What are the basic requirements for the structural design of the battery system?
Reply：The battery system is an integration of machinery and electricity. Especially when the electric vehicle battery system is installed on the car, it encounters a series of problems such as ground excitation and a large amount of heat generated by the battery during charging and discharging. Therefore, in the mechanical structure of pure electric vehicles The following principles must be met during the design process:
(1) Good insulation: The output battery of the electric vehicle battery box is generally 120V, which is much higher than the safe voltage of the human body. Therefore, the battery pack and the battery box, the battery box and the car should be fully considered in the design process. Insulation problems.
(2) Vibration damping and anti-collision ability: The car is driving on bumpy roads, so that the fixing of the battery module in the battery box and the fixing of the battery box on the car should meet the requirements of car vibration, rollover and collision avoidance. basic requirements.
(3) Good heat dissipation capacity: The battery will generate a lot of heat during the discharge process. The design of the battery box not only meets the requirements of restraining the temperature rise of the battery box, but also should make the temperature difference within the battery box smaller.
(4) Good waterproof and dustproof ability: the battery box has a certain waterproof and dustproof ability.
(5) Satisfy the installation conditions of the entire vehicle: The maximum shape of the battery should meet the requirements of the installation of the entire vehicle.
After meeting the above mechanical design requirements, the battery system must fully consider the final specific energy design. The specific energy of commercial battery cells can be as high as 40w.h/kg, but after the battery cells are connected in series and parallel to form a battery system, their specific energy will drop rapidly. Therefore, the specific energy should be used as one of the optimization parameters of the battery system during the design process. the goal. Refer to Tesla Model S, the mass of the entire battery system is 450kg, and the specific energy is as high as 120w.h/kg. A certain battery pack designed by EnerDel is assembled from high-energy laminated pouched batteries with a specific energy of 150w.h/kg, and finally The specific energy of the battery pack level is about 90w.h/kg. After Mitsubishi iMiEV connects 88 lithium-ion battery cells in series to form a battery pack, the specific energy of the battery pack is 82W.h/kg. In summary, in this section, the specific energy target of the battery system is designed as 95w.h/kg