Computed Tomography Analysis of Li-Ion Battery Case Ruptures
- PDF / 1,267,389 Bytes
- 14 Pages / 439.37 x 666.142 pts Page_size
- 87 Downloads / 276 Views
Computed Tomography Analysis of Li-Ion Battery Case Ruptures Lingxi Kong * and Michael Pecht, Center for Advanced Life Cycle Engineering, University of Maryland, College Park, MD 20742, USA Xiaosong Hu, Department of Automotive Engineering, Chongqing University, Chongqing City 400044, China Guan Gui, College of Telecommunications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210003, China Yan Su, College of Civil Aviation, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China Received: 8 November 2019/Accepted: 11 May 2020
Abstract. Battery explosion incidents hinder the development and application of Liion batteries. This paper describes the use of nondestructive computed tomography (CT) to analyze cylindrical Li-ion battery samples that underwent thermal runaway and exploded. Unlike destructive analysis methods, which can lead to a loss of battery structural information, CT scan allows direct observation of a battery’s internal structure without disassembly. In this study, two case studies of 20700 and 18650 batteries show that sidewall and bottom case rupture was caused by blockage of the battery vent region, which prevented the release of the generated gas. This work demonstrates the ability of CT for post-mortem incident analysis and the limitations of current vent design, and also gives insight to a safety issue with some cylindrical batteries. Keywords: Lithium-ion battery, CT scan, Thermal runaway, Exterior case rupture, Cylindrical battery
1. Introduction Li-ion batteries dominate the rechargeable battery market, but their safety is a major issue that has aroused public concern and attracted the attention of researchers [1–4]. For example, the Federal Aviation Administration (FAA) reported 252 lithium battery-related incidents on airplanes as of October 1, 2019 [5]. The concern is that the combination of high energy density electrode, flammable separator, and volatile electrolyte makes Li-ion batteries fire-prone and explosive. If a Li-ion battery is short-circuited or exposed to high temperature, exothermic reactions can be triggered, resulting in a self-enhanced increasing-temperature loop known as ‘‘thermal runaway.’’ Various researchers have investigated the thermal runaway process. Zhong et al. [6] conducted thermal runaway tests on both single * Correspondence should be addressed to: Lingxi Kong, E-mail: [email protected]
1
Fire Technology 2020 lithium-ion batteries and battery modules. For the single battery tests, the authors used a 200-W heater to heat batteries with 0%, 50%, and 100% SOC. Thermal runaway occurred inside the batteries around 30–70 s after the battery venting. Huang et al. [7] conducted both experimental and modeling analyses of battery modules with Li4Ti5O12 anode and found that the gas generation rate can reach 0.748 L/s. If the same rate is assumed to apply to a typical 18650 battery, the gas generated in 1 s can be as high as 45 times the battery volume. Thermal runaway in battery packages/modules has also been studie
Data Loading...
