Ionic conductivity enhancement in PEO:CuSCN solid polymer electrolyte by the incorporation of nickel-chloride

Journal article, 2015

© 2015 Elsevier B.V. All rights reserved. Copper-ion based solid polymer electrolytes exhibit interesting electrochemical properties, environmental stability and lower fabrication cost compared to lithium ion based systems. Although, poly(ethylene oxide)(PEO)-based solid polymer electrolytes have been extensively studied, those incorporating copper salts have not been explored much. One major drawback in these electrolytes is the low ionic conductivity at room temperature. In this work, we attempted to enhance the ionic conductivity of PEO 9 CuSCN polymer electrolyte by the incorporation of NiCl 2 . Incorporation of 10 wt% NiCl 2 showed the highest conductivity enhancement with almost two orders of magnitude increase. The ionic conductivity value at 30 °C increased from 3.1 × 10- 9 S cm- 1 for the NiCl 2 -free electrolyte to 1.8 × 10- 7 S cm- 1 for the 10 wt% NiCl 2 incorporated electrolyte. This was associated with a significant reduction in T g by about 30 °C from - 53 °C for PEO 9 CuSCN to - 83 °C for PEO 9 CuSCN + 10 wt% NiCl 2 , indicating an increased segmental flexibility of the polymer chains for NiCl 2 added electrolyte.