Performance improvement of PVA-based alkaline polymer electrolyte membrane using micro-crystalline cellulose as functional filler.

One kind of PVA/PAA-based alkaline solid polyelectrolyte (ASPE) membrane with high conductivity and good mechanical property was prepared via the introduction of the micro-crystalline cellulose (MCC) as functional fillers. An ion conductivity of 95 mS cm⁻¹ with high alkali resistance was achieved when the MCC content reached up to 5wt%, which is 4.5-fold higher than the control. SEM image showed a denser pore structure that is beneficial for the OH⁻ conduction after MCC addition. X-ray diffraction further indicated a gradually decreased crystallinity of KOH with the addition of MCC. This means more content of KOH would exist in the ionic form in the remained water caused by the added MCC in the system. This leads to the increased content of OH⁻ and the resulting ion conductivity. The window equals to 0.9 V and improved mechanical properties were observed after a 5wt% content of MCC was added in the ASPE membrane system. [ABSTRACT FROM AUTHOR]