Proton conductivity and chemical stability of Li₂SO₄ based electrolyte in a H₂S–air fuel cell
By Li, Jinxia; Luo, Jing-Li; Chuang, Karl T. & Sanger, Alan R.
Published in Journal of Power Sources
2006
Abstract
Proton conductivity of Li₂SO₄-Al2O3 (LA) based electrolyte was determined under non-reducing dynamic conditions using current interruption technique. The performance of LA as electrolyte has been examined at 600 °C in a H₂S fuel cell with MoS₂-NiS as anode catalyst and NiO as cathode catalyst. XRD and XPS results show that Li₂SO₄ is not stable when heated in pure H₂S as it is reduced to Li₂S by hydrogen produced in equilibrium amounts from the thermal decomposition of H₂S. In contrast, under dynamic operation in a H2S fuel cell the concentration of H₂ is much lower, the reduction reaction does not occur and, surprisingly, Li₂SO₄ is a chemically stable electrolyte.