On June 28, the Great Wall Motor(GWM) of China announced that it has succeeded in developing the “Dayu Battery”, which is a highly safe power system for electric vehicles. The Dayu Battery realized no fire and no explosion in the case of thermal runaway. As the content of nickel, cobalt and manganese in the anode material is 80%:10%:10%, the energy density of this high nickel battery is increased by 50%. On the other hand, the increase in nickel content will cause the stability of the anode material become worse, and increase the risk of spontaneous combustion when thermal runaway occurs. Therefore, the GWM adopted a new design philosophy to improve the safety of the Dayu Battery.
According to a related report, to increase the safety of Dayu Battery, the following new design philosophies have been adopted.
- Heat source isolation: The company’s newly developed double-layer composite material is adopted among battery cells.
- Two-way commutation: A large number of high-temperature and high-pressure gas and fire flows will generate during the thermal runaway process, two-way commutation can help heat source achieve safe flow in the battery pack, and reduce the thermal impact of the heat source on the adjacent modules, which can avoid the secondary ignition.
- Heat flow distribution: Through application research such as combustion model, thermophysics, impact strength and pressure calculation, the uniform distribution of gas and fire flow in the variety of structural channels can be realized.
- Directional eliminate explosion: Combining the position of the explosion-proof valve of the battery, design the fire flow for thermal runaway, and guide the fire source to the fire extinguishing channel quickly and discharge safely through flow dividing, guiding and two-way commutation.
- High-temperature insulation: Take high-temperature insulation protection for high-voltage connections and high-voltage safety areas to eliminate the danger of high-voltage arcing.
- Automatic fire extinguishing: A multi-layer asymmetric honeycomb channel is arranged at the directional explosion discharge outlet, which can keep the pressure inside the pack higher than outside, and avoid secondary ignition caused by the entry of oxygen.
- Smart cooling: When the battery management system recognizes that the battery cell has triggered a thermal runaway, through BMS and the cloud dual monitoring, the entire vehicle can quickly turn on the cooling system and inhibit the thermal diffusion of the battery.
The GWM announced that the Dayu Battery will be installed in the model which will be launched in 2022. In addition, the domestic sales of GWM passenger cars in 2018 ranked second among Chinese domestic automobile manufacturers.
For the original text of the above news, please refer to the following URL (in simplified Chinese).
The news on the homepage of GWM
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