Construction of Quaternized Polysulfone/Polyquaternium‐10 Anion Exchange Membrane with Semi‐Interpenetrating Network for Alkaline Fuel Cell

Abstract

The quaternized polysulfone/polyquaternium-10 (QPSU/PQ-10) anion exchange membranes (AEMs) with a semi-interpenetrating network are prepared by the simple solution casting method. The effects of the mass ratio of chloromethylated polysulfone (CMPSU) to PQ-10 and the molar ratio of quaternized chloromethyl (QCM) to cross-linked chloromethyl (CCM) on the performance of AEM are systematically investigated. The results show that the introduction of PQ-10 endows the QPSU/PQ-10 AEM with excellent mechanical performance. More specifically, the QPSU/PQ-10 AEM has moderate water uptake, swelling ratio, and ion exchange capacity (IEC) at an appropriate composition ratio and crosslinking degree. In particular, the tensile strength and elongation at break of the QP0.5-1 membrane with the optimal composition ratio and crosslinking degree are 23.63 MPa and 20.07%, respectively; and its ion conductivity is up to 69.91 mS cm −1 at 80 °C. Furthermore, the peak power density of the single fuel cell assembled from the QP0.5-1 membrane is 75.64 mW cm −2 at 60 °C. Herein, the QPSU/PQ-10 AEM has good thermal oxidation stability, mechanical properties, and ion conductivity, highlighting the potential of bio-based PQ-10 as an ion-conducting functional molecule in AEMs.

Tripartite Cationic Interpenetrating Polymer Network Anion Exchange Membranes for Fuel Cells

“…The mass loss at 300–370 °C is assigned to the degradation of polymer skeleton (QPSVBC and PQ 10 ). The DTG curve of un-crosslinked PQ 10 should have a decomposition peak of molecular backbone at around 350 °C. , However, because the crosslinking reaction between PQ 10 and epichlorohydrin promotes the intermolecular interaction in the membranes, the decomposition temperature of its molecular chain increases to a similar level to that of the QPSVBC molecular chain. Meanwhile, compared with CQV 50% AEM (Figure S5), the decomposition temperature of the QPSVBC molecular chain in QVP x – y AEMs also slightly increases under the influence of F-IPN structure, and the decomposition peaks of the two molecular chains merge together (around 370 °C), which also indicates from the side that an F-IPN structure is indeed formed in the membranes.…”

“…Nonetheless, a high IEC value means that the membrane will absorb a large amount of water and swell rapidly with the sacrifice of mechanical, dimensional, as well as chemical stability of the membrane. − Normally, the strategy of constructing semi- or fully interpenetrating polymer networks inside the membrane by crosslinking can effectively enhance molecular interactions, which is effective in reducing water molecules from entering the membrane at high IEC values. − Besides the contradiction between high IEC value and high ionic conductivity, another major problem faced by AEMs is insufficient alkali stability. Typical AEMs composed of polysulfone (PSU), poly­(phenylene oxide) (PPO), and polyether ketone (PEK) always suffer from the notorious chain degradation under extreme pH conditions, − in which high concentration of OH – tends to destroy the aryl ether (C–O) bonds within those polymers, damaging the long-term stability of AEMs. − Other polymers without introducing C–O bonds, such as polystyrene (PS), poly­(ethylene- co -octene)- b -polystyrene (SEBS), etc., have been employed as the framework of AEMs to increase their stability at high temperatures and high pH values. , As an example, Sung et al prepared a series of AEMs with SEBS as backbone, among which the AEM with a preferred crosslinking degree exhibited excellent alkaline stability after storage in 1 M KOH solution at a constant temperature of 80 °C for 500 h …”

Quaternized Branched Polyethyleneimine Modified Nitrogen‐Doped Graphene Quantum Dots/Quaternized Polysulfone Composite Anion Exchange Membranes with Improved Performance

“…According to the experimental method of the previous work, [41] QPSU was synthesized by chloromethylation and quaternization of polysulfone. Briefly, in a three-necked flask, 5 g of polysulfone was dissolved in 500 mL of chloroform, wherein 6.7 g of 1,3,5trioxane, 0.26 mL of SnCl 4 , and 28.5 mL of trimethylchlorosilane were added and allowed to mix thoroughly for 3 h. The above three-necked flask containing the reactants was placed in an oil bath at 55 °C for 3 days.…”

Semi-Interpenetrating Network Anion Exchange Membranes by Thiol–Ene Coupling Reaction for Alkaline Fuel Cells and Water Electrolyzers

“…The essential component of AEMFCs and AEMWE is the anion exchange membrane (AEM), which is designed for separating the cathode and anode of the battery, and it is crucial for ion transport [ 11 ]. It directly determines the performance of AEMFCs, including service life and power density [ 12 ]. Nevertheless, the need to strike a balance between the mechanical properties and ionic conductivity of AEMs presents an urgent challenge.…”

“…The two polymers in this network can function independently, allowing the AEM to possess both efficient ion transport properties and excellent mechanical properties. Additionally, the semi-interpenetrating structure of the network prevents excessive swelling of the membrane, ultimately allowing efficient ion conduction under a comparatively low IEC [ 12 ].…”