Through a continuous recording of the cell voltage, heat flow, and current, the effective thermoneutral potential, Eetpof Li/BCX and Li/SOCl2 cells were determined in the temperature range, 0–60°C. The depth of discharge (DOD), temperature (T), and cell type (cell chemistry) affect the effective thermoneutral potential. The effective thermoneutral potential, Eetp differs from the classical thermoneutral potential of a cell because it takes into account the heat flow due to non-faradaic processes. The average effective thermoneutral potential at 25°C (determined by selecting the most constant region of Eetp vs. time of discharge) was 4.0 and 3.84 V for BCX and Li/SOCl2 cells, respectively. Based on the classical approach, the reversible cell potential, Er and temperature dependence of reversible cell potential, dEr/dT for BCX cell were 3.74 V and –0.852 mV/K, respectively, and for Li/SOCl2, Er = 3.67 V and dEr/dT = –0.567 mV/K. The thermal polarization (Eetp – El), where El, is the load voltage, for both cells, showed that they are most thermally efficient near 40°C. A measure of the heat flow for both cells at 50% DOD supports this observation. An overall reaction proposed for the BCX chemistry is supported by the calculated thermodynamic parameters.
Journal of the Electrochemical Society, 1992, pages 2755-2759.
© The Electrochemical Society, Inc. 1992. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in the Journal of the Electrochemical Society.