Research progress on typical failure mode diagnosis and early warning of power battery for NEVs

With the rapid development of the new energy vehicle industry and the escalating ownership rates, thermal runaway problem in power battery has emerged as a significant barrier to the widespread adoption of new energy vehicles. This paper first elucidates the requirements for thermal runaway phenomenon through an examination of heat generation and dissipation dynamics in battery, unveiling the chain reaction process and corresponding chemical equations. Next, it encapsulates the prevalent failure modes at both system and individual levels, particularly highlighting internal short circuit, capacity degradation and electrolyte leakage, and introduces the failure analysis process after product recall, leveraging insights from experience of a battery manufacturer. Subsequently, the focus shifts to cutting-edge diagnostic techniques prevalent in both academic and industrial realms, detailing the attributes and prospective trajectories of each method. Finally, a multidimensional safety early warning framework that melds mechanisms with data analytics is proposed. Additionally, the potential implementation avenues and application scenarios of emerging large model technologies within the battery field are prospected. This paper aims to promote fault diagnosis and early warning technologies for power batteries, thereby fostering the sustainable growth of the new energy vehicle industry.