Thin solid state reference electrodes for use in solid polymer electrolytes

Abstract

This paper reports two low-profile (~10μm thick) solid state reference electrodes for use in solid polymer electrolytes. The thin, open geometry of the electrodes enables close positioning between the working and counter electrodes. The first electrode uses the palladium hydride (Pd|PdHx) couple (PHRE), and the second utilises the hydrous iridium oxide (IrOx·yH2O|IrOa·bH2O) couple (IORE). To our knowledge this is the first use of the latter as a reference electrode. The PHRE had a stable potential of +70mV vs RHE with a 4mVh−1 drift and two hour lifetime, whilst the IORE gave a potential of +847mV vs RHE with a drift of 0.3mVh−1 and no deterioration after 24h of use. The use of these reference electrodes in a three-electrode solid state cell and a fuel cell is demonstrated.