To improve the performance and durability of phosphoric acid (PA) doped polybenzimidazole (PBI) membranes in high–temperature proton exchange membrane fuel cells (HT–PEMFCs), in this work, as–received natural muscovite (Mus), a clay material, was successfully incorporated into PBI matrix as an inorganic filler through the doctor blade method. The amount of Mus was varied (0.5–2 wt%) to explore its impact on the proton conductivity, mechanical and dimensional stability, power density, durability, and acid retention ability of the composite membranes. As the incorporation of Mus into membranes can introduce interactions with polymer chains and PA molecules to afford additional proton transport pathways at the interfaces in Mus–PBI and Mus–PA crosslinks, the membrane with 1 wt% Mus showed highest power density of 586 mW cm⁻² at 150 °C without humidification, 24% higher than the pure PBI membrane (474 mW cm⁻²). Meanwhile, the PA doped composite membrane with 1 wt% Mus also displayed the highest mechanical strength (7.5 MPa) and lowest dimensional swelling (70.99% in area swelling and 202% in volume swelling). Compared with the pristine PBI membrane, the composite membranes had significantly improved durability under accelerated stress test (AST). The decreased ohmic resistance and increased polarization resistance after AST are related to the membrane thinning and the loss of catalyst active area, respectively. Most importantly, it was found that the strong interactions between Mus and PA molecules lead to improved acid retention ability of the composite membranes, thus less leached acid from the composite membrane reduces the negative effects on the catalyst degradation to alleviate degradation on cell performance and durability.

为了提高磷酸 (PA) 掺杂的聚苯并咪唑 (PBI) 膜在高温质子交换膜燃料电池 (HT-PEMFCs) 中的性能和耐久性，在这项工作中，作为接收的天然白云母 (Mus)，一种粘土材料，通过刮刀法成功地将其作为无机填料掺入 PBI 基体中。改变 Mus 的量 (0.5-2 wt%) 以探索其对复合膜的质子电导率、机械和尺寸稳定性、功率密度、耐久性和酸保留能力的影响。由于将 Mus 掺入膜中可以引入与聚合物链和 PA 分子的相互作用，从而在 Mus-PBI 和 Mus-PA 交联的界面处提供额外的质子传输途径，因此含有 1 wt% Mus 的膜显示出最高的功率密度为 586 mW cm ⁻²在 150 °C 下不加湿，比纯 PBI 膜（474 mW cm ^-2）。同时，含有 1 wt% Mus 的 PA 掺杂复合膜也表现出最高的机械强度（7.5 MPa）和最低的尺寸膨胀（面积膨胀 70.99% 和体积膨胀 202%）。与原始 PBI 膜相比，复合膜在加速应力测试 (AST) 下的耐久性显着提高。AST 后欧姆电阻的降低和极化电阻的增加分别与膜变薄和催化剂活性面积的损失有关。最重要的是，发现 Mus 和 PA 分子之间的强相互作用导致复合膜的酸保留能力提高，因此从复合膜中浸出的酸减少了对催化剂降解的负面影响，从而减轻了对电池性能和耐久性的降低.