Analysis of Interfacial Effects in All-Solid-State Batteries with Thiophosphate Solid Electrolytes

Anton Neumann; Simon Randau; Katharina Becker-Steinberger; Timo Danner; Simon Hein; Ziyang Ning; James Marrow; Felix H Richter; Jürgen Janek; Arnulf Latz

doi:10.1021/acsami.9b21404

Analysis of Interfacial Effects in All-Solid-State Batteries with Thiophosphate Solid Electrolytes

ACS Appl Mater Interfaces. 2020 Feb 26;12(8):9277-9291. doi: 10.1021/acsami.9b21404. Epub 2020 Feb 10.

Authors

Anton Neumann^{1

2}, Simon Randau^{3

4}, Katharina Becker-Steinberger^{1

2}, Timo Danner^{1

2}, Simon Hein^{1

2}, Ziyang Ning⁵, James Marrow⁵, Felix H Richter^{3

4}, Jürgen Janek^{3

4

6}, Arnulf Latz^{1

2

7}

Affiliations

¹ German Aerospace Center (DLR) , Institute of Engineering Thermodynamics , Pfaffenwaldring 38-40 , 70569 Stuttgart , Germany.
² Helmholtz Institute for Electrochemical Energy Storage (HIU) , Helmholtzstraße 11 , 89081 Ulm , Germany.
³ Institute of Physical Chemistry , Justus-Liebig-University Giessen , Heinrich-Buff-Ring 17 , 35392 Giessen , Germany.
⁴ Center for Materials Research (LaMa) , Justus-Liebig-University Giessen , Heinrich-Buff-Ring 16 , 35392 Giessen , Germany.
⁵ Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom.
⁶ Battery and Electrochemistry Laboratory (BELLA), Institute of Nanotechnology , Karlsruhe Institute of Technology , Hermann-von-Helmholtz Platz 1 , 76344 Eggenstein-Leopoldshafen , Germany.
⁷ Ulm University (UUlm) , Institute of Electrochemistry , Albert-Einstein-Allee 47 , 89081 Ulm , Germany.

PMID: 32040288
DOI: 10.1021/acsami.9b21404

Abstract

All-solid-state batteries (ASSBs) present a promising route toward safe and high-power battery systems in order to meet the future demands in the consumer and automotive market. Composite cathodes are one way to boost the energy density of ASSBs compared to thin-film configurations. In this manuscript, we investigate composites consisting of β-Li₃PS₄ (β-LPS) solid electrolyte and high-energy Li(Ni_0.6Mn_0.2Co_0.2)O₂ (NMC622). The fabricated cells show a good cycle life with a satisfactory capacity retention. Still, the cathode utilization is below the values reported in the literature for systems with liquid electrolytes. The common understanding is that interface processes between the active material and solid electrolyte are responsible for the reduced performance. In order to throw some light on this topic, we perform 3D microstructure-resolved simulations on virtual samples obtained via X-ray tomography. Through this approach, we are able to correlate the composite microstructure with electrode performance and impedance. We identify the low electronic conductivity in the fully lithiated NMC622 as material inherent restriction preventing high cathode utilization. Moreover, we find that geometrical properties and morphological changes of the microstructure interact with the internal and external interfaces, significantly affecting the capacity retention at higher currents.

Keywords: 3D microstructure-resolved simulations; all-solid-state batteries; impedance analysis; microcomputer tomography; nickel-rich layered oxides; thiophosphate solid electrolyte.