화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.157, No.7, D417-D421, 2010
Electrochemical Behavior of Graphite in KF-AlF3-Based Melt with Low Cryolite Ratio
The electrochemical behavior of graphite in KF-AlF3-based melt with a cryolite ratio (molar ratio of KF to AlF3) of 1.3 as well as a low oxygen content at 750 degrees C was investigated by cyclic voltammetry, potentiostatic electrolysis, sampled-current voltammetry, and chronopotentiometry. Aluminum deposited on graphite at a potential of ca. 0.25 V (vs Al) and the electrochemical intercalation of potassium into graphite occurred at ca. -0.1 V (vs Al). The intercalation of potassium into graphite enhanced the formation of Al4C3. The deposition of aluminum on graphite was a linear diffusion-controlled process, while its reverse reaction involved kinetic limitations. Sampled-current voltammetry results indicated that the aluminum deposition on graphite was depressed in the potential region extending from about 0.1 to 0.03 V (vs Al). Chronopotentiometry results revealed that the critical cathodic current density for potassium intercalation was about 400 mA cm(-2). (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3430077] All rights reserved.