Journal
EXPERIMENTAL MECHANICS
Volume 58, Issue 4, Pages 549-559Publisher
SPRINGER
DOI: 10.1007/s11340-017-0292-0
Keywords
Fracture; NMC; Stresses; Primary particles; Li-ion batteries
Categories
Funding
- National Science Foundation [CBET-1603866]
- Office of Naval Research through the NEPTUNE program
- U.S. Department of Energy [DE-AC05-00OR22725]
- Office of Energy Efficiency and Renewable Energy Vehicle Technologies Office (VTO) Applied Battery Research (ABR) subprogram
Ask authors/readers for more resources
Mechanical degradation of Li-ion batteries caused by the repetitive swelling and shrinking of electrodes upon electrochemical cycles is now well recognized. Structural disintegration of the state-of-art cathode materials of a hierarchical structure is relatively less studied. We track the microstructural evolution of different marked regimes in LiNi (x) Mn (y) Co (z) O-2 (NMC) electrodes after lithiation cycles. Decohesion of primary particles constitutes the major mechanical degradation in the NMC materials, which results in the loss of connectivity of the conductive network and impedance increase. We find that the structural disintegration is largely dependent on the charging rate - slow charging causes more damage, and is relatively insensitive to the cyclic voltage window. We use finite element modeling to study the evolution of Li concentration and stresses in a NMC secondary particle and employ the cohesive zone model to simulate the interfacial fracture between primary particles. We reveal that microcracks accumulate and propagate during the cyclic lithiation and delithiation at a slow charging rate.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available