a b s t r a c t
A quasi-static mechanical abuse test program on cylindrical Lithium ion battery cells has been performed
at a state of charge (SoC) of 0%. The investigated load cases involved radial crushing, local lateral
indentation and global three-point bending of the cell. During the tests, the punch load, the punch
displacement, the cell voltage and the temperature development of the cell have been monitored using
an infrared camera and temperature sensors. After the test, the cells have been analysed using computer
tomography.
It is indicated that macroscopic jelly roll fracture on a global scale initiates the internal short circuits,
revealed by a sudden decrease of the global mechanical load due to the rupture, followed by a drop of the
measured voltage and immediate increase in cell temperature.
A macro-mechanical finite element crash simulation model has been established for the cell housing
and the jelly roll. The classical stress-based criterion after Mohr and Coulomb (MC) has been applied to
predict fracture and the initiation of an internal short circuit of the jelly roll. The MC criterion correctly
represents the punch displacement to fracture, where the predicted fracture locations correspond to the
observed locations of the internal short circuits of the cells.