Determination of state of charge-dependent asymmetric Butler-Volmer kinetics for LixCoO2 electrode using GITT measurements

Hess A, Roode-Gutzmer Q, Heubner C, Schneider M, Michaelis A, Bobeth M, Cuniberti G (2015)

Publication Type: Journal article

Publication year: 2015

Journal

Journal of Power Sources Elsevier

Book Volume: 299

Pages Range: 156-161

DOI: 10.1016/j.jpowsour.2015.07.080

Abstract

GITT (Galvanostatic Intermittent Titration Technique) measurements of LixCoO2/Li half-cell voltages were numerically simulated based on Newman's well established electrochemical pseudo 2D model. The measurements revealed differences in the charge transfer kinetics between charging and discharging, which change with the state of charge of LixCoO2. To properly account for these differences in the simulations, SOC-dependent reaction-rate constant together with SOC-dependent charge transfer coefficients were introduced, which were unambiguously determined from the measured IR drops of the GITT pulses during charging and discharging. Furthermore, the SOC-dependence of the chemical Li-ion diffusion coefficient in LixCoO2 was analyzed by fitting the GITT data within the framework of the pseudo 2D model, as well as by means of classical analysis by Weppner and Huggins [W. Weppner and R. A. Huggins, J. Electrochem. Soc. 124 (1977) 1569]. Improvement of the simulation of GITT measurements using SOC-dependent rate constants and charge transfer coefficients compared to SOC-independent values is demonstrated.

Involved external institutions

Technische Universität Dresden DE Germany (DE) Fraunhofer-Institut für Keramische Technologien und Systeme (IKTS) DE Germany (DE)

How to cite

APA:

Hess, A., Roode-Gutzmer, Q., Heubner, C., Schneider, M., Michaelis, A., Bobeth, M., & Cuniberti, G. (2015). Determination of state of charge-dependent asymmetric Butler-Volmer kinetics for LixCoO2 electrode using GITT measurements. Journal of Power Sources, 299, 156-161. https://dx.doi.org/10.1016/j.jpowsour.2015.07.080

MLA:

Hess, Andreas, et al. "Determination of state of charge-dependent asymmetric Butler-Volmer kinetics for LixCoO2 electrode using GITT measurements." Journal of Power Sources 299 (2015): 156-161.

BibTeX: Download