Fundamentals of classical thermodynamics and chemical species mole balances have been applied to formulate the mathematical equations to compute lithium/air cell reversible reaction voltages, heat transfer rate between the cell and its surroundings, theoretical discharge capacity, and thermal efficiency. The developed formulation also provides a set of mathematical equations to compute the total cathode volume for a desired maximum discharge capacity of a lithium/air cell or battery. (C) 2007 Elsevier B.V. All rights reserved.