Electrochemistry for Materials Science

Walfried Plieth

• Editorial: Elsevier Science
• Año: 2008
• ISBN:
  9780080556253
• Categoría: Ciencias físicas
• Categoría: Química analítica

This book introduces the principles of electrochemistry with a special emphasis on materials science. This book is clearly organized around the main topic areas comprising electrolytes, electrodes, development of the potential differences in combining electrolytes with electrodes, the electrochemical double layer, mass transport, and charge transfer, making the subject matter more accessible.In the second part, several important areas for materials science are described in more detail. These chapters bridge the gap between the introductory textbooks and the more specialized literature. They feature the electrodeposition of metals and alloys, electrochemistry of oxides and semiconductors, intrinsically conducting polymers, and aspects of nanotechnology with an emphasis on the codeposition of nanoparticles.This book provides a good introduction into electrochemistry for the graduate student. For the research student as well as for the advanced reader there is sufficient information on the basic problems in special chapters. The book is suitable for students and researchers in chemistry, physics, engineering, as well as materials science.- Introduction into electrochemistry- Metal and alloy electrodeposition- Oxides and semiconductors, corrosion- Intrinsically conducting polymers- Codeposition of nanoparticles, multilayers

1

Electrolytes

Publisher Summary

The physical chemistry of electrolytic solutions is a special area of physical chemistry. The dissolution of a salt in water was described by Arrhenius as a dissociation of the salt in positive and negative ions of free mobility. This was originally a difficult suggestion to accept because salts were very stable substances. Therefore, for a long time the theory was called Arrhenius’ dissociation hypothesis. Later it became clear that the process was a reaction of the solvent water with the ions and that the ion–dipole interaction provided the necessary energy for the compensation of the strong lattice energies. The enthalpy of solution connected with the solution process is relatively small because it is just the difference between the lattice enthalpy and the enthalpy of solvation of cations and anions. The addition of gel-forming components (plasticizers) to polymer electrolytes produces gel like structures. Therefore, this type of ion-conducting polymers can also be described as gel polymer electrolytes. Gel polymer electrolytes can also be prepared, if a solution of a salt in an organic solvent is added to a polymer matrix (polyvinyl chloride, polyvinyl fluoride). The solvent dissolves in the polymer matrix and forms a gel like structure. The conductivity as well as the current density and rate of diffusion, etc., are determined by the mobility of the solvated ions in the polymer matrix. The transport constants are again proportional to the free volume in the polymer.

Conductivity is based on the free mobility of electrons in a metal, but some substances can also transport electricity without free electrons. Instead free mobile ions transport the current and are therefore called ionic conductors. The first ionic conductors were aqueous electrolytes. Later on, polymer and solid electrolytes were discovered and the name electrolytes became a synonym for ionic conductors.

The physical chemistry of electrolytic solutions is a special area of physical chemistry with a large number of reference literatures. Classical descriptions are given in the books of Harned and Owen¹ or Robinson and Stokes.² A more recent advanced treatment is found in the book of Barthel, Krienke, and Kunz.³ The special problems of ionic-conducting polymers and ionic solid electrolytes are described in various other reviews. Gray⁴ described polymer electrolytes. A classical treatment of ionic solid electrolytes is the book by Rickert⁵ or the Kudo and Fueki⁶ compilation. Because these materials are used in batteries and fuel cells, there is much literature for this research field including such detailed reviews in the book by Julien and Nazri.⁷ Another source for details and data compilations is the CRC Handbook of Solid State Electrochemistry.⁸

1.1 LIQUID ELECTROLYTE SOLUTIONS

The dissolution of a salt in water was described by Arrhenius⁹ as a dissociation of the salt in positive and negative ions of free mobility. This was originally a difficult suggestion to accept because salts were very stable substances. Therefore, for a long time the theory was called Arrhenius’ dissociation hypothesis. Later it became clear that the process was a reaction of the solvent water with the ions and that the...