electrolyte Solutions

Electrolyte Concentration and Concentration Scales

Conversion Equations for the Concentration of Solutions

Chemical Potential

Standard Chemical Potential and Activity Coefficient on Different Concentration Scales

Chemical Potential of Solvent and Solute in Electrolyte Solution

Activity and Activity Coefficient

Activity Coefficient of Electrolyte and an Ion

Chemical Potential and Gibbs Energy of Formation

Debye–Hückel Theory of Dilute Electrolyte Solutions

Calculation of Activity Coefficient Using Debye–Hückel Theory

Calculated and Observed Activity Coefficients

Mean Activity Coefficient in Concentrated Aqueous Solutions

Speciation in Weak Electrolytes

pH of Aqueous Solutions

pH of Buffer Solutions

Suggested pH of Standard Solutions

Summary

References

Objectives

Basic and Derived SI Units

Electrochemical Cell (System)

Electrolytic and Galvanic Cells

Electrochemical Diagrams (Traditional)

New Electrochemical Diagrams

Faraday’s Law of Electrolysis

Fundamental Constants

Water Electrolysis

Ohm’s Law

Kirchhoff’s Law

Electrochemical Cells with Transfer

Daniell Cell in Galvanic Mode

Daniell Cell in Electrolytic Mode

Cell Potential-Current Dependence

Summary

References

Objectives

Types of Electric Conductivity

Significance of Ion Conductive Materials for Electrochemical Engineering

Origin of Ionic Conductivity

Conductance and Conductivity of an Electrolyte

Electric Conductivity of Pure Water

Conductance by Direct and Alternating Currents

Electrode/Electrolyte Interface

Extracting the Electrolyte Resistance

Conductivity Measurements

Molar and Equivalent Conductivity

Kohlrausch’s Law and Limiting Conductivity

Additivity of Electrolyte Limiting Conductivity

Transport Numbers

Diffusion and Hydration of Ions in Infinitely Diluted Solution

Proton Conductivity

Walden’s Rule

Summary

References

Objectives

Equilibrium Thermodynamics and Electrochemistry

Equilibrium between Phases in Electrochemical Cell

Galvani Potential of the Hydrogen Electrode

Gibbs Energy of Reaction and Equilibrium Electrode Potential

Nernst Equation

Standard Hydrogen Electrode

Ag/AgCl Reference Electrode

Harned Cell

Electrochemical Series

Calculation of Equilibrium Potential of Daniell Cell

Nernst Equation for Typical Electrodes

Another Example of Estimating of E⁰ and E

Calculation of E⁰ at Elevated Temperature

Temperature Dependence of the Standard Electrode Potential

Temperature Dependence of Open Circuit and Decomposition Potentials

Potential-pH (Pourbaix) Diagram

Summary

References

Objectives

Potentiometric Measurements

Commercial Ag/AgCl Reference Electrode

Commercial Calomel Reference Electrode

pH Glass Electrode

Liquid Junction (Diffusion) Potential

Henderson Equation

Calculation of the Diffusion Potential

Minimization of the Diffusion Potential in a Cell

Kinds of Potentiometry

Measurement of the Standard Electrode Potential

Measurement of pH

Combined pH/Reference Electrode Sensor and pH Meter

Summary

References

Objectives

Concept of Electrochemical Cell Overpotential

Overpotential of a Single Electrode

Polarization Curve of a Single Electrode

Mechanism of Electrochemical Reaction

Charge Transfer Overpotential: Butler–Volmer Equation

Symmetry Coefficient, β

Exchange Current Density, j_o

Experimental Data on the Exchange Current Density and Symmetry Coefficient

Simplifications of Butler–Volmer Equation

Tafel Equation

Volcano Plot

Concentration Overpotential

Mass Transfer Overpotential

Generalized Butler–Volmer Equation

Summary

References

Objectives

Transport Processes in Electrochemical Systems

Current–Time Dependence at Constant Potential (Potentiostatic Regime)

Concentration–Time Dependence at Constant Current (Galvanostatic Regime)

Effect of Hydrodynamics (Fluid Mechanics) on Electrochemical Reaction

Rotating Disk Electrode and Limiting Current

Rotating Disk Electrode Electrochemical Cell

Cyclic Voltammetry Background

Cyclic Voltammetry of Fe(CN)^3–₆ /Fe(CN)^4–₆ Couple

Summary

References

Objectives

Main Types of Electrochemical Energy Conversion Systems

Principle Design of a Fuel Cell

Main Kinds of Fuel Cells

Electrochemistry of Full Cells

Three-Phase Boundary Issue

New Electrochemical Diagrams for Fuel Cells

Polarization Curves of PEMFC and SOFC

Efficiency of Fuel Cell vs. Heat Engine

Total Efficiency of Fuel and Electrolytic Cells

Heat Balance in Fuel and Electrolytic Cells

Summary

References

Objectives

Origin of Electrochemical Corrosion

Pourbaix Diagram in Corrosion Science

Polarization Curve of Metal Corrosion

Corrosion Potential and Current Density

Rate of Electrochemical Corrosion

Corrosion Protection

Kinds of Corrosion

Summary

References

Codata Values of the Fundamental Physical Constants

Physical Constants of Inorganic Compounds

Standard Thermodynamic Properties of Chemical Substances

Thermodynamic Properties as a Function of Temperature

Thermodynamic Properties of Aqueous Ions

Ionization Constant of Water as a Function of Temperature and Pressure

Electrical Conductivity of Water

Electrical Conductivity of Aqueous Solutions

Standard KCl Solutions for Calibrating Conductivity Cells

Molar Conductivity of Aqueous HCl

Equivalent Conductivity of Electrolytes

Ionic Conductivity and Diffusion at Infinite Dilution

Electrochemical Series

Dissociation Constants of Inorganic Acids and Bases

Dissociation Constants of Organic Acids and Bases

Activity Coefficients of Acids, Bases, and Salts

Mean Activity Coefficients of Electrolytes

Concentrative Properties of Aqueous Solutions

Aqueous Solubility of Inorganic Compounds at Various Temperatures

Solubility Product Constants

Solubility of Common Salts at Ambient Temperatures

Thermophysical Properties of Water and Steam at Temperatures up to 100°C

Vapor Pressure and Other Saturation Properties of Water at Temperatures up to 100°C

van der Waals Constants for Gases

Vapor Pressure of Saturated Salt Solutions

Electrical Resistivity of Pure Metals

Composition of Seawater and Ionic Strength on Molality Scale at Various Salinities S in Parts per Thousand

Error Function

Periodic Table of Elements

Appendix A: Quizzes

Appendix B: Video-Based Assignments

Index

Serguei N. Lvov is a professor of energy and mineral engineering, a professor of materials science and engineering, and a director of the Electrochemical Technologies Program at the EMS Energy Institute of The Pennsylvania State University, University Park, USA. His areas of research include electrochemistry, thermodynamics, material sciences, and environmental sciences. He is the author of more than 100 peer-reviewed papers, 2 books, 6 book chapters, and 2 US patents.