Real-Time Stress Measurements in Lithium-ion Battery Negative-electrodes

Abstract

Real-time stress evolution in a graphite-based lithium-ion battery negative-electrode during electrolyte wetting and electrochemical cycling is measured through wafer-curvature method. Upon electrolyte addition, the composite electrode rapidly develops compressive stress of the order of 1-2 MPa due to binder swelling; upon continued exposure, the stress continues to evolve towards an apparent plateau. During electrochemical intercalation at a slow rate, the compressive stress increases with the electrode's state-of-charge, reaching a maximum value of 10 - 12 MPa. There appears to be an approximate correlation between the rate of stress rise and the staging behavior of the lithiated graphite. De-intercalation at a slow rate results in a similar linear decrease in electrode stress. Tensile stress of a few MPa develops at the end of deintercalation in the first few cycles, after which the electrode remains under compressive stress only. Although higher peak stresses are seen at high C-rates, the dependence appears to be relatively weak (up to 5C). These measurements reveal, for the first time, the nature of stress evolution in practical lithium-ion-battery electrodes and provide useful data to quantify the driving force for mechanical damage that accrues in composite electrodes upon repeated cycling. While the reported results can serve as reference for calibrating theoretical and computational models to predict electrode stress and damage evolution, the methodology demonstrated can be used to measure stresses and characterize fatigue damage in any composite lithium-ion-battery electrode as well as optimize its microstructure to mitigate stress-related damage mechanisms.

arXiv comment22 pages, 8 figures; Journal of Power Sources, 201, 2012

References in corpus (6)

• In Situ Measurements of Stress Evolution in Silicon Thin Films During Electrochemical Lithiation and Delithiation
• A Finite Strain Model of Stress, Diffusion, Plastic Flow and Electrochemical Reactions in a Lithium-ion Half-cell
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• In Situ Measurements of Stress-Potential Coupling in Lithiated Silicon
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• In situ Measurement of Biaxial Modulus of Si Anode for Li-ion Batteries

Cited by in corpus (6)

• Intercalation kinetics in multiphase layered materials
• Stress Evolution in Lithium-ion Composite Electrodes during Electrochemical Cycling and Resulting Internal Pressures on the Cell Casing
• Stress Evolution in Composite Silicon Electrodes during Lithiation/Delithiation
• A mathematical model for mechanically-induced deterioration of the binder in lithium-ion electrodes
• Influence of elastic strain on the thermodynamics and kinetics of lithium vacancy in bulk LiCoO2
• Advancing Measurement Capabilities in Lithium-Ion Batteries: Exploring the Potential of Fiber Optic Sensors for Thermal Monitoring of Battery Cells