Jump to main content
Jump to site search


Identification of stoichiometric and microstructural parameters of a lithium-ion cell with blend electrode

Abstract

The measurement of the active material volume fraction in composite electrodes of lithium-ion battery cells is difficult due to the small (sub-micrometer) and irregular structure and multi-component composition of the electrodes, particularly in the case of blend electrodes. State-of-the-art experimental methods such as focused ion beam/scanning electron microscopy (FIB/SEM) and subsequent image analysis require expensive equipment and significant expertise. We present here a simple method for identifying active material volume fractions in single-material and blend electrodes, based on the comparison of experimental equilibrium cell voltage curve (open-circuit voltage as function of charge throughput) with active material half-cell potential curves (half-cell potential as function of lithium stoichiometry). The method requires only (i) low-current cycling data of full cells, (ii) cell opening for measurement of electrode thickness and active electrode area, and (iii) literature half-cell potentials of the active materials. Mathematical optimization is used to identify volume fractions and lithium stoichiometry ranges in which the active materials are cycled. The method is particularly useful for model parameterization of either physicochemical (e.g., pseudo-two-dimensional) models or equivalent circuit models, as it yields a self-consistent set of stoichiometric and structural parameters. The method is demonstrated using a commercial LCO-NCA/graphite pouch cell with blend cathode, but can also be applied to other blends (e.g., graphite-silicon anode).

Back to tab navigation

Publication details

The article was received on 31 Jul 2019, accepted on 10 Oct 2019 and first published on 10 Oct 2019


Article type: Paper
DOI: 10.1039/C9CP04262H
Phys. Chem. Chem. Phys., 2019, Accepted Manuscript

  •   Request permissions

    Identification of stoichiometric and microstructural parameters of a lithium-ion cell with blend electrode

    M. Mayur, M. C. Yagci, S. Carelli, P. Margulies, D. Velten and W. G. Bessler, Phys. Chem. Chem. Phys., 2019, Accepted Manuscript , DOI: 10.1039/C9CP04262H

Search articles by author

Spotlight

Advertisements