Functionalized MXene acts as a crosslinking agent to construct new anion exchange membranes for anion exchange membrane water electrolysis

As one of the core components of anion exchange membrane water electrolyser (AEMWE), the performance of anion exchange membrane (AEM) has a direct impact on the application effect of the water electrolyzer. Chemical cross-linking method is an effective way to solve the problem of balancing membrane dimensional stability and ionic conductivity and improve mechanical properties. However, the crosslinked network brings hindrance to the ionic transport rate and causes the loss of ionic conductivity, having a direct impact on the application effect of water electrolysis. In this paper, a series of Poly(biphenyl-co-m-triphenyl-piperidine) (PBMP) based on composite AEMs are prepared by functionalized modification of MXene with high electrical conductivity as an inorganic cross-linking agent, and the electrical conductivity of MXene overcomes the hindrance of cross-linking on ion transport. Inorganic crosslinkers are classified into hexane hydrocarbon crosslinkers (6-NH 2 -Alk-Ti 3 C 2 T x ) and ethane hydrocarbon crosslinkers (2- NH 2 -Alk-Ti 3 C 2 T x ). The AEMs prepared with 2-NH 2 -Alk-Ti 3 C 2 T x crosslinker exhibit higher ionic conductivity (112.0 mS cm −1 ) due to a sharper microphase separation morphology. The presence of a crosslinked network within the membrane reduces the swelling ratio of the membrane (80 °C, 1.2 %) and improves the mechanical properties (from 29.2 MPa to 55.3 MPa). In addition, the AEMWE prepared by PBMP-0.46-2-NH 2 -Alk-Ti 3 C 2 T x (PBMP-0.46–2M) membrane reaches 760 mA cm −2 at 2.0 V, 70 °C in 1 M KOH solution. Therefore, it is feasible to realize AEMs prepared with functionalized MXene as crosslinker and filler for application in electrolysis cells.