Chinese researchers were able to develop an innovative sodium battery that combats thermal breakdown – one of the most serious challenges facing batteries – by forming what is known as a “smart firewall” inside the battery itself.
A research team from the Chinese Academy of Sciences, led by Professor Yong-Sheng Hu from the Institute of Physics, who specializes in developing advanced materials for sodium and lithium batteries, has led efforts to develop a self-protecting, non-flammable electrolyte solution that prevents thermal breakdown from occurring inside the battery.
It should be noted that thermal breakdown occurs when the temperature of the battery exceeds its cooling capacity, which leads to a rapid rise in temperature exceeding 20 degrees Celsius per minute, which may cause the emission of gases, the outbreak of fires, or even explosions.
The new technology is based on the use of a polymerizable electrolyte, which turns into a solid inner layer when the temperature reaches 150 degrees Celsius, which forms a barrier that prevents heat transfer and stops the chain reaction before it escalates into a catastrophic failure. That is, the battery automatically builds an “internal firewall” when needed.
Tests conducted on a cylindrical cell with a capacity of 3.5 ampere-hours revealed the battery’s ability to completely resist thermal collapse, even under nail penetration tests. The battery remained stable at temperatures up to 300 degrees Celsius, without any smoke, fire, or explosion appearing.
The researchers confirmed that these safety improvements did not negatively affect the performance of the battery, which achieves an energy density of up to 211 watt-hours per kilogram, and operates efficiently within a wide range of temperatures ranging from -40 to 60 degrees Celsius, while maintaining its stability at voltages exceeding 4.3 volts.
The team explained that this achievement will contribute to accelerating the adoption of sodium batteries in sectors where safety is of utmost importance, such as electric cars, heavy trucks, and large-scale energy storage systems, especially in China.
