Experimental and theoretical analysis of the eruption processes of abused prismatic Ni-rich automotive batteries based on multi-parameters

Abstract

Lithium-ion battery (LIB) eruptions are mainly responsible for battery fires in electric vehicles. This study aims to quantitatively reveal the LIB eruption process. A 50 Ah commercial prismatic cell with a Li(Ni0.6Mn0.2Co0.2)O2 cathode is triggered to thermal runaway in a sealed chamber with a nitrogen atmosphere. The in-cell pressure near the safety valve (P), the cell side surface center temperature (T1), and the cell jet temperatures are detected. A new method is proposed and used to analyze the cell eruption process based on these parameters. Eight thresholds of time are extracted and the cell eruption process can be divided into an in-cell pressure establishment stage, including slow, fast, and ultrafast substages; an eruption stage, including first and second substages; a pressure increase stage, and a pressure decrease stage. During the transition from the fast to the ultrafast substages, P and T1 have obvious changes. All these parameters detected decrease at the beginning of the first eruption, but increase at the beginning of the second eruption. Thus, the results of this study can provide more guidance for gas generation research, gas identifications, fire early warning designs, fire suppression strategy developments, proper cell selections and storage designs for LIBs.