'Cellular' battery re-meaning electric car safety
At present, based on the circular 21700 ternary battery and the development and application of potting glue, the 'honeycomb' battery has broken through the ternary heat loss safety with an energy density of 240wh/kg, and is exploring the energy density of 255Wh/kg. The safety of thermal runaway is the core proposition that must be solved in the current industrialization of high specific energy batteries and long-range electric vehicles. Since the heating of a single cell cannot be completely eliminated, once the thermal runaway of the cell occurs, how to solve the safety problems of the battery pack and the entire vehicle? A barrier in front of car companies and battery companies. On June 10th, the 13th High-Tech Lithium Battery Industry Summit hosted by High-Tech Lithium Battery and High-Tech Industrial Research Institute was grandly held. This summit was named by President Li Yuanheng and the theme was 'Market Segmentation and Industrial Fission'. The site exceeded 700 Senior executives of the company jointly conducted in-depth discussions on the trends and changes in the power lithium-ion battery industry in 2020. In the opening session of the title of Sikeqi, Qin Liwei, technical director of the battery system department of JAC New Energy, delivered a keynote speech on 'Cellular Battery-Re-meaning Electric Vehicle Safety'. The structural principle of the honeycomb battery is based on the bionic design of the honeycomb structure. All the cells in the battery pack are 360° covered with lightweight self-leveling thermal conductive glue to achieve unitized management. Qin Liwei said that in ten years, JAC has chosen the circular battery technology route, and the honeycomb battery technology has gone through three stages of mechanism exploration, iterative development, and technology solidification. At present, based on the circular 21700 ternary battery and the development and application of potting glue, the 'honeycomb' battery has broken through the ternary heat loss safety with an energy density of 240wh/kg, and is exploring the energy density of 255Wh/kg. At the same time, based on cylindrical batteries, JAC has also established a five-level battery thermal runaway safety development process to ensure the comprehensive development of thermal runaway safety from the levels of cells, modules, simple battery packs, battery packs, and vehicles. 'Nearly 10,000 battery cell explosion tests have verified that the honeycomb battery safety technology can achieve a battery cell explosion, and the battery pack will not fire or explode.' Qin Liwei emphasized that the actual vehicle has also demonstrated the effectiveness of the 'cellular' battery thermal runaway safety technology. Assure. As of April 2020, 60 million round batteries have been used for four years, and a total of 6 cases of battery explosion failure vehicles have been monitored and identified, and the safety issues caused by the continued use of failed batteries have been dealt with in a timely manner. The actual vehicle has demonstrated 'cellular' batteries. Thermal runaway safety technology can effectively solve the safety problem of battery thermal runaway and re-meaning the safety of electric vehicles. Based on the circular battery, a five-level battery thermal runaway safety development process has been established to ensure the comprehensiveness of the thermal runaway safety development. The first level: battery cells, JAC's joint suppliers design the battery shell material, thickness, positive and negative explosion-proof pressures, and the stretching process control of the shell production to realize the directional blasting of the battery cell and eliminate the side blasting and the shell. Local melting hole. The second level: modules, through the module electrical isolation and thermal isolation methods to achieve a single battery cell explosion after the energy release control; third level: simple battery pack, through the module protection, battery pack exhaust path design, to achieve relative Adjacent modules are safely isolated; the fourth level: the battery pack, through the integrated high-strength battery shell and bottom protection design of the body, to ensure that the battery pack structure is safe and reliable under extreme conditions; the fifth level: the entire vehicle, through The vehicle integrated thermal management system design, vehicle control system design, real-time monitoring of the safety status of the battery pack, the cooling system can be turned on immediately after the battery pack explodes to reduce the temperature of the battery pack. At the same time, the battery failure is reported to the remote monitoring system, so as not to cause the entire vehicle to catch fire, and to ensure the absolute safety of the vehicle and personnel. Qin Liwei believes that the cylindrical cell + honeycomb battery technology method can achieve high safety and high endurance for high specific energy ternary battery electric vehicles. Recently, three mandatory national standards for electric vehicles have been officially announced. In particular, the 'Safety Requirements for Power Batteries for Electric Vehicles' standard has added relevant requirements for battery system heat dissipation. JAC also completed the thermal runaway safety verification of the newly launched iEVA50, iC5 and iEV6E battery packs for the three electric vehicles launched in 2020 within two weeks of the announcement of the new national standard. All of them have achieved an explosion of a battery cell, and the battery module will not have thermal diffusion. The battery pack is not out of control.
