Charging mode of electric vehicle lithium battery

At present, the construction progress of electric vehicle charging facilities has seriously affected the large-scale promotion and application of electric vehicles in China. Based on the analysis and research of electric vehicle charging mode and household distributed energy storage mode at home and abroad, this paper proposes a technical solution that can effectively alleviate and solve the difficulty of charging electric vehicles.

The electric vehicle power battery is mainly composed of lithium batteries , and has three modes of normal charging, fast charging and rapid battery pack replacement.

Electric vehicle charging

1) Regular charging (slow charging) mode.

Charging the vehicle with ordinary AC power is the most common charging method for electric vehicles. The current and power are low when charging. The charging time is generally 5~8h, which has little impact on battery life and grid impact. The time period is charging the vehicle to reduce the cost of electricity. However, due to the long time required for charging, it is necessary to configure a charger with AC/DC conversion function. It takes a long time to occupy a parking space during the charging process. When the vehicle has emergency power replenishment demand, it is difficult to meet the needs of the owner.

2) Fast (emergency) charging mode.

The DC charging pile is used to quickly charge the vehicle with a large current, and the battery storage capacity can reach 80% or more within 10 to 15 minutes. The charging pile generally needs to be set in the charging station, and the alternating current of the power grid is converted into direct current by the current converting device in the charging station system to charge the electric vehicle. High charging voltage "current is large, usually can reach several times or even ten times of the normal charging current, and the charging time is relatively short. Fast charging will reduce the cycle life of the power battery. When the vehicle is charged centrally, the power grid has a certain impact. Vehicles usually need to be recharged at a nearby charging station, which can be used as a supplement to conventional charging methods.

3) Power change mode.

Replace the battery pack with exhausted energy directly with a fully charged battery pack. The time required to replace the battery pack is 5 to 10 minutes. To a certain extent, it can make up for the shortcomings of electric vehicles charging time. Power batteries can usually be leased to reduce the initial cost of purchasing an electric car. The replaced power battery has ample time for maintenance, and can be concentrated in the low valley charging period, which has certain positive significance for improving the cycle life of the battery. "Because of the different specifications and sizes of various electric vehicles, the use is different. There are many differences in design, it is difficult to standardize and generalize the "series" of the power battery pack. The power exchange mode requires the construction of a standard power station, and a large number of spare batteries need to be prepared, and there is a large demand for land. "The long construction period of the station" has a large capital investment. This mode is only suitable for certain specific models that are used in specific line sections and the application range will be very limited.

This paper analyzes the three charging modes of electric vehicle batteries, and analyzes the advantages and disadvantages of each mode. Finally, there is no perfect solution for the charging method of electric vehicles. I hope that lithium batteries will be used in the next few years. The technology has made a breakthrough.

The page contains the contents of the machine translation.