Enhanced Conductivity of Anion-Exchange Membrane by Incorporation of Quaternized Cellulose Nanocrystal

High ion conductivity of anion-exchange membrane is essential for the operation of alkaline anion-exchange membrane fuel cell. In this work, we demonstrated an effective strategy to enhance the conductivity of anion-exchange membrane (AEM), by incorporation of quaternized cellulose nanocrystal (QCNC) for the first time. Morphology observation demonstrated a uniform distribution of QCNC within QPPO matrix, as well as a clear QCNC network, which led to significant enhancement in hydroxide conductivities of composite membranes, for example, 2 wt % QCNC/QPPO membrane possessed a conductivity of 160% (60 mS cm⁻¹, @80 °C) of that of QPPO. Furthermore, H₂/O₂ cell performance of membrane electrode assembly based on 2 wt % QCNC/QPPO AEM showed an excellent peak power density of 392 mV cm⁻² at 60 °C without back pressure, whereas that of neat QPPO AEM was only 270 mV cm⁻².