Although lithium batteries bring convenience to people’s lives, its safety is concerned with everyone. The explosion temperature of the electrolyte enters the metal plate and the explosion limit of the pyrolysis gas is higher than that of the hydrocarbons. The thermal reaction of lithium batteries is easy to cause dangerous events, and its high temperature characteristics are an important and fundamental factor of fire hazards. Therefore, it is important to analyze the impact of the environment and the release temperature of lithium batteries to reduce the risk of their use.
Overview of lithium thermal runaway batteries
The lithium battery charging process includes two types: primary discharge and secondary discharge. During the first discharge, the temperature inside the lithium battery will rise. If the pressure increases, the auxiliary port of the lithium battery will open and release smoke constantly. During the discharge process, the lithium battery will have a severe pinch problem. A large amount of light will be sprayed from the positive pole of the battery, and the second light will be made at the same time. In the low voltage region, smoke is provided
Effect of low environmental pressure on battery thermal runaway
Effects of low pressure environments on lithium-ion battery cells
In the lithium battery light bulb and the chip system, when the battery charge is different, the ambient pressure drop will cause the battery response condition to rise. Therefore, the higher the pressure, the greater the chance of lithium battery explosion. At the same time, the light output of the lithium battery will decrease with the increase in load, and this process will not affect the pressure conditions.
Effect of low pressure environment on injection port of lithium-ion battery
In a thermal reaction, the heat in the output of the positive cell of the battery is the heat provided by the reaction. The energy source of thermal runaway usually includes the following content: First, the energy released by the second combustion reaction of the fuel and the heat generated by the heat runaway in different pressure environments . Second, the high temperature and energy produced by the rapid thermal reaction inside the lithium battery.
(1) 30kPa ambient pressure
At a low pressure of 30 kPa, the temperature of the hot runner is measured at the exit of the positive jet battery and is divided into five levels: 1 to 4 high temperature surface focusing on ‘reaction time of the running temperature of seven batteries; peaks 1 and 2 occur during the first and second heat reactions, and the peak width is narrow and the high temperature is short; Parts of peaks 3 and 4 occurred in the third to seventh stages of the lithium battery’s thermal reaction, while the temperature of peak 3 was low, while peak 4 occurred at the time when the lithium ion battery’s thermal reaction enough. The temperature of peak 4 is close to that of peak 5, and the temperature is high; a maximum value of 5 indicates that the reaction of the light bulb is complete.
(2) 60kPa ambient pressure
The fast burning reaction of the battery forms a process of combustion and explosion by spreading bright and high-temperature materials, and creates a lot of heat. When the pressure condition is 60 kPa, the lithium-ion battery has 7 thermal reactions. From the investigation of the temperature of the port of the lithium battery, it is found that there are 5 thermal runaway high temperature surface and reaction, of which 1 to 4 high temperature surfaces is focused on the seventh thermal runaway reaction. The maximum value of the high temperature 5 of lithium ion appears after the end of the reaction of the discharge of the battery seven. At this time, the potassium ion battery loses fuel in the plastic membrane to produce a high amount of heat through the thermal reaction. The temperature of surface 2, 3 and 4 is around 800 ℃, and the maximum temperature is around 1100 ℃. The width of the top is narrow. Compared to a pressure environment of 101kPa, seven pyrotechnic reactions occurred at an environment of 60kPa: the peak of the lithium-ion battery port is four, and the analysis shows that the pyrotechnic elements are ignited by the reaction and – running on Look has a small effect on high temperature. If the maximum value is more than 600 ℃, the width will be reduced.
