TU-TESL

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Nowadays, the topic of "Endurance" is unavoidable for vehicle models. Major new energy main engine manufacturers have launched long-term models. Weima is also one of them. In August this year, Weima's new Ex5 520 was officially launched, and the mileage of NEDC under comprehensive working conditions reached 520 km, while the battery technology is indispensable for the upgrade of endurance. On November 12, Netcom was invited to participate in the Wima battery technology communication meeting to interpret the latest battery technology used in the new Ex5 520 model. Let's unveil its mystery! The single cell is the most basic component in the battery pack system of baopingtai Chemical Co., Ltd., and its energy density is very important. The NCM 811 provided by 520 is used, and the energy density of the cell reaches 280wh / kg. At the same time, Weima has processed the module of the electric core, which makes the electric core become a standard component and easier to produce and develop. In addition, the cell module adopts the full series mode. When the single cell breaks down, the circuit can be cut off quickly, so as to prevent the danger of discharging and heating of the failed cell and fundamentally guarantee the safety of the battery pack. High energy density cell is only the foundation, and temperature is another important factor affecting the performance of battery. We believe that users in the north have deep experience in this, and have their own unique solution for temperature control - battery thermal management system 2.0. Battery thermal management involves two aspects of cooling and heating, in which electric heating and diesel heating systems are used in heating, diesel oil is used for external heating between - 30 ℃ and 0 ℃, and electric heating is used between 0 ℃ and 5 ℃, realizing precise control. On this basis, the thermal management system 2.0 also adds a new winter endurance extension system, which uses external heat sources to heat the battery pack, at the same time, the heat is introduced into the cockpit to reduce the power consumption of the air conditioning, so that the winter endurance is increased by 20%. In terms of cooling, Weima adopts independent liquid cooling design. The liquid cooling circuit is arranged at the bottom of the electric core module, and the aluminum water-cooled plate with high heat conduction is covered with heat-conducting silicone grease. The better fit can improve the heat dissipation performance. It can achieve such precise temperature control, thanks to Weima's built-in two temperature sensors in each cell module, through BMS and BTMS to accurately manage all cells, so that the temperature control error is within ± 2 ℃, effectively improving the battery life. The safety of battery is also the most concerned of users. Weima strengthens the safety of battery pack from the aspects of structure, material and technology. The battery pack box is made of DP780 high-strength steel with multiple stiffeners, and multiple internal buffers are designed to enhance the impact resistance. In the production process, as many as 21 full tests and 2 spot checks, such as air tightness, shall be carried out, and the product can only be offline after 100% of the tests are passed. Weima automobile has designed multiple safety redundancy, and a pressure relief and explosion-proof valve is set at the end of the battery pack. If the temperature of the internal battery module rises and the pressure continues to increase, the pressure relief and explosion-proof valve will start quickly, balance the internal and external pressure differences, and prevent the explosion of the battery pack. Write in the end: with the rapid development of new energy vehicles, the battery / motor / electronic control technology is rapidly upgrading iteratively, in which the battery is the "top priority", which relates to vehicle endurance and safety and other dimensions. Through the technical accumulation in the field of power battery in recent years, Weima has established a more advanced battery technology system, further improved the optimization scheme, and solved the "pain point" of users' car use.