The environment of high temperature causes 18650 lithium ion battery thermal runaway?

Source: 2020 - 04 - 10 then hits: time result in high temperature environment 18650 lithium-ion batteries, lithium ion battery thermal runaway due to its high working voltage, high power density and energy density, charge and discharge advantages of long service life, no memory effect, no pollution, is widely used in notebook computers, cameras, mobile phones and other electronic components of various kinds. In recent years, its application is extended to large and medium-sized power or energy storage equipment/facilities, such as electric power, renewable energy and energy storage, backup power communication network, military reserve power supply, etc. Lithium ion battery may well become a 21st century green energy storage/supply. 18650 on behalf of the external dimensions: the number in the lithium ion battery cell diameter of 18 18 said. 0 mm, 650 said cell height is 65. 0mm。 The theory of 18650 type lithium ion battery life expectancy of 1000 time charge, is mainly used in notebook computers. In addition, because working stability is very good, also widely used in the electronics field, often used in high-end flashlight, portable power supply, wireless data transmission equipment, insulation suits, portable instruments and lighting equipment, portable printer, industrial instrumentation, medical equipment, etc. The safety of the lithium ion battery has been the main problems of restricting the further development. With the use of lithium ion battery is becoming more and more complicated, they are more and more frequently exposed to higher temperature, the temperature inside the battery as the external temperature rises. Due to the strong exothermic reaction, battery temperature suddenly increases, lead to thermal runaway, may cause the phenomenon such as fire, explosion. Domestic and foreign scholars have studied the thermal runaway of lithium ion batteries, including battery materials of thermal stability, the mechanism of the thermal runaway and seek for a safe battery materials, etc. Hatchard etc. Through the establishment of one-dimensional heat furnace model of lithium ion battery, predicting the lithium ion battery in the process of heat furnace thermal behavior. Spotnitz people such as the establishment of a lithium ion one-dimensional layered model, the abuse of lithium ion batteries are simulated by the oven test, found that negative binder in the process of thermal runaway played a small role. Kim, etc. Through the establishment of lithium ion battery of the three-dimensional thermal abuse model, simulates the different sizes cylindrical battery in the evolution of the temperature field in the 155 ℃ oven test, study the diffusion process in the chemical reactions in the battery. Lai Pengfei such as the establishment of a lithium ion battery oven cylindrical three-dimensional numerical model, studies the influence of temperature and charging status of the battery thermal runaway, puts forward the analysis method for determining thermal safety critical curves. These theories and related experiments to understand the lithium ion battery under the environment of high temperature thermal runaway. However, these studies are based on the oven test, rarely involves the lithium ion battery under the condition of constant power heating process of thermal control and heat release.