The battery of an electric car catches fire and explodes, which is one of the most worried accidents for all electric car owners. However, if there is a battery and the official promises that it will never fire or explode, what would you think? Some time ago,Great Wall Motors officially released the “Dayu Battery Technology”, which will be fully applied in 2022 and will be installed on the first model of the Salon brand for the first time.
According to the official, Dayu battery can achieve full coverage of the cell chemistry system, ensuring that the battery pack does not catch fire or explode if a single or multiple cells at any position trigger a thermal runaway.
A few days ago, the Great Wall Motors official explained the core technical principles of Dayu battery in detail on its official platform. Through a picture, it explained why this battery can never explode.
It is the same as the principle of “Dayu’s water control, turning blockage into dredging” Dayu battery technology independently develops 8 new design concepts with “control + conduction = connection” as the underlying logic.
Heat source isolation: double-layer composite materials are used between the cells to isolate the heat source and can withstand flame impact; two-way commutating: two-way commutating to realize the safe flow of high temperature and high pressure gas and fire in the battery pack, reducing the impact of heat sources on adjacent modules and avoiding Second ignition.
Heat flow distribution: Through application research such as combustion model, thermofluid mechanics, impact strength and pressure calculation, the uniform distribution of gas and fire flow in a variety of structural channels can be realized to avoid heat flow concentration;
Directional explosion discharge, high temperature insulation: combined with the position of the explosion-proof valve of the battery,Design the gas and fire flow path after thermal runaway, divert and divert the fire source, bidirectionally commutate, and quickly guide it to the fire extinguishing channel and discharge it safely.High-temperature insulation protects high-voltage connections and high-voltage safety areas, eliminating the danger of high-voltage arcing;
Automatic fire extinguishing, positive pressure oxygen resistance: Multi-layer asymmetric honeycomb channels are set at the directional explosion discharge outlet to keep the pressure inside the bag always higher than the outside of the bag to prevent oxygen from entering and causing secondary combustion;
Intelligent cooling: The battery management system effectively recognizes that the battery cell has triggered a thermal runaway. Under the dual monitoring of BMS and the cloud, the vehicle quickly turns on the cooling system and suppresses the thermal diffusion of the battery.
The Great Wall official said: They carried out the most rigorous testing and verification in the industry for Dayu Battery, selecting the most challenging ternary 811 system high-nickel high-capacity battery cell in the industry, and testing the middle two cells of the module. Carry out heating test, which is also the most stringent test method in the world.
During the test, the accumulation of multiple battery cells occurred three times in a row to trigger thermal runaway. The temperature reached a maximum of 1037°C. The air pressure in the battery pack reached three peaks, and the instantaneous maximum air pressure was about 16kPa.Through the fire extinguishing system, the maximum temperature of the smoke overflowing from the battery pack is suppressed to be lower than 100 ℃, so as to avoid secondary damage to the surroundings.
At the same time, Great Wall Motor believes that the overall progress and safety of the battery industry are the choice to maximize benefits. Great Wall will regard Dayu battery as an open patent, which will be freely open to the whole society, and the whole industry will share the benefits of battery technology advancement.
