Advancing Safe Battery Design through Experimental Cell Characterization of Thermal, Electrical and Mechanical Properties

Lithium-ion batteries are critical to electric vehicles and grid-scale energy storage. Safe design of battery systems relies on accurate simulation of battery thermal runaway under electrical, thermal, and mechanical abuse. A predictive battery simulation requires the characterization of electrical, thermal, and mechanical properties of the battery at the full cell and cell-component levels. In this study, a commercial cell from an electric vehicle was disassembled, and testing was conducted to support both homogenized and detailed computational models. At the cell level, electrical properties were characterized using Hybrid Pulse Power Characterization (HPPC) testing to assess the cell power capability. Cell punch tests were conducted to characterize mechanical behavior under deformation. These tests were used to develop a multi-physics homogenized cell model. On the other hand, detailed cell modeling that includes different component layers could help users understand localized cell integrity under mechanical deformation. At the component level, cathode and anode electrodes, separator, and cell pouch laminate were tested for their thermal properties, including heat capacity, thermal conductivity, and melting points. This data is essential to model heat generation and dissipation in the detailed battery cell model. Mechanical behavior of these component materials was tested to understand structural integrity and failure modes. These experimentally measured properties and derived parameters may be integrated into a representative multi-physics battery cell model. By providing characterization of lithium-ion battery cell, this research provides experimental framework for developing both macro and detailed cell computational models that are used for safety design assessments of EV battery systems.