EXPERIMENTAL RESEARCH OF TESLA MODEL S POWER BATTERY CELLS FOR OPEN FLAME FIRE HAZARD

Abstract

Introduction. The number of electric vehicles continues to grow. As of the first quarter of 2024, according to the Main Service Centre of the Ministry of Internal Affairs, 93976 electric vehicles were registered in Ukraine. At the same time, in 2019-2024, the units of the State Emergency Service of Ukraine registered 173 electric vehicle fires in Ukraine, which caused direct losses of UAH 9 million 53 thousand and indirect losses of UAH 18 million 450 thousand.
Purpose. Is to develop the main provisions of the methodology for experimental studies of lithium-ion battery modules of electric vehicles in terms of open flame fire hazard. The ultimate goal of the study is to determine the thermal parameters (temperature of venation holes, ignition, irreversible exothermic reaction, combustion, etc.) that describe the combustion processes of lithium-ion battery modules of electric vehicles, as well as to reveal the peculiarities of the development and spread of combustion in the module of a lithium-ion battery of an electric vehicle.
To do this, it is necessary to identify the necessary equipment and measuring instruments (hereinafter referred to as M&I); justify the model fire, the placement of M&I on the research module; justify the procedure for conducting full-scale fire tests with ensuring labour safety conditions, as well as the procedure for processing the obtained experimental data.
Methods of research. The research used experimental and theoretical research methods. The theoretical research method used such operations as synthesis, analysis, systematisation, generalisation, etc.
Material description. The essence of the proposed methodology is to determine the temperature of ventilation holes, ignition, and the occurrence of an irreversible exothermic reaction, to study the influence of factors on these parameters, and to reveal the features of the development and propagation of combustion in the module of an electric vehicle lithium-ion battery. To create a heat flux in the sample under study, it is necessary to identify the heat source and justify its parameters. Class C model fires were selected as a scientific study. The advantage of such model fires is the simplicity of the gas burner installation, the ability to regulate the gas supply, etc. To place the thermocouples, through holes are made in the test module with a diameter that will allow the placement of thermocouples, but not more than 3 mm. A digital multimeter is used to determine the internal short circuit that occurs as a result of the separator destruction and the short circuit of the cathode and anode of the lithium-ion cell. The digital multimeter is connected to the poles of
the lithium-ion cell using a two-core copper conductor with a diameter of 1.5 mm² (to reduce the resistance on the conductor and increase the measurement accuracy) and determines the voltage drop across the cell.
Conclusions. The article develops a methodology for experimental research of modules of lithium-ion batteries of electric vehicles under the influence of an open flame of a class C model fire. The use of this methodology will make it possible to determine the temperature of venation holes, the occurrence of an irreversible exothermic reaction and ignition of a module of lithium-ion batteries of electric vehicles, as well as to outline the features of the propagation of an irreversible reaction along the module. The criteria for the placement of the gas burner, gas consumption and placement of measuring equipment are experimentally substantiated, and the procedure for conducting the experiment and processing the obtained experimental data are described.