Hydrogen early warning technology -Lithium - Ion Battery Equipment

The reporter recently learned from Zhengzhou University that Jin Yang, an associate professor at the school’s School of Electrical Engineering, led a research team and found that using hydrogen detection technology can quickly detect the precipitation of trace lithium dendrites on the graphite negative electrode surface of lithium-ion batteries. When the battery energy storage system detects hydrogen gas generation It will immediately cut off the charging power supply to avoid fires and realize early warning of thermal runaway of lithium-ion batteries. The research results were recently published in the international academic journal "Joule".

Lithium-ion batteries have the characteristics of high energy density and have become one of the most competitive energy storage technologies in the fields of portable devices, electric vehicles and large-scale energy storage, and are closely related to people's production and life. However, due to the use of flammable organic solvents as the main components of the electrolyte in existing commercial lithium-ion batteries, and the inherent heat release characteristics of lithium-ion batteries, lithium dendrites will be generated in the case of overcharging or fast charging, which may Puncture the diaphragm, thereby causing safety accidents such as thermal runaway.(Lithium - Ion Battery Equipment)

Through the in-situ optical and gas detection test platform, the researchers found that lithium-ion batteries will generate hydrogen gas in the early stage of overcharging. The hydrogen gas comes from the spontaneous reaction between the metal lithium precipitated on the surface of the graphite negative electrode and the organic binder in the negative electrode. The precipitation of trace lithium dendrites can be detected. In order to further verify the effectiveness of this technology in practical applications, the researchers carried out an overcharge experiment of a lithium-ion battery single module in the actual energy storage cabin. The results show that hydrogen can be detected earlier than other gases, and the detected The time was 639 seconds before the smoke appeared and 769 seconds before the module caught fire. Based on this, the researchers carried out a larger-scale battery cluster overcharge warning experiment, and cut off the charging power supply when hydrogen gas was detected, without any visible smoke or open flames, which verified the safety warning effect of hydrogen gas detection. In view of the frequent occurrence of electric vehicle fire accidents, which pose serious dangers to people's lives and property, it is urgent to find a method that can quickly and effectively detect lithium dendrites and realize early warning of thermal runaway of lithium-ion batteries. The research results are expected to be applied to electric vehicles and large-scale energy storage power stations to prevent the fire hazard of lithium-ion batteries.