Full exam for Electrochemical Energy Conversion and Storage in the Energy Engineering degree programme at Politecnico di Milano. The document covers: EECS – Prof. A. Casalegno – 3rd September 2024 1 Standard EECS exam [duration 1 h 40 min] Students who passed TiP reduced number of questions marked with (TiP) [duration 1 h 10 min, remaining further means cancelling TiP mark] To upload https://forms.office.com/e/FtXDEZmsMC
Full exam for Electrochemical Energy Conversion and Storage in the Energy Engineering degree programme at Politecnico di Milano. The document covers: EECS – Prof. A. Casalegno – 3rd September 2024 1 Standard EECS exam [duration 1 h 40 min] Students who passed TiP reduced number of questions marked with (TiP) [duration 1 h 10 min, remaining further means cancelling TiP mark] To upload https://forms.office.com/e/FtXDEZmsMC
Import quality: text was extracted directly from the original document.
Representative passages recognised in different parts of the material. The full extracted text remains available to search, while this compact preview makes the page easier to read.
EECS – Prof. A. Casalegno – 3rd September 2024 1 Standard EECS exam [duration 1 h 40 min] Students who passed TiP reduced number of questions marked with (TiP) [duration 1 h 10 min, remaining further means cancelling TiP mark] To upload https://forms.office.com/e/FtXDEZmsMC maximum 5 single-side A4 pages – “file name” = PERSON_CODE.pdf Basic Part (4.5 points per question, minimum score 12) (TiP: 7.5 points) 1. Draw the electrical potential in the double layer of a PEMFC for the ORR in equilibrium 2. Write the Nernst-Plank equation for mass transport in a solid electrolyte with fixed charges 3. (TiP) Depict the charge curve of a Lithium-ion battery including a period at constant voltage, indicating also reasonable values for State of Charge and voltage Exercise (TiP) A PEMFC stack with 320 cells supplies at low power 17.5 kW and 0.3 A cm-2(LHV=120 MJ/kg). Assuming that 3% of H2 is wasted and its performance follows the reported polarization curve, estimate the efficiency and the power values at 1.8 A cm-2 (high power). Intermediate Part (3 points for each question) (TiP: 5 points) 1. Is the anode overpotential of a PEM electrolyzer positive or negative when O2 evolution reaction (OER) occurs? Demonstrate analyzing 𝐺" 2. (TiP) Voltage limits of batteries can reduce their actual available capacity during discharge: show how this effect is influenced by C-rate. ∆𝑉 0 𝑗 0.78 V 0.67 V 0.3 A cm-2 1.8 A cm-2 EECS – Prof. A. Casalegno – 3rd September 2024 2 Exercise (TiP) A Li-ion battery with nominal capacity of 50 Ah operates at ambient pressure and temperature, supplying 3.35 V during discharge at SoC=70% and C-rate=2 and requiring 3.9 V during charge at SoC=30% and C-rate=0.75. Assuming that: 1. Tafel kinetics is valid for both electrodes 2. ion and mass transport effects in…
First page of the document.
