Chemo-Mechanical Behavior and Stability of High-Loading Cathodes in Solid-State Batteries

Se Hwan Park; Kaustubh G Naik; Bairav S Vishnugopi; Xianghui Xiao; Michael Drakopoulos; Nghia T Vo; Zhong Zhong; Partha P Mukherjee; Kelsey B Hatzell

doi:10.1021/acsnano.5c04431

Chemo-Mechanical Behavior and Stability of High-Loading Cathodes in Solid-State Batteries

ACS Nano. 2025 Jun 24;19(24):22262-22269. doi: 10.1021/acsnano.5c04431. Epub 2025 Jun 11.

Authors

Affiliations

¹ Andlinger Center for Energy and the Environment, Princeton University, Princeton, New Jersey 08540, United States.
² School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
³ Brookhaven National Laboratory, National Synchrotron Light Source II, Upton, New York 11973, United States.
⁴ Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08540, United States.
⁵ Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08540, United States.

PMID: 40498038
DOI: 10.1021/acsnano.5c04431

Abstract

Solid-state batteries can offer higher energy density and improved safety compared to lithium ion batteries, which use flammable liquid electrolytes. Increasing the ratio of cathode active materials in composite cathodes enhances the energy density and reduces manufacturing costs. Changes in the ratio of cathode active materials alter the microstructure and chemo-mechanical response of a cathode during operation. Understanding the relationship between composition, microstructure, and chemo-mechanical interactions is critical for optimizing solid-state cathodes. In this study, we engineered composite cathodes with varying ratios of LiNi_0.8Co_0.1Mn_0.1O₂ and Li₆PS₅Cl to systematically investigate the role of microstructural evolution in long-term chemo-mechanical transformations. Chemo-mechanical stresses resulting from the volume changes of the cathode active materials led to degradation mechanisms, such as fracture and interfacial delamination. Active material fracture and delamination led to underutilization of active material and significant capacity decay during cycling. Coatings that suppress active material-active material interactions during cycling may aid in suppressing the generation of local stress hotspots.

Keywords: cathode; chemo-mechanics; fracture; solid-state batteries; stress.