Topics
Here is a table of contents for the Electrochemical Species Band Diagram (ESBD) project.
As a main prerequisite, please read the intro page for the definition and motivation for species voltage .
The landscape:
- Species voltage - the fundamentals of species voltage .
- Equilibrium - electrodes and reactions.
- Lithium ion batteries - An application spotlight.
- How to read an ESBD - a field guide to every line and symbol on the diagrams.
Materials I - Dilute Charge Carriers:
- Solutions - Concentrations, standard states . Ion activities.
- Semiconductors - Conduction/valence bands as levels, electrons/holes as ion analogs.
- Charge neutrality and mass action - Doping, Donnan potential, and the common-ion effect.
- Bipolar membranes and pn junctions (application spotlight) - The visual twin of water-splitting and electron-hole pair generation.
Materials II - Electrostatics, Transport, and Complex Materials:
- Basic electrostatics - Debye screening and the local charge neutrality approximation.
- Capacitance - Dielectric and chemical capacitance; the capacitive divider.
- Basic transport - Ohm's law, concentration polarization, and liquid junction potentials.
- Saturation (application spotlight) - The common reason why current saturates in transistors and electrochemical processes.
- Other conductors - Metals, fast ionic conductors, and mixed conductors.
Redox and electrode potentials:
- Half-reactions - Electrons "in solution": redox and the Nernst equation in land. Standard electrode potentials as floating levels .
- Electrode potential - One electrode: visualizing , overpotential, and mixed potentials.
- Reference electrodes & cells - Reference electrodes, full cells, liquid junction potentials, and the "absolute" vacuum reference.
- Interface kinetics - The current–overpotential law: Butler–Volmer as the exponential interface element, Tafel, the diode connection, and Marcus–Gerischer.
Application highlights: (Planned, coming soon! Follow my twitter for updates.)
- Redox-flow batteries: one redox couple per tank, exchanging across a membrane.
- Acid–base flow batteries: a bipolar-membrane stack whose interior runs entirely on ions; tanks in series as mutual chemical capacitors.
- Solid oxide fuel cells: landscape.
- Cell biology: The proton motive force as a drop; the electron transport chain as a cascade.
- Lead-Acid Batteries: A system where the electrolyte is a reactant.
- Electroplating: A kinetic-driven process.
- Corrosion: A mixed-potential, non-equilibrium system.
The rabbit holes -- appendices, advanced topics, notes:
Thermodynamics:
- Understanding electrochemical potential - Why is the real, indivisible chemical potential — and why that makes (and band diagrams) work.
- Reaching any $V_i$ - Are "real voltages"? How to access each one in practice.
- Offsets galore - An interactive tour of every arbitrary convention in the framework — and which ones actually move anything.
- Non-ideal solutions - Focussing on technical difficulties of single-ion activities.
- Chemical capacitance matrices - Mutual chemical capacitance (thermodynamic) vs internal chemical capacitance (extrathermodynamic), as capacitance matrices.
Messy electrostatics:
- $\phi$ under the microscope - Which ? The microscopic potential, its smoothed average, and the working convention: why ions answer to none of them.
- Vacuum levels - The one honest potential: real, measurable, and ending at the surface.
- Inhomogeneities and electrostatics - Per-species quasi-electric fields: what replaces "the electric field" inside materials. Plus the beyond-the-simple-case catalog.
Appendices:
- Standard state data - Numerical data for ionic solutes' values in water.
- Traditional electrochemistry, translated - A Rosetta Stone: standard symbols and equations in terms.
- About - How this project came about.