Covalent bonding-triggered pore-filled membranes for alkaline fuel cells

Abstract

Highly conductive and physico-chemically stable ion transport channels (ITCs) are desirable for numerous membrane-integrated sustainable technologies such as fuel cells, redox flow batteries, reverse electrodialysis, etc. However, a “trade-off” exists among the ion exchange capacity, conductivity, and stability of the ITCs. In this context, we hereby propose a facile “covalent bonding-triggered (CBT)” strategy for filling of pre-formed membrane pores and formation of CBT-adopted ITCs (CITCs) and high-performance anion exchange membranes (AEMs). The resulting CITCs-integrated AEMs offer high hydroxide conductivity (39.8 mS cm−1 at 30 °C) at low ion-exchange capacity (0.97 mmol g−1) and excellent chemical stability (<6% conductivity loss after being treated in 2 M NaOH aqueous solution at 60 °C for 7 days) due to aligned interfacial reactive sites within the CITCs. Therefore, the fabricated AEMs further exhibit high fuel cell performance, reaching a peak power density of 315 mW cm−2 at 60 °C. Thus, the proposed CBT pore-filling strategy guides the design for the formation of high-performance and durable ITCs, required for fabrication of efficient AEMs.