Synthesis of an Alkaline-Stable In Situ Cross-Linked Poly(ether imide)-Based Anion Exchange Membrane Electrolyte for Water Electrolyzers and Fuel Cell Applications
Iyappan Arunkumar, Md. Masud Rana, A. Jeevitha, Ramasamy Gokulapriyan, Jae Hyeon Yu, Dong Jin Yoo
Abstract
Poly(ether imide) (PEI) is a low-cost, easy-to-synthesize anion exchange membrane (AEM) used in energy applications. However, PEI-based AEMs are not highly investigated for anion exchange membrane fuel cells (AEMFCs) and water electrolyzers (AEMWEs) due to their alkaline-susceptible polymer backbone. In this study, a series of cross-linked poly(ether imide)–poly(triphenyl benzene piperidinium) (PEI–PTP- x, x = wt % of PTP) AEMs were prepared for AEMFCs and AEMWEs. Notably, the PEI–PTP-60 membrane reached a maximum hydroxide conductivity of 82.16 mS cm –1, whereas the pristine PEI membrane reached 35.13 mS cm –1 at 90 °C. In a H 2 /O 2 AEMFC test, the PEI–PTP-60 membrane demonstrated the highest peak power density (PPD) of 210.17 mW cm –2 with a current density of 707.12 mA cm –2, whereas the pristine PEI membrane reached a PPD of 156.62 mW cm –2 with a current density of 506.81 mA cm –2 . In AEMWEs, PEI shows a current density of 825 mA cm –2 and 1515 mA cm –2 at 1.8 and 2.0 V, respectively, whereas PEI–PTP-60 shows a current density of 875 mA cm –2 and 1562.5 mA cm –2 at 1.8 and 2.0 V, respectively. These results demonstrate a reliable approach to improve the physicochemical and electrochemical characteristics of the poly(ether imide) AEM electrolyte for use in AEMWEs and AEMFCs.