Reveal the byd power battery core technology

As one of the most core components of pure electric vehicles, power battery for the vehicle's range, curb weight, dynamic performance and handling performance. In the manufacturing cost of pure electric vehicles, battery has the highest proportion also, generally over 30%, this led to the electric car late higher price and maintenance costs. Therefore, reduce the unit cost of the battery, and increase the energy density of battery, has been the main development direction of electric vehicle technology.

for byd was started with the battery, high performance battery is one of the killer of byd. Especially in replacing the higher energy density, higher discharge voltage, low temperature performance better ternary lithium batteries, byd EV model series of core competitive ability is greatly increased.

this content, we will for byd qin Pro EV500 models of battery pack to conduct a comprehensive and dismantling, and parses the byd have battery pack safety design, thermal management design innovation and technology management.

in uncovered the ultrathin nonmetallic cover of the battery pack, and silica aerogel fireproof heat insulation layer, we can see clearly the whole battery pack structure, one of the most visible is the integration technology of the battery pack. Integration process in the development of power battery is very important, must meet the mechanical protection, thermal protection, thermal management, environmental protection, and all aspects of safety requirements under the premise of the pursuit of lightweight and optimize cost

and tesla adopted by the cylindrical batteries in a different way, byd has adopted domestic penetration rate higher square aluminum shell, with high energy density, low integration difficult. In addition, the square of the encapsulation process, also is helpful to narrowing the gap between the batteries, let whole size is more compact, and cylindrical batteries must set aside of the triangle gap between the batteries, reduces the space utilization.

magnesium aluminum alloy shell material to build batteries, compared with the cylindrical battery USES the stainless steel shell, lighter, cheaper, to improve the energy density of batteries, but also lower the manufacturing cost. And side shell structure can accommodate more expansion stress of electrolyte, batteries sheet was lower, the battery life is longer than cylindrical 2 times more than the

the qin Pro EV500 byd is adopted independent research and development of nickel cobalt manganese battery three yuan, which is based on cobalt acid lithium, improved, in nickel cobalt manganese battery cathode material, and the reasonable ratio of the percentage of nickel cobalt manganese. In optimizing cost, ensure safety at the same time, makes the battery with high capacity, good thermal stability as well as wide, charge and discharge pressure excellent electrochemical performance.

and effectively improve the battery energy density, 160. 9 wh/kg, in combination with 56. The capacity of 4 KWH. Realize the NEDC range of 420 km, 60 km/h speed range of 500 km, thus effectively alleviate the user in the range of concerns. And thanks to high energy density battery, effectively reduce the car battery load, so as to reduce the weight of car.

the battery module of burst mode fully takes into consideration the requirements of heat and light, using short on both sides of the aluminum plate and elastic steel strapping, adaptive battery in the process of charging and discharging. At the same time a variety of specifications of the module can realize the flexible layout, adapt to the needs of different models. As far as possible in the central body flat, single layout, increase the height space inside the car.

in the detailed design, the primary loop connection and its signal acquisition part USES the aluminum bar, conductive ability under the same condition, compared weight using copper can be reduced by more than half, and the cost can be controlled.

but we found that the copper platoon is adopted instead of LvPai on leads to extremely, this is because LvPai hardness is low, in the case of high temperature, high stress, aluminum collapse will happen, and not easy to rebound after collapsing, a fever a cold will cause gap increased, increased contact resistance, bring safe hidden trouble.

and on the connection of copper aluminum different material, byd has adopted a called electromagnetic pulse welding technology. Relative to the now commonly used copper aluminum rolling connection directly or ultrasonic welding technology, electromagnetic pulse welding process difficulty is bigger, although the cost will also increase, but the effect is best, is currently the more advanced technology.

in each battery between column and column, and also the aluminum bus bar and a column with laser welded together, guarantee the reliability. And a depression is designed on the bus, used for mechanical vibration and shock absorption expansion caused by stress. And if it is straight aluminum bar, as the battery aging, adjacent batteries column spacing increases, the tensile stress will affect the reliability of solder joints.

in the part of signal connection, byd has adopted the flexible circuit board, the wire and compared with the traditional sampling plan, more integrated, and more thin. If you look carefully, you will find the flexible circuit board with filamentous wiring, we call it a sampling line fuse line. It is used in the collision, may cause short circuit, sampling wire extrusion resulting in sample line of fire, these filaments will due to overcurrent fusing when short circuit, so as to cut off the short circuit loop, the wire and ensure the safety and the safety of the battery module.