Towards Determining an Engineering Stress-Strain Curve and Damage of the Cylindrical Lithium-Ion Battery Using the Cylindrical Indentation Test

• Published in: Batteries (Basel) Vol. 9; no. 4; p. 233
• Main Authors: Voyiadjis, George Z., Akbari, Edris, Łuczak, Bartosz, Sumelka, Wojciech
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.04.2023
• Subjects: Analysis; Bearing strength; Contact stresses; Damage assessment; Deformation; Design and construction; Electric vehicles; fractional damage; Hardness tests; Indentation; internal short circuit; Lithium cells; Lithium-ion batteries; lithium-ion battery; Load carrying capacity; Mathematical models; Mechanical properties; Modulus of elasticity; Propagation; Rechargeable batteries; safety; Short circuits; Stress-strain curves; Stress-strain relationships; Testing; Voltage reduction; United States
• ISSN: 2313-0105; 2313-0105
• DOI: 10.3390/batteries9040233

Mechanical internal short circuit (ISC) is one of the significant safety issues in lithium-ion battery design. As a result, it is possible to subject LIB cells to thorough mechanical abuse tests to determine when and why failure may occur. The indentation test is a recommended loading condition for evaluating mechanical damage and ISC. In this study, 18,650 cylindrical battery cells underwent indentation tests and a voltage reduction following the peak force identified by the ISC. Due to the complexity of the contact surface shape between two cylinders (LIB cell and indenter), a new phenomenological analytical model is proposed to measure the projected contact area, which the FEM model confirms. Moreover, the stress-strain curve and Young’s modulus reduction were calculated from the load-depth data. In contrast to previously published models, the model developed in this paper assumes anisotropic hyperelasticity (the transversely isotropic case) and predicts the growing load-carrying capacity (scalar damage), whose variation is regulated by the Caputo-Almeida fractional derivative.