86461 - Electromechanical Energy Storage and Conversion

Academic Year 2020/2021

Learning outcomes

In this course students: 1. Learn the fundamentals of cell electrochemistry, the materials characteristics and main issues related to the manufacturing process. 2. Classify the possible cell chemistry and technology in relation to the range of application in the automotive sector. 3. Learn modelling methodology for representing the cell output characteristic and the variability of cell parameters. 4. Understanding main issues related to the pack formation by series/parallel connection of cells. 5. Learn the sizing criteria for a battery pack. 6. Understand the most innovative electrochemical storage technology. 7. Learn the fundamental principle and sizing method for energy storage systems not based on electrochemical batteries: supercapacitors and flywheel.

Course contents

The course is divided in two parts that will be teached by two different professors:

Prof.ssa Francesca Soavi, Electrochemistry of energy storage and conversion cells, 3 CFU

Prof. Davide Pontara, Batteries in Traction Applications, 3 CFU

The teachers will follow the overall program reported here after.

Ion lithium batteries. Technology

Basic cell chemistry.

Chemical-physical properties and reactivity of the cell fundamental components: cathode, anode, separator and electrolyte.

Cell operation, cell stability, cell safety, cell ageing.

Characteristic of ancillary parts: collector, insulation, case, protection systems.

Standard protocols for cell evaluation.

Selection of proper battery chemistry (LIFePO4, Li-metal oxides) for possible automotive application (BEV, HEV).

Characteristics of the ion-lithium batteries manufacturing sector and of the corresponding market.

Classification of energy storage system for automotive application in relation to the vehicle type (BEV, HEV, PHEV). Battery positioning on Ragone plot.

Ion lithium batteries. Model

Basic and precise model of a ion-lithium cell using concentrated parameters.

State of charge (SOC) estimation.

Influence on cell parameters of: SOC, lifetime, temperature, cycles.

Modification of output characteristic and usable capacity due to the parameter variation.

Performance evaluation method for ion -lithium cells.

End of Charge and End of Discharge condition.

Battery pack and Battery Management Systems (BMS)

Battery pack and battery management system (BMS)

Criteria for selecting optimal pack voltage level.

Pack sizing and series/parallel connection of cells.

Analysis of the effect of cell parameter dispersion in determining End of Charge and end of Discharge process.

Cell equalization principle. Active and passive equalization methods and circuits.

Functional requirements for the BMS and interfacing characteristics with other powertrain components.

Possible BMS topologies.

Thermal control of battery pack

BMS safety function and standard requirements for management of ion-lithium cells

Other energy storage systems

Storage system with high power density: supercapacitors and flywheel (KERS).

General characteristics and main issues related to the application of supercaps and flywheel to the automotive sector. Simplified model at component level. Design criteria of a high power storage system based on these technologies.

Readings/Bibliography

Indications about reference texts (all available in the main libraries) will be done during the course. Papers and review articles will be also provided.

Teaching methods

Frontal lessons: basic and technological aspects of electrochemical energy conversion systems such as lithium batteries and supercapacitors.

Training and laboratory activities related to the realization of numerical model of several ion lithium cells and experimental laboratory test for determining the cell parameters.

Assessment methods

The final exam is oral and based on a program topic chosen by the student and two or more questions on the main program topics.The exam aims to determine both the acquisition of expected knowledge by the course program and the student's ability to find links among the covered topics, also using the reference material provided by the teacher.

Teaching tools

Power point presentations used during the lessons and any research material will be provided to the students in electronic format via Internet. The power point presentations used during the course will be uploaded on the university site before the corresponding lesson. Students are invited to print the presentations and bring them to classes.

Office hours

See the website of Francesca Soavi

See the website of Davide Pontara