• embedded micro-channels
• Li-air battery
• Li2O2 film
• modelling
• optimisation
• oxygen depletion
• redox mediator

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.