Causes of internal short circuit of lithium battery

In-depth analysis of microscopic and macroscopic power non-combustion battery technology: saving lithium batteries In 2015, my country's new energy vehicle sales exceeded 300,000 units, and the market has gradually entered a rising period from the lead period. The power demand for lithium batteries has soared. Work with the industry to improve the safety and stability of power lithium-ion batteries. According to statistics, since 2015, there have been 7 spontaneous combustion accidents of pure electric buses and hybrid buses across the country. The main cause of the fire was the failure of the power lithium-ion battery. To this end, the Ministry of Industry and Information Technology announced the suspension of listing ternary lithium battery passenger vehicles in the list of recommended models for the promotion and use of new energy vehicles, and the work of ternary lithium batteries is in trouble. In the case that the lithium battery safety technology has not been broken for a long time, on March 19th, Beijing Water Cube, Weihong Power announced the technology of Weihong non-burning battery, which has made technology for the safety of lithium batteries in the market. It also became the first company to announce that it would not burn batteries. In order to allow readers to quickly know the different techniques, the author here makes an in-depth analysis of the microscopic and macroscopic non-burning batteries. Lithium batteries are fuel tanks with matches. Before we discuss non-burning batteries, we need to know the reason why lithium batteries burn. We have all learned in chemistry that combustion has three basic components: combustibles, combustibles, and ignition sources. Lithium batteries supply all of this, for example in the form of a fuel tank with matches. Lithium batteries have poor thermal stability. They will decompose and release oxygen at an external temperature of about 200°C, which is somewhat related to the battery's combustible electrolyte and carbon data. The explosion of heat will further aggravate the decomposition of the anode, and a heat escape similar to gunpowder will appear. Once a lithium battery catches fire, it will deflate within a short period of time. For example, a Hong Kong-branded bus using a ternary lithium battery last year was flattened and burnt down within a few seconds. This is a typical example. The internal short circuit constitutes the thermal runaway of the battery, but the battery will not reach the condition of battery incineration during the normal use of the battery. So what is the important reason for the thermal runaway of the lithium battery? The internal battery short circuit. There are many reasons for the internal short circuit of lithium batteries, which can be divided into external reasons and uncontrolled internal reasons. Planning is unstable and the environment is harsh. Mechanical disasters can be prevented through electronic equipment and mechanical planning, but some internal causes cannot be completely prevented. Due to the influence of the data system and manufacturing process, the lithium battery has the risk of internal short circuit. Although lithium batteries have undergone severe aging and self-discharge options when they leave the factory, due to unpredictable application factors such as process failures, there is still a certain failure probability during the application process, leading to the occurrence of internal short circuits. For every 100,000 vehicles sold, 1600 vehicles face a high risk of spontaneous combustion, which is calculated based on the current industry’s highest standard of 18650 batteries per 2ppm. As for power lithium-ion batteries, there are hundreds or even tens of thousands of lithium batteries in the battery pack, which greatly increases the possibility of battery pack bursting. Due to the high energy of power lithium-ion battery packs, the outbreak of internal short circuits is likely to induce vicious events, causing casualties and property losses. The microscopic and macroscopic non-burning of batteries mainly comes from the three techniques of electrolyte, lithium ion gap and thermal control liquid, which facilitate the modification of the defects of lithium batteries and can prevent the burning of lithium batteries to the greatest extent. Research on non-burning electrolyte shows that lithium batteries are out of control when they are attacked by heat. The most heat is the electrolyte, so not burning the electrolyte is the most important issue to ensure that the battery is not burned. For this reason, Weihong has developed a new electrolyte from scratch with the policy of no burning, fast charging, and turtle life. Lithium Ion Barrier With the research on the gap of non-incineration electrolyte and another most important component of lithium battery, Weihong Power also handed over the answer sheet. The barrier of a lithium battery usually has a low melting point, and it will shorten at about 130 degrees Celsius, which will cause a short circuit inside the battery and an out of control thermal attack. Micro and macro put forward the idea of u200bu200busing Kevlar data as the theme to research and develop high temperature barriers. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous article: What is prelithiation?