Guchen Product Developed to Manage Thermal Propagation in EV Lithium-ion Battery

The EV lithium-ion battery is a complex system that requires careful design to ensure safe operation and long service life. One of the most critical issues for the design of this system is thermal management. The battery must be able to withstand high temperatures during charging and discharging processes, in order to prevent overheating and fire. In addition, the battery can experience thermal runaway, which is the rapid increase in temperature caused by an internal short circuit or spontaneous chemical reaction. If this occurs, the battery can catch fire and release toxic gases that have been stored inside.
To address these issues, Guchen Electronic developed a nitrogen fire protection device (NFPD) for EV lithium-ion batteries that uses nitrogen gas to hinder any possible ignition source inside the battery compartment, thus to prevent battery fires.
 

Principle of NFPD

Guchen's lithium-ion battery box nitrogen protection device uses high-purity nitrogen pre-intervention to continuously maintain a low-oxygen flame-retardant environment in the battery box. The real-time production of nitrogen comes from the air, and the acquisition of flame-retardant raw materials is not limited by time and location. More importantly, the nitrogen concentration is as high as over 99%, which can fully meet the concentration threshold requirements of the inert gas in the battery box.
 

Functions

The EV lithium-ion battery fire protection and thermal runaway prevention
The device can effectively control thermal runaway by continuously injecting the N2 gas into the battery compartment, which will isolate the oxygen from the EV battery cells.

Characteristics of NFPD

◆ State-of-art concept

After more than two years of basic research and relying on a large amount of test data, Guchen created and improved the escape curve of nitrogen under the IP67 protection level by testing the fluid movement process and protection effect of nitrogen at different flows and concentrations in the battery box. The fluid simulation model was developed and the nitrogen concentration problem was successfully solved. After more than a year of continuous testing, including the trial assembly of Yutong bus prototype, under roughly the same temperature conditions, the concentration and flow rate of nitrogen showed almost no attenuation, and the concentration could still be maintained above 99%.
 

◆ Monitoring, real-time data transmission

In order to better improve the accuracy of the system, Guchen combined his many years of thermal runaway monitoring and early warning experience and relied on the data accumulated in several years of experiments to successfully develop a high-precision pressure detector to achieve all-round dynamic monitoring of the sealed state of the battery box. At the same time, the system also has functions such as remote diagnosis, remote configuration, and time calibration, which improves the reliability of the system.
   

Scope of Applications

Guchen's lithium-ion battery nitrogen protection system can cover lithium battery application scenarios such as commercial vehicles, heavy trucks, underground mining trucks, energy storage power stations, battery swap stations, etc. Guchen has established different control logics for different scenarios. For example, for urban buses or engineering vehicles that frequently initiate flameout and power outages, we have designed a power outage memory function. In the event of a sudden power outage, the various operating states of the system can be Instant memory lock and more.