Electric-field-aligned functionalized-layered double hydroxide/polyphenyl ether composite membrane for ion transport. (21st May 2019)

• Record Type: Journal Article
• Authors: Wang, Dong; Chen, Nanjun; Long, Chuan; Lu, Chuanrui; Li, Yunxi; Zhu, Hong; Wang, Fanghui
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 26(2019)
• Page Start: 13852
• Page End: 13863
• Publication Date: 2019-05-21
• Subjects: Hydroxide exchange membrane -- Ion conductivity -- Electric-field orientation -- Fuel cells; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.03.252
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: To address the insufficient ion conductivity of hydroxide exchange membranes (HEMs) used in alkali membrane fuel cells (AMFCs), we present a series of aligned layered double hydroxide (LDH)/polyphenyl ether (PPO) composite membranes based on the electrorheological effect. The hexagonal LDH was functionalized with N-spirocyclic ammonium (ASU-LDH) to enhance the electrorheological effect of the ASU-LDH as well as improve the ion conductivity of the ASU-LDH. The aligned ASU-LDH/triple-cation-functionalized PPO (ASU-LDH/TC-PPO) composite membranes were prepared by applied-electric field. The effective electric-induced ion channels (EICs) were constructed by aligned ASU-LDH nanosheets in HEMs, which are distinctly observed by scanning electron microscope (SEM). Notably, these EICs-contained ASU-LDH/TC-PPO composite membranes exhibit the higher ion conductivity and alkaline stability than those of normal TC-PPO and ASU-LDH/TC-PPO membranes. It is worth noticing that these EICs are different with the traditional phase-induced ion channels, the EICs show the shorter ion transport distances and broader water channels in HEMs. Attributing to EICs, the longitudinal ion conductivity of aligned ASU-LDH/TC-PPO membrane shows 32.2% and 18.7% improvement compared to pristine TC-PPO and normal ASU-LDH/TC-PPO membrane. The maximum ion conductivity of the aligned ASU-LDH/TC-PPO composite membrane reaches to 109.8 mS/cm at 80 °C. The long-term stability test shows that the aligned ASU-LDH/TC-PPO membranes still exhibit enhancing alkali resistance (83.2%) in 1 M KOH at 80 °C for 500 h. In brief, this work provides a novel and effective approach to prepare high-performance HEMs. Graphical abstract: Image 1 Highlights: Electric-induced ion channels (EICs) were constructed by aligning ASU-LDH. The EICs is built using an electric field method. Electric-induced ion channels were effectively constructed and clearly observed. The EICs show the shorter ion transport distances and broader water channels. The composite membrane shows higher ion conductivity and chemical stability.