To investigate the effect of acidic nanoparticles on proton conductivity, permeability, and fuel-cell performance, a commercial Nafion^® 117 membrane was impregnated with zirconium phosphates (ZrP) and sulfated zirconium (S-ZrO₂) nanoparticles. As they are more stable than other solid superacids, sulfated metal oxides have been the subject of intensive research. Meanwhile, hydrophilic, proton-conducting inorganic acids such as zirconium phosphate (ZrP) have been used to modify the Nafion^® membrane due to their hydrophilic nature, proton-conducting material, very low toxicity, low cost, and stability in a hydrogen/oxygen atmosphere. A tensile test, water uptake, methanol crossover, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to assess the capacity of nanocomposite membranes to function in a fuel cell. The modified Nafion^® membrane had a higher water uptake and a lower water content angle than the commercial Nafion^® 117 membrane, indicating that it has a greater impact on conductivity. Under strain rates of 40, 30, and 20 mm/min, the nanocomposite membranes demonstrated more stable thermal deterioration and higher mechanical strength, which offers tremendous promise for fuel-cell applications. When compared to 0.113 S/cm and 0.013 S/cm, respectively, of commercial Nafion^® 117 and Nafion^® ZrP membranes, the modified Nafion^® membrane with ammonia sulphate acid had the highest proton conductivity of 7.891 S/cm. When tested using a direct single-cell methanol fuel cell, it also had the highest power density of 183 mW cm⁻² which is better than commercial Nafion^® 117 and Nafion^® ZrP membranes.

Anion exchange membrane fuel cells (AEMFCs) are considered superior to their counterpart proton exchange fuel cells due to their many advantages. Both fuel cells use membranes as polymer electrolytes to improve fuel-cell properties and power output. This work evaluates a series of imidazolium-quaternized poly(2,6-dimethyl-1,4-phenylene oxide) (ImPPO) functionalized zeolitic imidazole framework-8 (ZIF-8) (ImPPO/ZIF-8) as anion exchange membrane (AEM) electrolytes in a direct methanol alkaline fuel cell. FTIR and ¹H NMR were used to confirm the successful membrane fabrication. SEM and TGA were used to study the morphological and thermal stability properties of the ImPPO/ZIF-8 membranes. The AEMs obtained in this work had contact angles ranging from 55.27–106.73°, water uptake from 9–83%, ion exchange capacity (IEC) from 1.93–3.15 mmol/g, and ion conductivity (IC) from 1.02–2.43 mS/cm. The best-performing membrane, ImPPO/3%ZIF-8, showed a water uptake of up to 35% at 80 °C, a swelling ratio of 15.1% after 72 h, IEC of 4.06 mmol/g, and IC of 1.96 mS/cm. A power density of 158.10 mW/cm² was obtained. This makes ZIF-8 a good prospect as a filler for enhancing membrane properties.

Membranes made up of composite materials have shown promising advantages for application in alkaline fuel cell anion exchange membranes. In this study, a general method is employed to improve the overall performance and properties of alkaline anion exchange membranes by making use of polyethersulfone quaternized with imidazolium groups and blended with imidazolium functionalized graphene oxide inorganic filler (ImGO). The inorganic filler blended with the polymer matrix yielded better ionic transport, with 73.2 mS·cm⁻¹ being the highest ion conductivity for the polymer membrane with 0.5% ImGO content, which is higher than that of the QPES parent material. The 0.5% ImGO content also showed better swelling ratio, water uptake, alkaline stability, ion exchange capacity and alkaline stability in comparison to other membranes. Furthermore, it also exhibited 130 mW·cm⁻² peak power.

A membrane is a critical component of an Al‐air battery because it provides ion transport and ensures separation of the anode and cathode. In this work, a series of quaternized polysulfone (QPSF) membrane blended with ZSM‐5 zeolite anion exchange membranes (AEMs) were fabricated by solution casting to be used as separators in Al‐air batteries. All membranes showed moderate to excellent water uptake (WU), swelling ratio, ion exchange capacity (IEC), and ion conductivity measurements (IC). Incorporation of ZSM‐5 zeolite resulted in hydrophilicity and improved WU, with QPSF/3 wt% ZSM‐5 retaining 114% water at room temperature. The QPSF/3 wt% ZSM‐5 composite membrane was the best performing membrane with the IEC and the highest hydration number of 2.85 mmol g⁻¹, 2.23, and a maximum of IC of 229.85 mS cm⁻¹ at room temperature, respectively. QPSF/3 wt% ZSM‐5 retained 65% of its original IC in an alkaline medium after 7 days. QPSF/3 wt% ZSM‐5 exhibited a stable discharge voltage of 1.3 V and a specific capacity of 11,716 mAh/g_Al in a laboratory fabricated Al‐air cell. This study provides an excellent anion exchange composite membrane separator candidate for Al‐air battery applications.