Hydroxide (OH- ion)-conducting polymer electrolytes are essential for enabling cost effective, solid-state energy storage devices such as electrochemical capacitors (ECs). Ultra-high rate ECs using OH- ion-conducting polymer electrolytes have been developed and characterized. These polymer electrolytes comprised of aqueous tetraethylammonium hydroxide (TEAOH) incorporated into poly(vinyl alcohol) (TEAOH-PVA), poly(ethylene oxide) (TEAOH-PEO), or poly(acrylic acid) (TEAOH-PAA). Solid EC cells enabled by TEAOH-PVA, TEOAH-PEO, and TEAOH-PAA were characterized by electrochemical impedance spectroscopy and cyclic voltammetry under ambient conditions, demonstrating clear differences in performance. Through XRD and DSC analyses, the effects of the polymer hosts on the OH- ion-transport mechanism was revealed. The differences in OH- ion-transport in the polymer electrolytes is likely a result of differences in crystallinity, hydrophilicity, and functional group electronegativity of the polymer hosts. TEAOH-PVA and TEAOH-PAA based solid EC cells achieved an ionic conductivity of 5 mS cm(-1) and an ultra-high rate of 5000 V s(-1) making them suitable for EC applications. Crown Copyright (C) 2016 Published by Elsevier Ltd. All rights reserved.