Current distributions and electrocode shape changes in electrochemical systems
General Material Designation
[Book]
First Statement of Responsibility
J. Deconinck.
.PUBLICATION, DISTRIBUTION, ETC
Place of Publication, Distribution, etc.
Berlin <<>>
Name of Publisher, Distributor, etc.
Springer
Date of Publication, Distribution, etc.
1992
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
XV, 281 Seiten : Illustrationen, Diagramme.
SERIES
Series Title
Lecture notes in engineering, 75.
CONTENTS NOTE
Text of Note
1. The Current Distribution in Electro-Chemical Systems.- 1.1. Introduction.- 1.2. The electrode-electrolyte interphase.- 1.2.1. The equilibrium situation.- 1.2.2. Electrode reactions.- 1.2.3. The activation overpotential na.- 1.3. Transport equations in dilute solutions.- 1.3.1. The flux of a dissolved species.- 1.3.2. The current density.- 1.3.3. Conservation of mass.- 1.3.4. The Poisson equation or electroneutrality.- 1.3.5. The continuity equation.- 1.3.6. The Navier-Stokes equation.- 1.4. Solution of the transport equations in dilute solutions.- 1.4.1. Basic system of equations.- 1.4.2. The potential model.- 1.4.3. The concentration overpotential nc.- 1.5. The boundary conditions of the potential model.- 1.5.1. The boundary condition on-the walls.- 1.5.2. The boundary conditions on the electrodes.- 1.5.3. Additional boundary conditions.- 1.5.3.1. Resistive electrodes.- 1.5.3.2. Resistance involved by coatings.- 1.6. Types of current distributions.- 1.6.1. Introduction.- 1.6.2. The primary distribution.- 1.6.3. The secondary distribution.- 1.6.4. The tertiary distribution.- 1.6.4.1. Distribution over microprofiles.- 1.6.4.2. Distribution over macroprofiles.- 1.7. The Wagner number.- 1.8. Electrode shape change.- 1.8.1. Faraday's law.- 1.8.2. The current efficiency.- 1.8.3. Moving boundaries and electrochemical machining 4.- 1.8.4. Equations to solve.- 1.8.5. Electrode shape change between parallel electrodes.- 1.8.6. Electrochemical machining between plane parallel electrodes.- 1.9. Conclusion.- 2. Solution of the Potential Model.- 2.1. Introduction.- 2.2. Hypotheses and definitions.- 2.3. Weighted residual statements for the Laplace equation.- 2.4. Solution of current distributions with trial functions satisfying the field equations.- 2.5. Solution of current distributions with trial functions not satisfying the field equations.- 2.5.1. The finite difference method.- 2.5.2. The finite element method.- 2.5.3. The Newton-Raphson iteration associated with the finite element method.- 2.5.4. The method of straight lines.- 2.6. Solution of current distributions based on weight functions satisfying the field equation.- 2.6.1. The boundary element method.- 2.6.2. The Newton-Raphson iteration process in boundary elements.- 2.7. The physical interpretation of the integral equation.- 2.7.1. The potential generated by a charged surface.- 2.7.2. The potential generated by a double source density on a surface.- 2.7.3. Green's formula and source distributions.- 2.8. The outer normal convention..- 2.9. Indirect and regular boundary methods.- 2.10. Comparison of the treated weighted residual methods.- 2.11. Solution of current distributions by electric simulation.- 2.12. Conclusion.- 3. The Boundary Element Method to Solve Current Distributions.- 3.1. Introduction.- 3.2. Concretization of the boundary element method.- 3.2.1. Choice of used elements.- 3.2.1.1. Two-dimensional problems.- 3.2.1.2. Three-dimensional axisymmetric problems.- 3.2.2. Combination of regions.- 3.3. The overvoltage equations.- 3.3.1. The Butler-Volmer equation.- 3.3.2. The concentration overpotential.- 3.3.3. Linear and measured overpotentials.- 3.4. Solution of the non-linear system of equations.- 3.4.1. Solution of the linear system of equations 120 3.4-.2. Iteration techniques for non-linear systems.- 3.4.2.1. The successive substitution method.- 3.4.2.2. The Newton-Raphson iteration method - Global convergence conditions.- 3.4.2.3. Convergence criteria.- 3.4.2.4. A Newton-Raphson iteration versus a successive substitution.- 3.5. Examples.- 3.5.1. The Hull-cell.- 3.5.2. The influence of overpotentials on singularities.- 3.5.3. Industrial production-type cells.- 3.5.3.1. Two-dimensional cell composed of an electrode with open part and separator.- 3.5.3.2. A chlorine production cell.- 3.5.4. Current distribution in a circular hole.- 3.6. Copper electrorefining: numerical and experimental results.- 3.6.1. Electrochemical data 14..- 3.6.1.1. The electrolytic solution.- 3.6.1.2. The overvoltages.- 3.6.2. The cell geometry.- 3.6.3. The measuring equipment.- 3.6.4. The experimental procedure.- 3.6.5. Experimental results.- 3.6.5.1. Measurement 1: 6 cm interelectrode distance.- 3.6.5.2. Measurement 2: 12 cm interelectrode distance.- 3.6.6. Comparison with calculations.- 3.7. Conclusion.- 4. Electrode Shape Change.- 4.1. Introduction.- 4.2. The discretization with respect to time.- 4.2.1. The Euler method.- 4. 2.1.1. Convergence and accuracy.- 4.2.1.2. Stability.- 4.2.2. Higher-order integration schemes.- 4. 2.2.1. The predictor-corrector method (Heun).- 4.3. The electrode shape change algorithm.- 4.3.1. Electrodeposition.- 4. 3.1.1. Electrode next to an insulator: internal angle > ?/2.- 4.3.1.2. Electrode next to an insulator: internal angle ? ?/2.- 4.3.2. Electrode dissolution.- 4.3.3. Electrochemical machining.- 4.4. Examples.- 4.4.1. Electrodeposition in a Hull-cell.- 4.4.2. Deposition and dissolution in a cell with sinusoidal profile.- 4.4.3. Anodic leveling and electrochemical machining in a cell with irregular shape.- 4.4.4. ECM in a cell with hemispherical cathode.- 4.4.5. Conclusion: comments on the efficiency of the BEM.- 4.5. Electrodeposition and electrode dissolution in copper electrorefining. Numerical and experimental results.- 4.5.1. Electrochemical data.- 4.5.2. The cell geometry.- 4.5.3. The measuring equipment.- 4.5.4. The experimental procedure.- 4.5.5. Experimental results and comparison with calculations.- 4.5.6. The influence of a screen.- 4.6. Conclusion.- 5. General Conclusion.- References.- Appendices.- A.1.1 Primary current distribution along a free cathode in parallel with an anode and perpendicular to an insulating boundary.- A.1.2 Primary current distribution along an L-shaped cathode.- A.1.3 Primary current distribution along a cathode being in line with an insulating boundary.- A.2 Solution of the potential model using trial functions satisfying the field equation: example.- A.3.1 Analytic integration of integrals involved by the two-dimensional boundary element method using straight elements.- A.3.2 Evaluation of integrals involved by the boundary element method used to solve axisymmetric potential problems.- A.4 The global Newton convergence of the potential problem with non-linear boundary conditions.