(242d) Accurately Measuring the Ionic Conductivity of Ion-Exchange Membranes

Ion-exchange membranes (IEMs) play a critical role in regulating ion transport in established and emerging electrochemical technologies for water purification, energy generation, energy storage, and chemicals production. The membrane ionic conductivity, defined as the ohmic resistance normalized by membrane thickness and active area, is commonly used to quantify electric field-driven ion transport in IEMs. Accurate measurement of the membrane ionic conductivity is crucial for designing new membranes, establishing understanding of fundamental transport phenomena in membranes, and process modeling of electrochemical technologies. Various methods for measuring the ionic conductivity of IEMs have been reported, but there is no well-accepted standardized method. One of the primary challenges of measuring the membrane ionic conductivity is isolating the intrinsic membrane resistance from other resistances in the measurement cell. Failure to isolate the intrinsic membrane resistance can lead to significant inaccuracies in measurements, thereby impeding the advancement of the field. In this presentation, I will address the major challenges associated with measuring the ionic conductivity of IEMs. Furthermore, I will present recently established techniques that allow for the accurate measurement of the true ionic conductivity of IEMs. These techniques are straightforward, and they can be implemented using commonly available equipment.