X-ray computed tomography and simultaneous multi-signal detection for evaluation of thermal runaway of lithium-ion battery

Early warning of thermal runaway (TR) scenarios is one of the most effective and important ways to prevent accidents in lithium-ion battery (LIB) safety management. Herein, TR characteristics of 18,650 LIB are carefully investigated using X-ray computed tomography (X-CT) and simultaneously multi-signal method. The results show that after the first gas venting, TR of LIB may not necessarily and spontaneously occur within a certain temperature range. The X-CT reveals that TR originally occurs in the central area along the axial direction of the LIB, and then it expands to the surface layer of the LIB during thermal abuse. Internal electric short circuit occurs at 100°C and structural damage occurs at 110°C. The first gas venting time is almost simultaneously as the first TR temperature rising, which provides a very effective way to anticipate early TR, guaranteeing enough time for handling of LIB accident and supplying chances for people escaping.