Novel hydroxide ion-conductive composite membranes were fabricated through incorporating coprecipitation-synthesized magnesium (Mg)–aluminum (Al)-type layered double hydroxides (LDHs) into a potassium hydroxide (KOH)-doped polybenzimidazole (PBI) membrane to improve the hydroxide ion conductivity for the application to alkali fuel cells. The addition of LDH was essential for improving the water affinity of the PBI–KOH membranes. Although the KOH uptake of the LDH-incorporated PBI membranes decreased with increasing amounts of LDHs in the water uptake test, thermal analysis showed that the water content in the membrane increased with increasing amounts of added LDHs. LDH-incorporated PBI membranes showed the high hydroxide ion conductivity and the reduced dependent of the humidity because of the high amount of adsorbed water and high ionic conductivity of LDHs. The alkaline fuel cell performance evaluation test showed that the prepared PBI–KOH membrane with 30 wt% LDH had the highest power output, exhibiting a maximum power density of 210 mW cm⁻¹ at 80 °C, which is more than double that of the cell device without LDH. Improved performance due to the high-water adsorption and hydroxide ion conductivity was achieved by incorporating LDHs into the KOH-doped PBI membranes.

通过将共沉淀法合成的镁 (Mg)-铝 (Al) 型层状双氢氧化物 (LDHs) 掺入氢氧化钾 (KOH) 掺杂的聚苯并咪唑 (PBI) 膜中以提高氢氧根离子传导性，制备了新型氢氧根离子导电复合膜。用于碱性燃料电池的电导率。添加 LDH 对于提高 PBI-KOH 膜的亲水性至关重要。尽管在吸水试验中加入 LDH 的 PBI 膜的 KOH 吸收随着 LDH 量的增加而降低，但热分析表明膜中的水含量随着加入的 LDH 量的增加而增加。由于 LDH 的大量吸附水和高离子电导率，掺入 LDH 的 PBI 膜显示出高氢氧根离子电导率和降低的湿度依赖性。碱性燃料电池性能评估测试表明，制备的具有 30 wt% LDH 的 PBI-KOH 膜具有最高的功率输出，最大功率密度为 210 mW cm^-1在 80 °C，这是没有 LDH 的电池设备的两倍多。通过将 LDH 掺入 KOH 掺杂的 PBI 膜中，实现了由于高水吸附和氢氧根离子电导率而提高的性能。