Analysis of the causes of explosion accidents in energy storage power stations. It is recommended to do online monitoring and detection of battery data

On April 16, 2021, an explosion and fire accident occurred at an energy storage power station in Fengtai District, Beijing, resulting in the death of two firefighters, one firefighter was injured, and one employee of the power station lost contact. The cause of the accident is still under investigation. Many people have questions about why an explosion and fire accident occurred in an energy storage power station? Spontaneous combustion of lithium-ion batteries is a well-known thing. Why do explosions that cause deaths occur? In this regard, relevant industry experts said that there is indeed a possibility of explosion in energy storage power stations. There are batches of energy storage batteries in energy storage power stations. At present, most energy storage batteries use lithium-ion batteries, whose cost performance and energy density are more advantageous than other batteries. However, lithium-ion batteries are prone to short-circuit inside the battery and cause spontaneous combustion. A battery is composed of a positive electrode and a negative electrode. The inside of the battery is insulated between the positive and negative electrodes through a separator, and the electrolyte plays the role of conducting lithium ions. If the diaphragm is damaged, the positive and negative electrodes will be short-circuited, and heat will continue to be released. The heat accumulation will aggravate and decompose all the internal structures of the battery, release more heat, and finally lead to spontaneous combustion. The spontaneous combustion of a battery will spread the heat to the surrounding batteries. Ten, ten pass one hundred. The electrolyte itself is a flammable solvent and is extremely flammable. This is the reason why lithium-ion batteries will develop rapidly after a fire. At the same time, the decomposition of the battery and the formation of combustible gas and oxygen will also intensify the combustion. There are roughly the following reasons for the short circuit in the battery: 1. As the battery ages, lithium from the negative electrode of the battery forms dendrites and grows continuously, piercing the diaphragm. 2. Diaphragm has production quality problems. There are defects when leaving the factory. Dust or burrs of the positive and negative electrodes during the production process will cause internal short circuits. 3. The high temperature of the battery during use will cause the diaphragm to decompose and melt. 4. Other external factors, transportation vibration, collision, puncture, etc. The explosion of the energy storage station should be the occurrence of combustible gas after the battery spontaneously ignites. The combustible gas cannot be released in the energy storage container. After the concentration reaches the explosive limit, the entire container will explode, which is powerful enough to cause casualties. To put it simply, a lithium-ion battery is an electrical product, and it will catch fire if a short circuit occurs. There are many flammable materials in the lithium-ion battery, and the fire will be very violent, and flammable gas will also appear. The energy storage container is a sealed box. A large number of lithium-ion batteries are stored in this box. After the combustible gas from the spontaneous combustion of the battery is full, the entire box may explode, just like an empty oil tank encountering a spark explosion. At present, the industry also has related standards for energy storage fire safety 'GB/T50148-2014 Design Code for Chemical Energy Storage Power Stations'. The important content is the electrical safety and fire protection configuration of energy storage power stations. The fire safety monitoring is still based on traditional fire smoke alarms and temperature alarms, which are post-accident alarms. The internal short circuit of the battery can be used for early warning through abnormal changes in battery voltage, temperature and other indicators to stop the loss in time, or early warning to solve the early micro-faults that caused the internal short circuit, so as to prevent problems from being 'burned'. It is recommended that energy storage power stations do online monitoring and detection of battery data to prevent accidents and reduce the occurrence of tragedies similar to Fengtai energy storage stations.