Electrochemical Energy Conversion and Storage

Synthetic program:

Il corso fornisce le conoscenze di base della fisica per la modellizzazione e la progettazione di sistemi elettrochimici per la conversione e l'accumulo di energia, ed include i seguenti aspetti: la termodinamica di una cella elettrochimica, la cinetica delle reazioni elettrochimiche, i fenomeni di trasporto nell'elettrolita e negli elettrodi porosi, tecniche di misura e diagnostica. Dopo un'analisi delle tecnologie elettrochimiche per la conversione e l'accumulo di energia, verranno in seguito approfondite le caratteristiche e le problematiche dei seguenti sistemi per applicazioni stazionarie e automobilistiche, per mezzo di attività sperimentali e modelli fisici, con particolare attenzione ai fenomeni di trasporto: batterie con e senza elettrolita liquido, batterie a flusso, celle a combustibile polimeriche, celle a combustibile ad ossido solido, elettrolizzatori.

Physics of electrochemical processes
Basic concepts. Historical overview of electrochemical devices. Working principles of a fuel cell and a battery. Description of the electrochemical double layer. Thermodynamics of an electrochemical cell. Definition of electrochemical potential and thermodynamic activity. Nernst Equation for ideal and real systems. Kinetics of electrochemical reaction. Electrochemical reaction rate, definition of activation polarization. Analysis of single-step, two-step, parallel step reactions. Concentration polarization. Ion transfer in electrolyte. Ionic transport by migration and diffusion, description of the Nernst-Planck equation, the electro-neutrality approximation, the effect of convective transport. Mass transport phenomena in porous electrodes. Fick and Knudsen diffusion phenomena in porous media. The effect of convective transport, Darcy’s law. Electrochemical measurement and diagnostic techniques. Polarization curve, cycling and linear voltammetry. The electrochemical impedance spectroscopy and its interpretation. Degradation long term and accelerated test. Description of advanced in-situ and ex-situ techniques.

Electrochemical energy technology
State of art of electrochemical energy conversion and storage technology for automotive, stationary and portable applications. Batteries with aqueous and non aqueous electrolyte. General features. Lithium ion battery. State of charge and efficiency. Charging and discharging. Heat transfer. Flow Batteries. General features. Independency of power and energy. Redox couples. Effect of fluid dynamics on mass transport. Migration and cross-contamination effect. Polymer Electrolyte Fuel Cell. General features. Transport phenomena in catalyst layers. Degradation mechanisms. Water and heat management. Solid Oxide Fuel Cell. General features. Internal reforming. Heat and mass transfer. Degradation mechanisms. Reverse operation, co-electrolysis. Water Electrolyser. General features. Two-phase transport phenomena. Pressurized and variable load operation. Gas crossover.