Semiempirical model for determining PEM electrolyzer stack characteristics

A semiempirical equation was used to represent the performance characteristics of a 20-cell proton exchange membrane electrolyzer stack. The coefficients of the equation are the exchange current densities and membrane conductivity. These coefficients were determined using experimental data and a nonlinear curve fitting method. The anode exchange current density was found to be 1.65 x 10(-8) A cm(-2), the cathode exchange current density 0.09 A cm(-2), and the membrane conductivity 0.075 S cm(-1). External programmable power supplies were used to obtain the (I-V) characteristic curve of a commercial proton exchange membrane electrolyzer. Stack current, voltage, and system temperature were monitored while 1 A current steps were applied to the electrolyzes stack.