A simplified mathematical model to calculate the current distributions in bipolar electrochemical reactors is proposed. The current distributions are deduced from a combination of the voltage balance in the reactor with a voltage balance including the electrolyte inlet and outlet. Thus, equations to predict the effect of geometric and operational variables on the current distributions at the electrodes are reported. The parameters acting upon the current distributions were lumped into two dimensionless variables and their effects on the current distributions are discussed. The primary current distributions are obtained as a limiting case. Comparisons between calculated and experimental primary current distributions are reported. List of symbolsA transverse section of the electrolyte manifold (m 2 ) b i constant in the Tafel equation of the ith reaction (i= a or c) (V) C 1 constant given by Equation 7 (V) C 2 constant given by Equation 13 (V) d r mean relative deviation (%) e interelectrode distance (m)

The operation of lithium ion batteries in discharge and charge processes is addressed. A simple phenomenological model is developed to predict all variables values. A set of algebraic and differential equations is derived taking into account salt and lithium balances in electrodes, in the separator, and in particles. Balances are developed for finite volumes and appropriate average values of several variables such as concentrations, current densities, and electrochemical reaction rates are introduced. Definitions of current densities as volume fraction functions are critical issues in the computations. Experimental values taken from the literature for discharge processes are predicted very accurately. Constant salt concentration in the separator can be assumed and consequently, the model can be analytically solved. Charge and discharge times, initial cell capacity, lost capacity, and relaxation times are easily estimated from simple equations and cell parameters. The limiting processes taking place during cell discharge can be determined. Energy efficiency and capacity usage are quantified for cycles.

The secondary current distribution in an electrochemical stack with one bipolar electrode was experimentally determined and compared with the theoretical prediction according to the Laplace equation. A close agreement between both results is reported. The parameters acting upon the current distribution were lumped into a dimensionless variable, called the bipolar Wagner number, and its effect on the current distribution and predictive suitability of the theoretical treatment is discussed.

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1016/j.apenergy.2013.03.088Applied Energy, 111, pp. 853-861, 2013-06-21 Higher-capacity lithium ion battery chemistries for improved residential energy storage with micro-cogeneration Darcovich, K.; Henquin, E. R.; Kenney, B.; Davidson, I. J.; Saldanha, N.; Beausoleil-Morrison, I.