login name
ITA english

Poster RSE 14001449

A 2D model of vanadium flow batteries: analysis of self-discharge due to vanadium ions crossover


IFBF2014 The International Flow Battery Forum 2014 1-2, Luglio-2014.

Request Document (856.95 KB, .pdf)

A. Casalegno (Politecnico di Milano), M. Zago (Politecnico di Milano), M. Scagliotti (RSE SpA), E. Rovera (Politecnico di Milano), A. Baricci (Politecnico di Milano), E. Micolano (RSE SpA)

RETI ATTIVE 2014 - Generazione distribuita e reti attive

In this work a two-dimensional model of a vanadium redox flow battery is developed, with the aim to analyse the behaviour of the battery and the effects of the self-discharge. The model is validated with experimental data measured on a real system.

The diffusion of vanadium ions across the membrane along with side reactions can have a significant impact on the capacity of the vanadium redox flow battery cycling. Diffusion of the vanadium ions from one electrode into the other will determine self-discharge reactions, leading to a capacity loss and an imbalance between the state-of-charge of the two half-cell electrolytes. A two-dimensional model is developed including a comprehensive description of mass and charge transport and conservation, coupled with a global kinetic model for reactions involving vanadium species.

Particular attention has been given to the description of vanadium ions transport through the membrane, in order to analyse the effect of self discharge on capacity loss in different operating conditions. Model simulations are compared with experimental data obtained by the operation of a real system to increase results reliability. Thanks to the developed model the effects of operating conditions and load profiles on self-discharge and performance are evaluated. The preliminary results suggest that the capacity loss caused by vanadium ions crossover could be reduced by properly varying the operating conditions as a function of the effective state of charge and load.

Related Links