CO Sensors in Containerized Lithium-Ion Battery Storage

The primary role of carbon monoxide (CO) sensors for containerized lithium-ion battery energy storage systems is to sense accurately and provide timely warnings during the initial stages of a battery fire so that effective fire suppression measures can be implemented to prevent the fire from spreading beyond control.

As the global energy crisis continues to deepen, the development of the renewable energy sector has become an inevitable trend. The business of energy storage, as a new sector in the renewable energy sector, has already seen the building of storage stations in certain regions. These stations are of vital significance to enhancing the power grid's capacity to support distributed energy sources, voltage stabilization at the grid endpoints, and serving as reserve power sources in case of grid failure or maintenance. Energy storage stations also have an enormous economic importance in the energy consumption phase of smart grid development, with their safety and stability being essential to the overall economic efficiency of the system.

Containerized lithium-ion battery energy storage systems, a new energy storage equipment, boast high power density, high energy density, long cycle life, high reliability, and good environmental adaptability. They possess extensive application prospects in the power generation side, grid side, and user side. In recent years, 100-megawatt-scale lithium-ion battery energy storage plants have been constructed and commissioned in regions such as Jiangsu, Henan, Hunan, Qinghai, and Fujian. The plants have played an important role in preventing volatility in the output of renewable energy, enhancing the capacity for exporting clean energy, peak shaving of the grid, frequency control, and ancillary services. Large-capacity containerized lithium-ion battery energy storage systems are the future direction of development.

These systems use shared containers to house lithium-ion batteries, battery management systems, monitoring systems, air conditioning systems, fire protection systems, and distribution systems, resulting in highly integrated, large-capacity, and mobile energy storage devices. Although precautions are built into the container design due to the low flash point, high chemical reactivity, and flammability of the electrolytic solvent utilized in lithium-ion batteries, it is challenging to completely eliminate thermal runaway in the energy storage battery due to overcharging, over-discharging, short circuits, or mechanical stress, which would lead to explosions, fires, and other chain reactions. When thermal runaway happens in a set of lithium-ion batteries, it emits high-temperature thermal shock, which affects neighboring batteries, causing thermal runaway to propagate. The reaction emits tremendous amounts of flammable alkane gases, which can cause severe fires or even explosions. Safety accidents in electrochemical energy storage stations have become a routine affair over the last couple of years, resulting in loss of property and lives. The safety issue of energy storage systems for lithium-ion batteries has also become a chief constraint that prevents the industry's accelerated development, and concern from all walks of society keeps increasing.

Moreover, container-type lithium-ion battery energy storage systems consist of many groups of battery cells in parallel configuration. After one lithium-ion battery cell's thermal runaway is triggered, the high temperature of burning and rapid rate of burning make fire extinguishment very difficultly. The combustion performance is significantly different for different lithium-ion battery chemistries and produces enormous toxic and hazardous smoke, with high possibility of explosion during combustion. Once a fire occurs, the following high-temperature burning can lead to full-scale fire or explosion of the entire energy storage system, causing enormous difficulties for firefighting and rescue operations.

As soon as the battery's safety valve opens, excessive quantities of gas and smoke are released, the volume fraction of CO may possibly increase instantly from 2.4×10^-6 up to 190×10^-6. Also, gases such as CO2, CH4, and VOCs have extremely high rises once the safety valve is opened. Therefore, with the relevant gas sensors, smoke detectors, fire detectors, and temperature sensors, and setting up appropriate alarm thresholds according to the thermal runaway behavior of the station batteries, a number of characteristic parameters can be integrated. When the set thresholds for the parameters of different sensors are reached, an alarm is triggered, enabling early warning and detection of lithium-ion battery fires, and allowing corresponding control measures to be implemented to prevent further progression.

In addition, it is important to select the proper sensors and detectors based on their range and sensitivity and to calibrate redundant systems to ensure efficient response of the early fire warning and detection devices at the station.

• energy storage systems