As the core component of electric vehicle (EV) and hybrid electric vehicle (EV), power battery directly affects the performance, endurance and safety of the vehicle. With the rapid development of new energy vehicle market, the dual demand of economy and environmental protection has become increasingly prominent, and the design and testing standards of power batteries have gradually become stricter. This paper will provide references for practitioners in related fields on the basis of analyzing the design requirements, testing priorities and engineering applications of power batteries.

I. Power battery design requirements

1. Energy density and power density

the energy density (Wh/kg) and power density (W/kg) of power battery are important indexes to evaluate its performance. The energy density determines the amount of electricity that the battery can store per unit weight, which directly affects the endurance of the vehicle; While the power density affects the power output capacity of the battery during acceleration. The balance between these two indicators should be achieved during the design to ensure the performance of the battery under different working conditions.

2. Cycle life and charge and discharge efficiency

cycle Life is the performance retention ability of power battery after multiple charge and discharge, which is usually expressed by the number of charge and discharge cycles. The design should ensure that the cycle life of the battery is not less than 1,000 times while the battery is highly charged. Charging and discharging efficiency (I .e. energy loss during charging and effective energy output during discharging) should also be improved as much as possible to reduce energy loss.

3. Thermal management and safety

power batteries generate heat during use, so efficient thermal management system design is very important. The battery design must take into account the heat dissipation performance to prevent potential safety hazards caused by overheating. At the same time, the safety design of the battery should conform to national and industry standards, including short circuit prevention, impact resistance, puncture resistance and other functions to ensure safe operation in various environments.

4. Structural design and material selection

the structural design of the battery should give consideration to light weight and strength. Selecting high strength but light weight materials can effectively reduce the burden on the system. At the same time, the monomer design inside the battery also needs to consider the ease of production and assembly to improve the production efficiency.

II. Key points of testing

1. Performance test

the performance test includes battery capacity test, charge-discharge efficiency test, energy density and power density test. Verify the battery performance under different working conditions (such as high and low temperature, fast charging, continuous discharge, etc.) to confirm whether it meets the design requirements.

2. Cycle life test