Temperature effect upon the thermoelectrochemical potential generated between lithium metal and lithium ion intercalation electrodes in symmetric and asymmetric battery arrangements

Abstract

The evaluation of batteries under thermal gradients is essential for safety and longevity reasons, and to investigate power generation via the thermogalvanic effect. The thermogalvanic Seebeck coefficient of lithium metal (+1.0mV·K−1) and solid lithium ferri/ferrocyanide intercalation electrodes (−0.6mV·K−1) were determined. The measured Seebeck coefficients of identical asymmetric cells containing both electrodes deviated from the expected values, having Seebeck coefficients which also varied as a function of thermal conditions (+0.7 to +4.3mV·K−1). This work demonstrates that the thermal responses of asymmetric battery assemblies are more complex than predicted based upon their individual half-cell performances in symmetric cells.