Mathematical Modeling of the Lithium‐Aluminum, Iron Sulfide Battery: I . Galvanostatic Discharge Behavior

A mathematical model of the LiA1/LiC1, KC1/FeS high temperature bat-tery is presented. The model considers a whole prismatic cell which consists of negative electrode, separator, electrolyte reservoir, and positive electrode. Physical phenomena described are ohmic potential drop and diffusion potential in the electrolyte, changes in porosity and electrolyte composition due to elec-trochemical reactions, local reaction rates, and diffusion, convection, and mi-grat ion of electrolyte. In addition, the analysis includes finite matr ix conduc-tivities, var iable physical properties, and the possibi l ity of specific s imul-taneous reactions in the positive electrode. The theoretical results show many of the trends in behavior observed experimental ly. The effects of state of charge, init ial electrolyte composition, cell temperature, and current density are presented, and factors that can l imit cell performance are identified. The LiA1/LiC1, KC1/FeSx high temperature battery is a candidate for off-peak electrical energy storage