Published November 26, 2024 | Submitted v1
Working Paper Open

Transport characterization of solid-state Li2FeS2 cathodes from a porous electrode theory perspective

  • 1. ROR icon University of Münster
  • 2. ROR icon University of Bayreuth
  • 3. ROR icon Forschungszentrum Jülich
  • 4. ROR icon California Institute of Technology

Abstract

The abundance and cost of resources for current state-of-the-art cathode active materials makes the search for alternative cell chemistries inevitable. Nonetheless, especially in solid-state batteries, establishing new cell chemistries comes at the challenge of optimizing the transport of both charge carriers, electrons and ions, through the electrode. Limitations in transport of either species lead to underutilization of the electrode caused by insufficiently contacted particles and/or nonuniform reaction rates and state-of-charge gradients through the electrode. In this work, we investigate the capabilities of Li2FeS2 as alternative active material in all-solid-state cathodes by thorough investigation of the initial utilization and rate capability as a function of the cathode loading. The cathode loading is increased from 1.8 to 7.3 mAh·cm−2 by increasing the fraction of active material from 32 to 74 vol.%, and the thickness of the composite electrode from 73 to 145 μm. Careful characterization of the effective electronic and ionic transport, and consideration of the δ-parameter from porous electrode theory, guides the understanding of the electrode performances. With that, this work shows that Li2FeS2 solid-state cathodes with high areal loadings and gravimetric energy densities can be realized.

Copyright and License

The content is available under CC BY 4.0 [opens in a new tab]
 

Acknowledgement

The authors acknowledge financial support by the Bundesministerium für Bildung und Forschung (BMBF; projects KAROFEST 03XP0498B). We further acknowledge funding from the Deutsche Forschungsgemeinschaft under project number 459785385. The authors acknowledge the help of Andrew J. Martinolich in the early stages of this study.

Supplemental Material

Supporting information: Synthesis details and structural characterization, chronoamperometry and transmission-line modelling of impedance spectra, details of effective-medium modelling, additional information and depictions regarding the electrochemical characterization.

Data Availability

The data that support the findings of this study have been archived at DOI: https://doi.org/10.17879/45968568801.

Contributions

The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. T.B.: Conceptualization, experimental investigation, formal analysis, data curation, writing, visualization. L.K.: Data evaluation, experimental investigation, writing-review and editing. B.H.: Experimental investigation, writing-review and editing. M.A.K.: Conceptualization, methodology, writing-review and editing. K.A.S.: Experimental investigation, writing-editing and review. W.G.Z.: Conceptualization, resources, writing-review and editing, supervision.

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transport-characterization-of-solid-state-li2fe-s2-cathodes-from-a-porous-electrode-theory-perspective.pdf

Additional details

Created:
February 12, 2025
Modified:
February 12, 2025