Experimental evaluation of fi re hazard of lithium-ion battery during its mechanical damage

Abstract

Purpose. To experimentally determine the combustion temperature of a lithium-ion battery (LIB) due to mechanical damage to its case by a sharp object. At the same time, to determine the cooling-down time of the lithium-ion battery after combustion and the further mathematical description of this process. Methodology. To achieve the set goal, a laboratory bench with the appropriate measuring equipment was prepared. For mathematical modelling of the cooling process, experimental values and methods for studying heat transfer processes in solid multilayer cylindrical structures were applied. Findings. Experimental studies showed that the maximum temperature on the lithium-ion battery case reached 715 °C. In turn, the average values showed a temperature of 665 °С. The average cooling time to a temperature of 50 °C was at least 17 minutes. Mass loss studies showed that after combustion are complete, all elements lose about 53 % of their original mass. Originality. The combustion temperature and cooling-down time of Panasonic NCR18650B (LiNi0.8Co0.15Al0.05O2) LIB specifi cally have been determined for the fi rst time. In parallel with experimental studies, mathematical modelling of the cooling process of the LIB was carried out using the theory of heat transfer. It was found that the results of the mathematical modelling correlate well with the experimental values. This approach allows, in the future, carrying out analytical studies on LIB without the need (where possible) to conduct experiments. Practical value. Further implementation and application of the obtained mathematical model will make it possible to determine the cooling time, the possibility of heating other (adjacent) LIB to a critical temperature, the possibility of ignition from overload, various LIB using only geometric parameters without the need for experimental research. Determining the cooling time of the LIB after combustion is a valuable indicator since it allows one to practically estimate the time during the LIB remains a potential source of danger.