Cellulose nanocrystal-based composite electrolyte with superior dimensional stability for alkaline fuel cell membranes

Journal Article · Wed May 13 00:00:00 EDT 2015 · Journal of Materials Chemistry. A

DOI:https://doi.org/10.1039/C5TA02304A· OSTI ID:1215579

Lu, Yuan ^[1]; Artmentrout, Aaron A. ^[1]; Li, Juchuan ^[1]; Tekinalp, Halil L. ^[1]; Nanda, Jagjit ^[1]; Ozcan, Soydan ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division

Cellulose nanocrystal (CNC)-based composite films were prepared as a solid electrolyte for alkaline fuel cells. Poly (vinyl alcohol) (PVA) and silica gel hybrid was used to bind the CNCs to form a robust composite film. The mass ratio (i.e., 1 : 1, 1 : 2) of PVA and silica gel was tuned to control the hydrophobicity of the resulting films. Composite films with a range of CNC content (i.e., 20 to 60%) were prepared to demonstrate the impact of CNC on the performance of these materials as a solid electrolyte for alkaline fuel cells. Different from previously reported cross-linked polymer films, CNC-based composite films with 40% hydrophobic binder (i.e., PVA : silica gel=1 : 2) exhibited simultaneous low water swelling (e.g., ~5%) and high water uptake (e.g., ~80%) due to the hydrophilicity and extraordinary dimensional stability of CNC. It also showed a conductivity of 0.044 and 0.065 S/cm at 20 and 60 oC, respectively. To the best of our knowledge, the film with 60% CNC and 40% binder is characterized by the lowest hydroxide conductivity-normalized swelling ratio. Decreased CNC content (i.e., 40 and 20%) resulted in comparable hydroxide conductivity but a greater swelling ratio. Finally, these results demonstrate the advantage of CNC as a key component for a solid electrolyte for alkaline fuel cells over conventional polymers, suggesting the great potential of CNCs in improving the dimensional stability while maintaining the conductivity of existing anion exchange membranes.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1215579
• Journal Information: Journal of Materials Chemistry. A, Vol. 3, Issue 25; ISSN 2050-7488
• Publisher: Royal Society of Chemistry
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY