This report demonstrated the first study on the use of a new 2D nanomaterial (Mxene) for enhancing membrane performance of intermediate temperature (>100 °C) polymer electrolyte membrane fuel cells (ITPEMFCs). In this study, a typical Ti3C2Tx-MXene was synthesized and incorporated into polybenzimidazole (PBI)-based membranes by using a solution blending method. The composite membrane with 3 wt% Ti3C2Tx-MXene showed the proton conductivity more than 2 times higher than that of pristine PBI membrane at the temperature range of 100 °C–170 °C, and led to substantial increase in maximum power density of fuel cells by ∼30% tested at 150 °C. The addition of Ti3C2Tx-MXene also improved the mechanical properties and thermal stability of PBI membranes. At 3 wt% Ti3C2Tx-MXene, the elongation at break of phosphoric acid doped PBI remained unaffected at 150 °C, and the tensile strength and Young’s modulus was increased by ∼150% and ∼160%, respectively. This study pointed out promising application of MXene in ITPEMFCs.

Proton conductors operated in over 200°C have received great interest for proton exchange membrane fuel cells (PEMFCs). The tetravalent metal ion pyrophosphates materials (MP2O7) are considered as the suitable conductor electrolyte, and the mesopores structure MP2O7 are attractive, because capillary condensation of water molecules occurs at relatively low relative humidity, allowing for fast transport of protons without excessive humidification. In this study, we report meso-SnP2O7, which is synthesized from mesoporous SnO2, as promising solid electrolyte candidate for PEMFCs in a temperatures range of 180°C to 280°C. Furthermore, graphite oxide (GO) is incorporated with the meso-SnP2O7 to further improve the proton conductivity and water retention. The structure and phase stability of the membranes are analysed by X-ray diffraction (XRD) and thermos-gravimetric analysis (TGA). The microstructure morphology of SnP2O7 particles and pellets is analysed by transmission electron microscope (TEM) and scanning electron microscopy (SEM). The obtained particles and pores size of Meso-SnP2O7 are characterized by the ETA potential meter and BET. The Meso-SnP2O7 and Meso-SnP2O7/GO electrolytes exhibit the high proton conductivities of 0.15 S cm -1 and 0.17 S cm -

Proton conductors capable of operating in high temperature range (over 180oC) has attracted worldwide attention. The promising inorganic membranes candidates CeP2O7 and Ce3+ doped CeP2O7 were used between 160 degrees C and 280 degrees C for Proton exchange membrane fuel cell (PEMFC) in this study. The structure and phase stability were analyzed by X-ray diffraction, Fourier transform infrared (FTIR), XPS (ESCALAB250Xi) and thermogravimetric analysis (TGA), and also the microstructure morphology was analyzed by scanning electron microscopy (SEM). The CeP2O7 and Ce3+ doped CeP2O7 composite membranes exhibited high proton conductivity of 0.008 S cm(-1) and 0.0095S cm(-1) at 200 degrees C, respectively. The peak power densities of Ce3+ doped CeP2O7 membrane were 23.5 mW cm(-2) at 180 degrees C and 26.6 mW cm(-2) at 200 degrees C, respectively.

Ti3C2Tx, a typical MXene, was incorporated into alumina (Al2O3) to obtain ceramic composites and its effects on their microstructures and mechanical properties were investigated. The investigation results showed that MXene was well-dispersed in the ceramic matrix and significantly reinforced alumina. At 2wt% Ti3C2Tx, the fracture toughness, bending strength and hardness was improved by ~300%, ~150%, ~300%, respectively. The toughening mechanisms associated with crack deflection induced by Ti3C2Tx were discussed.

Proton conductors operating at a high temperature condition have attracted great attention for intermediate temperature proton exchange membrane fuel cells (PEMFCs).Inorganic electrolyte membrane fabricated from Cs substituted Phosphomolybdic acid (CsXH3-XPMo12O40) is considered as a suitable potential candidates for membranes without a liquid phase for PEMFCs using between 160 to 280°C.Graphite oxide is incorporated with this solid material to improve the proton conductivity, and the activation energy is also calculated by the Arrhenius equation.The CsXH3-XPMo12O40/GO composite electrolyte exhibits the high proton conductivities of 1.7*10 -3 S cm -1 at 280°C.