Lithium sensors based on Li6La3Ta1.5Y0.5O12 and Li6BaLa2Ta2O12 garnet electrolytes for molten lead alloys

Autores/as

Nel-lo, Marc; Ferrer, Òscar; Colominas, Sergi; Abellà, Jordi

Abstract

The development of effective breeding blankets is crucial to the success of future fusion reactors. One of the main liquid breeding candidates is molten eutectic Pb-Li. In this environment, it is essential to control lithium concentration and dosage to keep the adequate composition in the melt. In this frame, on-line and on-board lithium monitoring tools, which can operate under extreme conditions, are required. Electrochemical sensors based on lithium conducting solid electrolytes (Li₆La₃Ta_1.5Y_0.5O₁₂ and Li₆BaLa₂Ta₂O₁₂) were designed and tested. These potentiometric sensors were used to measure the Open Circuit Potential (OCP) in molten lead-lithium alloys with different lithium concentrations. Measurements were performed at 400 °C, 500 °C, and 600 °C. Experimental OCP values were in good agreement with those calculated with the Nernst equation. OCP values showed a linear relationship versus the logarithm of the lithium activities, fulfilling the Nernst equation.