Modeling chemo-thermal mechanical stresses in all-solid-state lithium Batteries: Influence of grain morphology and alignment

Journal of Power Sources, vol. 653, pp. 237539

Abstract

All-solid-state batteries (ASSBs) are gaining attraction as a safer and more efficient alternative to traditional liquid lithium-ion batteries due to their use of solid electrolytes. However, the advancement of ASSBs is hindered by challenges such as mechanical stress induced by volume changes in the cathode active material (CAM) during cycling. This study investigates the impact of composite cathode grain morphology on the induced mechanical stress within the composite cathode, specifically focusing on the configurations involving spherical and hexagonal LiCoO 2 (LCO) paired with spherical and fiber-shaped garnet-type Li 7 La 3 Zr 2 O 12 (LLZO) electrolytes. Four distinct systems are analyzed: spherical LCO-spherical LLZO, spherical LCO-fiber LLZO, hexagonal LCO-spherical LLZO, and hexagonal LCO-fiber LLZO. By generating modeled microstructures, we investigate the effects of the solid volume fraction of LCO and porosity on the induced chemo-thermal mechanical stress, reflecting real-life scenarios considering induced stresses after sintering. Our findings reveal that fiber LLZO in conjunction with textured hexagonal LCO reduces the induced mechanical stress in both components by 11.0 % for LCO and 9.0 % for LLZO. In contrast, the use of randomly oriented spherical LCO in the composite leads to higher induced mechanical stresses in both LCO and LLZO. The alignment of fiber LLZO critically influences the stress type within the system due to facet-specific contact interfaces, underscoring the importance of grain morphology in optimizing the mechanical performance of ASSBs.

Authors 5

1. Fadi Al‐Jaljouli corresponding Aachen Institute of Mineral Engineering (GHI)

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich GmbH, Institute of Energy Materials and Devices, Materials Synthesis and Processing (IMD-2), 52425, Jülich, Germany

   Institute of Mineral Engineering, RWTH Aachen University, 52064, Aachen, Germany

2. Robert Mücke

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich GmbH, Institute of Energy Materials and Devices, Materials Synthesis and Processing (IMD-2), 52425, Jülich, Germany

3. Martin Finsterbusch

   Forschungszentrum Jülich · Helmholtz-Institute Münster

   Affiliation as printed

   Forschungszentrum Jülich GmbH, Institute of Energy Materials and Devices, Materials Synthesis and Processing (IMD-2), 52425, Jülich, Germany

   Helmholtz Institute Münster: Ionics in Energy Storage (IMD-4 / HI MS), Münster, 48149, Germany

4. Payam Kaghazchi

   Forschungszentrum Jülich · University of Twente

   Affiliation as printed

   Forschungszentrum Jülich GmbH, Institute of Energy Materials and Devices, Materials Synthesis and Processing (IMD-2), 52425, Jülich, Germany

   MESA+ Institute for Nanotechnology, University of Twente, P. O. Box 217, Enschede, 7500AE, the Netherlands

5. Olivier Guillon Aachen Institute of Mineral Engineering (GHI)

   Forschungszentrum Jülich · Helmholtz-Institute Münster · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich GmbH, Institute of Energy Materials and Devices, Materials Synthesis and Processing (IMD-2), 52425, Jülich, Germany

   Helmholtz Institute Münster: Ionics in Energy Storage (IMD-4 / HI MS), Münster, 48149, Germany

   Institute of Mineral Engineering, RWTH Aachen University, 52064, Aachen, Germany

   Jülich Aachen Research Alliance: JARA-Energy, Jülich, 52425, Germany