화학공학소재연구정보센터
Applied Energy, Vol.99, 291-296, 2012
A study of the Ce3+/Ce4+ redox couple in sulfamic acid for redox battery application
The present paper reports a cerium sulfamate electrolyte for use in redox battery. The electrochemical behavior of Ce3+/Ce4+ in sulfamic acid (SA) media has been investigated using linear-sweep voltammetry and cyclic voltammetry. The formal potential of the Ce3+/Ce4+ redox couple in SA is approximately 1.52 V vs. NHE. The exchange current density and standard rate constant of the Ce3+/Ce4+ redox reaction on platinum electrode in SA are determined as 5.95 x 10(-4) A cm(-2) and 4.95 x 10(-5) cm s(-1) respectively. The diffusion coefficient of Ce3+ in SA is 5.93 x 10(-6) cm(2) s(-1). The conductivity of cerium(III) sulfamate solution is improved significantly by adding NH4+. A zinc-cerium test cell with Ce3+/Ce4+ sulfamate solution as the positive electrolyte is constructed and the charge-discharge performance is evaluated. The coulombic efficiency of the Zn-Ce cell is calculated to be 90%. The preliminary exploration shows that the cerium sulfamate electrolyte is promising for redox battery application and is worthy of further study. (C) 2012 Elsevier Ltd. All rights reserved.