Abstract

Composite cathode composed of active particles and solid electrolytes (SEs) can considerably enlarge the particle-SE contact areas and achieve high areal loadings in all-solid-state batteries (ASSBs). However, the challenging interfacial instability and particle damage problems remain unsolved. Herein, we establish a 3D electrochemical-mechanical coupled model to investigate the underlying failure mechanism by considering the governing electrochemical and physics processes. Micro-scale heterogeneous primary particles with random crystallographic orientation and size inside the LiNi_1/3Co_1/3Mn_1/3O₂ (NCM111) secondary particle of the model result in the anisotropic Li diffusion and volume variation within the secondary particle, leading to significant nonuniformity of the Li concentration, and GPa-level stress distributions at primary particle boundaries, and finally causing the particle internal cracks. The particle volume shrinkage under the constraint of stiff Li₇La₃Zr₂O₁₂ (LLZO) SE triggers the interface debonding (gap>50 nm) with increased interfacial impedance to degrade cell capacity. Higher C-rates result in larger residual stress (~100 MPa)/strain/debonding gap at dis-charging end, more likely to deteriorate the cell performance. Increasing the interfacial strength between the particle and SE can suppress the interface debonding but induces high stress (up to 10 GPa). In conclusion, results reveal the underlying mechanism of the electrochemical-mechanical coupling failure mechanism for composite cathode and providemore » promising guidance on the further improvement of a more robust composite cathode for ASSBs.« less

Authors:

Yuan, Chunhao ^[1]; Lu, Wenquan ^[2]; Xu, Jun  ^[1]

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+ Show Author Affiliations

1. University of North Carolina, Charlotte, NC (United States)
2. Argonne National Laboratory (ANL), Argonne, IL (United States)

Publication Date:

Thu Jun 01 00:00:00 EDT 2023

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Sustainable Transportation. Vehicle Technologies Office (VTO); USDOE

OSTI Identifier:

2222698

Alternate Identifier(s):

OSTI ID: 1983688

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

Energy Storage Materials

Additional Journal Information:

Journal Volume: 60; Journal ID: ISSN 2405-8297

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE; All-solid-state battery; Composite cathode; Electrochemical-mechanical coupling; Failure; Interfacial instability