Mxenes as inorganic fillers for the construction of poly(aryl piperidinium) anion exchange membranes with microphase separation structures to enhance ionic conductivity

The improvement of ionic conductivity and alkali stability of anion exchange membranes(AEMs) has been the focus of research. The abundant functional groups on the surface of inorganic nanomaterials tend to form a rich hydrogen bonding network, which reduces the activation energy and improves the ionic conductivity. In this paper, the prepared HF-Ti3C2Tx was used as a filler in a quaternized poly(aryl piperidinium) (QPAP) matrix to enhance the performance of the membrane electrode assembly of an anion exchange membrane water electrolyzers (AEMWE). With the addition of MXenes, the mechanical properties of the composite membrane improved significantly (from 12.13 MPa to 27.85 MPa). At 80 °C, the ionic conductivity of QPAP-HM-0.7 was as high as 159.4 mS cm−1. The results showed that the functional groups on the surface of MXenes and the polymer matrix successfully constructed a hydrogen bonding network within the membrane, forming a hydrophilic and hydrophobic microphase separation structure. In addition, the composite membranes prepared by doping HF-Ti3C2Tx obtained good alkali stability (conductivity retention of more than 85 % after 720 h immersion at 80 °C in 1 M NaOH) and dimensional stability, which proved that MXenes is an effective filler to improve the membrane properties.