ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-06122019-102743


Tipo di tesi
Tesi di laurea magistrale
Autore
LAGNONI, MARCO
URN
etd-06122019-102743
Titolo
Modelling of electrochemical phenomena in lithium-air batteries with redox mediator and design optimisation of the cathode.
Dipartimento
INGEGNERIA DELL'ENERGIA, DEI SISTEMI, DEL TERRITORIO E DELLE COSTRUZIONI
Corso di studi
INGEGNERIA ENERGETICA
Relatori
relatore Prof. Nicolella, Cristiano
Parole chiave
  • optimisation
  • modelling
  • Li2O2 film
  • Li-air battery
  • embedded micro-channels
  • oxygen depletion
  • redox mediator
Data inizio appello
04/07/2019
Consultabilità
Non consultabile
Data di rilascio
04/07/2089
Riassunto
A mathematical model was developed for a Li-Air battery for both film and mediator mechanisms, and validated against experimental data, before being used to the design optimisation simulations. The dynamic behaviour of cathode porosity was determined by numerical solution of the governing, transport and reaction equations. The microscopic behaviour included the local mass transfer, the resistivity and the active surface morphology changing related to the Li2O2 film growth and the formation of Li2O2 particles driven by mediator mechanism. In the presence of mediator mechanism, the contribution of the convective velocity field to reactions may be relevant which is why we take into account that in the model. Simulations were performed first in 1D to model the electrochemical phenomena inside a flat type cell in which the problem could be assumed one-dimensional and then in 2D to perform the design optimisation of the cathode with embedded micro-channels to enhance oxygen supply. Thus, the optimisation process it’s about defining the better design of these channels, to reach better performance.
File