Novel poly(vinyl alcohol)–KOH–H2O alkaline polymer electrolyte

Abstract A series of alkaline thin-film solid electrolytes, based on poly(vinyl alcohol) (PVA), potassium hydroxide (KOH) and water (PVA–KOH–H 2 O) were prepared. Their conductivity was studied using complex impedance method. The most conducting foils were composed of ca. 40 wt.% of PVA, 25–30 wt.% of KOH, and 30–35 wt.% of water. Typical conductivity of such foils reached the level of nearly 10 −3 Ω −1  cm −1 at room temperature. Temperature dependence of the conductivity was found to be in agreement with the Arrhenius expression with the activation energy of the order of 28–22 kJ mol −1 , depending on the electrolytes composition. The electrochemical stability window at the metal/electrolyte interface is of 1.5 V for stainless steel and nickel, and of 1.7 and 2.75 V for platinum and gold, respectively. Such alkaline electrolytes are interesting from the point of view of their potential application in all-solid rechargeable alkaline batteries as well as in small electrochemical devices, such as chemical capacitors, electrochromic or photogalvanic devices.