Polybenzimidazole Confined in Semi-Interpenetrating Networks of Crosslinked Poly (Arylene Ether Ketone) for High Temperature Proton Exchange Membrane

Abstract

As a traditional high-temperature proton exchange membrane (HT-PEM), phosphoric acid (PA)-doped polybenzimidazole (PBI) is often subject to severe mechanical strength deterioration owing to the “plasticizing effect” of a large amount of PA. In order to address this issue, we fabricated the HT-PEMs with a crosslinked network of poly (arylene ether ketone) to confine polybenzimidazole in semi-interpenetration network using self-synthesized amino-terminated PBI (PBI-4NH2) as a crosslinker. Compared with the pristine linear poly [2,2′-(p-oxdiphenylene)-5,5′-benzimidazole] (OPBI) membrane, the designed HT-PEMs (semi-IPN/xPBI), in the semi-IPN means that the membranes with a semi-interpenetration structure and x represent the combined weight percentage of PBI-4NH2 and OPBI. In addition, they also demonstrate an enhanced anti-oxidative stability and superior mechanical properties without the sacrifice of conductivity. The semi-IPN/70PBI exhibits a higher proton conductivity than OPBI at temperatures ranging from 80 to 180 °C. The HT-PEMFC with semi-IPN/70PBI exhibits excellent H2/O2 single cell performance with a power density of 660 mW cm−2 at 160 °C with flow rates of 250 and 500 mL min−1 for dry H2 and O2 at a backpressure of 0.03 MPa, which is 18% higher than that of OPBI (561 mW cm−2) under the same test conditions. The results indicate that the introduction of PBI containing crosslinked networks is a promising approach to improve the comprehensive performance of HT-PEMs.

Poly(4-vinylpyridine) Based Semi-Interpenetrating Cross-Linked High Temperature Proton Exchange Membranes for Fuel Cells

“…The tensile strength of the PA-doped Semi-IPN 1.0/0.5OPBI membrane was 9.7 MPa, while its elongation was about 23% . The PA-doped Semi-IPN 70PBI membrane showed the tensile strength and elongation of 11.8 MPa and 20.3%, respectively …”

“…31 The PA-doped Semi-IPN 70PBI membrane showed the tensile strength and elongation of 11.8 MPa and 20.3%, respectively. 34 One of the most vital parameters in the utilization of membranes in HT-PEMFC is proton conductivity. 6,10 The anhydrous conductivities of PP and x%CL-PP membranes after doping PA are shown in Figure 8b.…”

“…The 92%PEI–PEKcardo/304%PA membrane showed conductivity as high as 107 mS cm –1 at 180 °C without extra humidification and mechanical strength of 4.6 MPa at 25 °C. Additionally, constructing the semi-interpenetrating (Semi-IPN) network has been demonstrated as a useful method to improve the dimensional and mechanical stabilities for different types of electrolyte membranes. − The Semi-IPN network is normally obtained by dispersing a linear polymer in a covalently cross-linked polymer system. For instance, Gan et al and Zeng et al separately prepared PVP and sulfonic poly­(ether ether ketone) (sPEEK) based Semi-IPN membranes for vanadium flow battery applications.…”

Composite membranes consisting of acidic carboxyl-containing polyimide and basic polybenzimidazole for high-temperature proton exchange membrane fuel cells

“…The data show that the oxidative stability of PA-doped membranes is the result of the combined effect of PA adsorption and mechanical properties, which is also consistent with our previous research. 48…”

Achieving 1060 mW cm−2 with 0.6 mg cm−2 Pt Loading Based on Imidazole‐Riched Semi‐Interpenetrating Proton Exchange Membrane at High‐Temperature Fuel Cells

“…[41,42] However, to the best of our knowledge, research on HT-PEM employing sIPN structure is limited. [43][44][45] Huang et al demonstrated poly(vinyl alcohol)/polyacry-lamide sIPN PEM with excellent PA retention. [43] Wang and Meng fabricated HT-PEMs with a crosslinked network of poly (arylene ether ketone) to confine PBI in a sIPN structure, thereby improving the mechanical strength.…”