Investigation of the electrode/electrolyte interface for the Cu + ion solid electrolyte N,N′-dimethyl-triethylene diamine-copper(1) bromide

Abstract

The Cu + ion solid electrolyte 47Cu Br·3(CH 3) 2 C 6H 12N 2Br 2 was prepared by hot-pressing and characterised by X-ray analysis and electrical measurements. Novel cell arrangements were used to study the electrochemical behaviour of interfaces between this electrolyte and copper metal and also between this electrolyte and two well known solid solution electrodes (SSEs) for copper, Cu 2Mo 6S 7.59 and Cu 1.8S. The behaviour of the electrolyte/copper interface was correlated with scanning electron microscope (SEM) examinations showing the growth of copper dendrites at the interface. Results from the electrolyte/SSE interfaces showed that there is no interfacial polarisation and that the electrode polarisation is controlled solely by the diffusion of Cu + ions in the SSE. These experiments allowed estimates of the chemical diffusion coefficient for Cu + ions in each material to be made.