Wu Yang, CEO of Weihong Company, introduced that when Weihong began to focus on the research and development of electric vehicle power systems in 2008, it established 10-minute fast charging (electric vehicle mobility guarantee) and long life (realizing the entire life cycle of electric vehicles). , Non-burning (to ensure that electric vehicles will not spontaneously ignite without warning) three key elements, "ten minutes fast charge" and "long life" battery technology has more than 10,000 sets of battery technology in 6 countries and more than 100 cities around the world. application. And what is released this time is exactly the non-combustion battery technology result developed by Weihong for 8 years.

　　The current industry disputes on battery safety technology are mainly concentrated on the cathode material and the BMS battery management system. Especially at the Forum of the Hundreds of Electric Vehicles at the beginning of this year, the Ministry of Industry and Information Technology stated that it would organize a risk assessment of ternary lithium batteries and suspend ternary lithium battery buses to be included in the list of recommended models for the promotion and application of new energy vehicles. Wu Yang said that whether the battery burns or not has little to do with the cathode material. The battery is composed of four materials: positive stage, negative stage, electrolyte and diaphragm. The short circuit in the battery causes thermal runaway and fire. It is safe to release the heat as soon as possible.

　　In solving the problems of the electrolyte and separator inside the lithium-ion battery, it is equivalent to proactively setting up defensive measures for non-combustible batteries. In terms of battery system level safety, Weihong also demonstrated the safety advantages brought by the STL intelligent thermal fluid technology using immersion methods. As a material with excellent insulation, flame retardancy and thermal conductivity, STL can quickly isolate the thermal runaway point in the case of a small internal short circuit inside the battery pack, and at the same time use liquid to reduce the temperature of the thermal runaway point to minimize the battery pack Security Risk. As a passive defense system, in addition to safety, STL can also balance the internal temperature difference of the battery pack and use external circulation to achieve better temperature control. At the same time, even if the battery pack leaks, it can be found through liquid detection in time, which is safer. Assure.

　　The two active defense measures of non-burning electrolyte and high temperature resistant diaphragm, combined with the passive defense measure of STL intelligent thermal control fluid, finally realize the non-combustion, high safety and high performance of the battery system level. The ignition of the battery cell displayed at the end of the conference is also very intuitive to reflect the shocking effect brought by the non-burning battery technology compared with the ordinary lithium-ion battery.

　　The two sessions recently pointed out that "new energy vehicles" is a landmark industry in the industrial field of the "new economy". The development of new energy vehicles has once again been promoted to a national strategy. The core factors restricting the development of new energy vehicles today are batteries and charging. Based on the 10-minute fast charge, long-life and non-burning battery technology advocated by Weihong, combined with the Clean Urban Transport (CCT) strategy, it is expected that new energy vehicles will be truly on the fast lane.

　　There are many causes of short circuit in lithium ion batteries, which can be divided into controllable external causes and uncontrollable internal causes. Unstable design, harsh environment, mechanical damage, etc. These reasons can be avoided through electronic devices and mechanical design, but some internal factors cannot be completely avoided.

　　Lithium-ion batteries have the risk of internal short circuit due to the influence of many factors such as the material system and manufacturing process. Although lithium-ion batteries have undergone strict aging and self-discharge screening before leaving the factory, due to process failure and other unpredictable use factors, there is still a certain failure probability that causes internal short-circuits during use. Calculated according to the current industry's highest standard of 18650 battery cell quality control rate of 2ppm, for every 100,000 vehicles sold, 1,600 units have a high risk of spontaneous combustion.

　　For power batteries, there are hundreds or even tens of thousands of lithium-ion batteries in the battery pack, which greatly enlarges the probability of internal short-circuiting in the battery pack. Since the energy contained in the power battery pack is extremely large, the occurrence of internal short circuit can easily induce malignant accidents, causing casualties and property losses. The micro-macro non-combustible battery mainly uses electrolyte, lithium-ion diaphragm and thermal fluid technology to change the defects of lithium batteries, which can avoid the burning of lithium-ion batteries to the maximum extent.

　　non-burning electrolyte

　　Research has shown that when a lithium-ion battery is thermally out of control, it is the electrolyte that emits the most heat. Therefore, not burning the electrolyte is the most important problem to be solved to ensure that the battery does not burn. For this reason, Weihong has re-developed a new type of electrolyte with the goal of non-combustion, fast charging, and long life.

　　In order to verify the performance of Micro Macro's non-burning electrolyte, ignition and heating experiments were carried out respectively.

　　Two actual experiments show that the non-burning electrolyte will not burn like the ordinary solution, which can effectively improve the safety of lithium batteries. Not only that, the non-burning electrolyte also takes into account the two indicators of fast charging and long life.

　　Lithium ion separator

　　With the non-burning electrolyte, another most important component of lithium batteries-diaphragm research, Weihong Power also handed in an answer sheet. Ordinary lithium-ion battery separators usually have a low melting point and will shrink at about 130 degrees Celsius, causing internal short circuits in the battery and thermal runaway. Weihong proposed the idea of using Kevlar materials as the theme to develop high-temperature resistant diaphragms. Compared with ordinary PE separators, the high temperature resistant separators have a higher melting point, which can ensure that the battery will not shrink even at a high temperature of 300 degrees Celsius, preventing internal short circuits in the battery and avoiding thermal runaway.

　　In the face of multiple extreme tests, the micro-macro high temperature resistant diaphragm has won with excellent performance. In the puncture test, even with ordinary electrolyte, it effectively suppresses the occurrence of thermal runaway. In addition, the high temperature resistant membrane must have good wettability, permeability and chemical stability.

　　STL intelligent thermal control fluid technology

　　With non-combustible electrolyte and high temperature resistant diaphragm, it has effectively prevented the problem of active combustion of lithium batteries, but Weihong is not satisfied. To solve the problem of the safety application of lithium batteries, Weihong introduced a unique passive defense measure-STL intelligent thermal control fluid technology.

　　STL intelligent thermal control fluid technology refers to immersing the battery pack in liquid, using insulating heat-conducting liquid as a material with excellent insulation, flame retardancy and thermal conductivity, which can quickly isolate thermal runaway in the case of a small internal short circuit inside the battery pack At the same time, the liquid is used to reduce the temperature of the thermal runaway point, which minimizes the safety risk of the battery pack. As a passive defense system, in addition to safety, STL can also balance the internal temperature difference of the battery pack and use external circulation to achieve better temperature control. At the same time, even if the battery pack leaks, it can be found through liquid detection in time, which is safer. Assure.

　　In order to better reflect the advantages of STL intelligent thermal fluid technology, the same lithium battery was punctured in the air and in the fluid. It can be seen that the STL fluid technology effectively prevents the burning of the lithium battery.