Energy storage refers to the process of storing energy through a medium or equipment and releasing it when needed. Among them, lithium-ion batteries have become the main force of electrochemical energy storage due to their advantages of long cycle life, high working voltage, high energy density, and small self-discharge.
Strictly speaking, energy storage itself is not an emerging technology, but from an industrial point of view, it is in the initial and development stage.
Throughout recent years, the rapid development of the energy storage industry in mainland China also contains huge risks. According to incomplete statistics, in the past ten years, there have been more than 30 safety accidents of electrochemical energy storage power stations around the world, most of which occurred in the past five years, and the safety situation of electrochemical energy storage is not optimistic.
Although there are many reasons for the fire of energy storage power stations, the thermal runaway of the battery itself, as well as the thermal runaway spread of battery modules and systems, is the current focus of the industry.
Gas escape is one of the main manifestations of runaway lithium-ion batteries. When a lithium-ion battery catches fire, it will rapidly emit a large amount of white smoke, the main component of which is the vapor or decomposition products of the lithium battery electrolyte. In the early stages of a fire, the difference in smoke color is one of the most obvious features that distinguish lithium battery fires from common fires.
After the thermal runaway of the lithium-ion battery, the decomposed combustible gas is mixed with air to form an explosive mixed gas, and the high-temperature particles ejected by the lithium battery will deflagrate in the local space, resulting in the initial stage of the fire often accompanied by an explosion sound. The electrolyte itself is a flammable solvent and is extremely flammable, which is the reason why lithium batteries will develop rapidly after fire, and at the same time, the battery decomposes to produce combustible gas (mostly H2 and CO), which will also aggravate combustion.
At present, there is no technical method that can ensure that the lithium battery does not have thermal runaway, and there is only a method that can detect and prevent the thermal runaway of the lithium battery in time. We can use gas sensor technology to set the corresponding early warning threshold according to the thermal runaway characteristics of the energy storage battery, so as to achieve early detection and early warning and prevent the battery fire from further expanding.
Lithium batteries have the characteristics of high energy density, light weight and high conversion efficiency, but they are also limited by flammable and explosive conditions such as poor cycle life. When the battery is overcharged, overdischarged, overheated, mechanical collision and other internal and external factors, it is easy to cause the collapse of the battery separator and internal short circuit, resulting in thermal runaway. If thermal runaway propagates within the battery module, it can lead to a fire accident in the system.
Thermal runaway is different from ignition, lithium batteries can completely occur in the absence of open flame and oxygen support, and gas escape is one of the main manifestations of lithium-ion battery runaway. According to the thermal runaway characteristics of energy storage batteries, we can set the corresponding early warning thresholds through gas sensor technology to achieve early detection and early warning to prevent battery fires from further expanding.
In view of the thermal runaway of energy storage batteries, it is necessary to adhere to the principle of "early detection and early disposal", and carry out advanced detection and early warning of the thermal runaway of lithium batteries in the energy storage cabin, so as to extinguish fire hazards in the embryonic stage. As a professional sensor solution provider, Huiwen Technology can provide a variety of sensors and overall sensor solutions such as smoke sensor modules, MEMS combustible gas sensors, carbon monoxide sensors, battery safety detection modules, electrochemical modules, etc. for energy storage safety monitoring.
Gas alarm monitoring equipment and systems are installed in each area of the relevant project site, and the monitored data is centrally managed and monitored. It can grasp the dynamic information of gas leakage in each area in time, so that the safety management personnel can fully understand the dynamics of gas leakage in each area in a timely manner, and take corresponding measures in time to achieve the purpose of controlling the on-site ambient gas concentration within the safe range.