The rapid growth of electric mobility and energy storage systems has intensified the demand for higher capacity lithium-ion battery cells, while simultaneously increasing safety requirements under abusive loading conditions. In this context, the present study investigates the mechanical behavior of high-performance 21700 cylindrical lithium-ion battery cells subjected to severe mechanical abuse. The work focuses on the combined influence of loading velocity and state of charge (SoC) on cell deformation and failure, and on the development of a robust finite element analysis (FEA) model capable of predicting internal short-circuit initiation. Experimental investigations were conducted using hydraulic flat-compression tests performed at four states of charge (40%, 60%, 80%, and 100%) and three loading velocities (10 mm/s, 100 mm/s, and 1000 mm/s) [1]. These tests provided insight into the rate-dependent and SoC-dependent mechanical response of the cells under high compressive loads. Based on the experimental results, a homogenized FEA model was developed using the explicit solver capabilities of OpenRadioss [2]. The model is designed to capture internal damage mechanisms, particularly separator failure [3], which can trigger internal short-circuits and potentially lead to thermal runaway. The proposed modeling approach, combined with well-identified material properties and fracture parameters, demonstrates strong predictive capability across a wide range of mechanical loading conditions and states of charge in full-vehicle crashworthiness simulations.