Lithium battery thermal runaway problem has caused concern in the energy storage industry

'Safety issues are one of the obstacles to the large-scale application of energy storage batteries, and most of the safety issues are caused by the thermal runaway of lithium batteries.' A few days ago, 'Focus on Energy Storage Safety and Escort Industry Development' held in Hefei. On the theme forum, the participating experts pointed out the nature of lithium battery safety problems sharply. ■Energy storage faces the challenge of 'thermal runaway\'For example, internal diaphragm breakage, external wire short circuit and electrical fire can cause internal or external short circuit of lithium battery. A large amount of heat accumulates inside the battery in a short time, causing the positive and negative active materials and electrolyte to decompose, causing the battery to catch fire. Or an explosion will cause a chain of thermal runaway of adjacent batteries, the spread of the accident, and the thermal runaway of the energy storage system.' Jiang Weiliang said. Duan Qiangling, an associate professor at the University of Science and Technology of my country, believes that lithium batteries are composed of positive electrode, negative electrode, electrolyte and other materials, and they are capable of intercalating and dragging out the release of lithium ions during use. Once there are unstable factors in the use of lithium batteries, such as overcharging, high temperature, collisions, etc., it may induce thermochemical reactions inside the battery, leading to thermal runaway. ■Explosion accidents or destruction industries Compared with the safety issues of power lithium batteries used in electric vehicles, the safety of energy storage lithium batteries has received less attention from the general public. In fact, the frequent occurrence of energy storage safety accidents in recent years has affected investors' confidence in the energy storage industry. According to analysis, when the battery is thermally out of control, it will emit a mixture of high-temperature gases and particles. These gases are flammable and are extremely prone to fire. The high-temperature ejection and the flame of the ejection burning will heat the surrounding battery, which is likely to cause a large Explosion accident. Once an explosion accident occurs, it will be a devastating blow to the industry. Jiang Weiliang said that the occurrence of energy storage system thermal runaway safety accidents will have a certain negative impact on the energy storage projects under construction and proposed construction, as well as investment and financing channels. “Stakeholders of energy storage projects are not only worried about the loss of energy storage assets, but also about safety risks to surrounding facilities, and even more worried about personal safety accidents, which will affect their confidence in investing in energy storage projects and hinder the sustainable development of the entire energy storage industry. 'According to the reporter, the current research on the prevention of thermal runaway of energy storage batteries is mainly focused on the amount of energy released, the rate of energy release, and how to prevent thermal diffusion. ■Realize prevention from the technical source. Experts in the industry said that to solve the problem of thermal runaway, it is necessary to suppress side reactions, reduce heat generation, improve heat dissipation capabilities, and prevent thermal diffusion. Duan Qiangling pointed out that the propagation mode of thermal runaway in the module is thermal radiation, thermal conduction and thermal convection. He proposed to suppress the spread of thermal runaway in the battery module, improve the heat dissipation efficiency of the battery pack, reduce the heat transfer capacity between the batteries, and at the same time increase the battery spacing, add heat insulation layers, and take timely measures to suppress fire extinguishing. Professor Wang Zhirong of Nanjing University of Technology believes that it is necessary to set up an over-temperature protection device to perform different alarm prompts and protection actions when the temperature is too high. 'According to the actual situation of the energy storage battery, cooling methods such as air cooling, liquid cooling and phase change materials should be selected to make the battery work in a stable temperature range, and different temperature thresholds can be set according to the situation to monitor the temperature of the energy storage battery in real time. When the monitored temperature reaches a certain threshold, the corresponding heat dissipation measures will be activated.” Jiang Weiliang said that in the long run, it is necessary to break through the safety bottleneck of the cell through the advancement of cell technology and achieve the goal of intrinsic safety. At this stage, in the selection of batteries, batteries with good safety and reliable quality should be used as much as possible. 'At the same time, it is necessary to strengthen the construction of safety standards and testing and certification, adopt mandatory testing and certification to improve the safety level of energy storage products, improve the level of operation and maintenance, and achieve early detection and early elimination of potential safety hazards to prevent safety accidents.' Li Li The battery thermal runaway problem has caused concern (attention) in the energy storage industry. Statement: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete the previous article: Comparison and analysis of the performance of lithium iron phosphate batteries and ternary power lithium batteries