Micro-Cell Level Thermal Runaway Tests for Multiple Layers of High-Capacity Lithium-Ion Batteries

Abstract

Lithium-ion batteries (LIBs) are a vital power source for numerous applications, yet their potential for thermal runaway (TR) poses serious safety risks, particularly with the trend towards higher energy densities. This research investigates the TR behavior of LIB components in multi-layer arrangement via the thermochemical analysis. The study involves analyzing the samples comprised of a set of anode, cathode, and separator from 88% nickel and 91% nickel cathode-based LIBs in a sealed and controlled environment. Various heating rates of 10°C/min, 15°C/min, and 20°C/min are used to stimulate thermal stress scenarios. A novel testing method is developed where a miniaturized LIB is stacked in multiple layers. Each layer, representative of a single segment of the LIB, is subjected to the evaluation on its thermal interaction and dissipation leading to a TR. The results highlight how different heating rates and layered configurations impact the onset and progression of TR. The interpolation technique is developed to predict the TR behavior of massively stacked layers from the micro-cell set up. Thus, the feasibility of the multi-layer, micro-cell TR testing methodology is demonstrated by comparing the predictions to available physical data in real LIB systems.

Keywords: - Lithium-ion batteries, Thermal runaway, Multiple layer, Activation energy, Micro-cell