Computer simulations of the impedance response of lithium rechargeable batteries

• Published in: Journal of the Electrochemical Society Vol. 147; no. 1; pp. 99 - 110
• Main Authors: DOYLE, M, MEYERS, J. P, NEWMAN, J
• Format: Journal Article
• Language: English
• Published: Pennington, NJ Electrochemical Society 2000
• Subjects: Applied sciences; COMPUTERIZED SIMULATION; Direct energy conversion and energy accumulation; ELECTRIC IMPEDANCE; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; ENERGY STORAGE; Exact sciences and technology; LITHIUM; MATHEMATICAL MODELS; METAL-NONMETAL BATTERIES; Transport process; Electrode impedance; Computer simulation; Polymer solid electrolyte; Theoretical study; Secondary cell; Solid electrolyte storage battery; Diffusion coefficient; Mathematical model; Physicochemical properties; Lithium sulfur batteries; Electrochemical characteristic
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1.1393162

A mathematical model is developed to simulate the impedance response of a wide range of lithium rechargeable battery systems. The mathematical model is a macroscopic model of a full-cell sandwich utilizing porous electrode theory to treat the electrode region and concentrated solution theory for transport processes in solution. Insertion processes are described with charge-transfer kinetic expressions and solid-phase diffusion of lithium into the active electrode material. The impedance model assumes steady-state conditions and a linear response with the perturbation applied about the open-circuit condition for the battery. The simulated impedance response of a specific system, the lithium-polymer cell Li{vert{underscore}bar}PEO{sub 18}LiCF{sub 3}So{sub 3}{vert{underscore}bar}LiTiS{sub 2}, is analyzed in more detail to illustrate several features of the impedance behavior. Particular attention is paid to the measurement of solid-phase lithium-ion diffusion coefficients in the insertion electrodes using impedance techniques. A number of complications that can lead to errors in diffusion-coefficient measurements based on impedance techniques are discussed.