Metallo-Polyelectrolyte-Based Robust Anion Exchange Membranes via Acetalation of a Commodity Polymer

Abstract

Metallo-polyelectrolytes have been demonstrated to be promising candidates for anion exchange membranes (AEMs) due to their excellent alkaline stability. Here, cobaltoceniumcontaining metallo-polyelectrolyte-based AEMs with good chemical stability and dimensional stability were prepared through facile acetalation of a commodity polymer, poly(vinyl alcohol). The AEM crosslinked with 1 wt % glutaraldehyde (GA) exhibits a comparable hydroxide conductivity of 72 mS/cm at 80 °C and enhanced alkaline stability in 1 M NaOH at 80 °C (maintained 86.3% of initial hydroxide conductivity after 1000 h). The dimensional stability of these AEMs can be tuned through acetalation crosslinking with GA, and the swelling ratio of 1% GA was 17.8% and the gel fraction was 90.5%. The H 2 /O 2 single cell using 1% GA AEM (50 μm, Fumion ionomer) showed a maximum power density of 120 mW/cm 2 at 60 °C without backpressure. This work provides a facile method for the preparation of stable metallo-polyelectrolyte-based alkaline membrane fuel cells.

Role of Ionic Concentration and Distribution in Anionic Conductivity: Case Study on a Series of Cobaltocenium-Containing Anion Exchange Membranes with Precise Structure Control

“…1 H NMR (400 MHz, DMSO-d 6 , δ, ppm): 1.56 (m, 2H), 1.98 (t, 2H, J = 5.6 Hz), 2.13 (q, 1H, J = 4.8 Hz), 2.79 (s, 2H), 4.80 (q, 2H, J = 11.2 Hz), 4.99 (d, 4H, J = 13.2 Hz), 5.33 (m, 1H), 5.65 (s, 10H), 5.97 (t, 4H, J = 2.0 Hz), 6.08 (q, 1H, J = 3.2 Hz), 6.13 (q, 1H, J = 2.8 Hz), 6.40 (t, 4H, J = 2.0 Hz), 8.73 (d, 2H, J = 8.0 Hz). 19 The characterization of membrane structure, ion exchange capacity, and ionic conductivity was consistent with our previous report, 49 which is illustrated in the Supporting Information.…”

“…The chloride conductivity of P2-18Co AEM decreased compared with P2 under a given IEC, which may result from the dispersed ion clusters by the introduction of unfunctionalized norbornene . In addition, all of these AEMs showed an Arrhenius behavior between 30 and 80 °C (Figure B), and the corresponding activation energy of E a was 22.1, 20.4, and 21.8 kJ mol –1 for P1 , P2 , and P3 , respectively, where the E a value was close to those of previous cobaltocenium-containing AEMs. , These results indicated that P2 -based AEM had the highest chloride conduction efficiency, and Cl – in P2 can transport with less activation energy compared with the other two membranes …”

“…67 In addition, all of these AEMs showed an Arrhenius behavior between 30 and 80 °C (Figure 5B), and the corresponding activation energy of E a was 22.1, 20.4, and 21.8 kJ mol −1 for P1, P2, and P3, respectively, where the E a value was close to those of previous cobaltocenium-containing AEMs. 49,52 These results indicated that P2-based AEM had the highest chloride conduction efficiency, and Cl − in P2 can transport with less activation energy compared with the other two membranes. 68 In principle, the well-defined ionic channels derived from microphase separation are beneficial to high ionic conductivity.…”

“…The resulting membranes were soaked in 4 M NH 4 Cl aqueous solution at 60 °C for 72 h to obtain the corresponding membranes in Cl – form. The characterization of membrane structure, ion exchange capacity, and ionic conductivity was consistent with our previous report, which is illustrated in the Supporting Information.…”

Synthesis of Proton Conductive Copolymers of Inorganic Polyacid Cluster Polyelectrolytes and PEO Bottlebrush Polymers

“…A landmark solid electrolyte, Nafion, possesses a macromolecular structure with a hydrophobic backbone and a hydrophilic side chain containing sulfonic groups, which can form continuous proton-conducting pathways to achieve a high proton conductivity . In contrast to traditional organic polyelectrolytes, metallopolymers containing multiple charged groups make up a class of inorganic hybrid polyelectrolytes. − As previously reported, rational design and careful synthesis can be used to construct useful hybrid polyelectrolytes and optimize their properties and performances for the manufacture of new functional materials …”