The Influence of High Power Charging on the Lithium Battery Based on Constant and Pulse Current Charging Strategies

摘要

In order to improve the convenience of electric vehicles, the charging power is increasing. However, high-power charging may cause serious and obvious problems in battery heat generation. Therefore, how to make a good balance between fast charging and battery performance maintenance is a hot issue of research. This study is based on a ternary lithiumion battery, through experiments to study the effects of pulse charging and constant current charging on the performance of the battery. An evaluation system based on charging time, rechargeable capacity, temperature change in the charging process and battery life decline during cyclic charging is proposed to evaluate the feasibility of different charging methods as fast charging methods for power batteries. And through the establishment of the temperature rise estimation model, the heat generation and temperature rise during charging are estimated. The results show that compared with the 1C constant current charging method, the charging time using the pulse charging method with an amplitude of 2C and a frequency of 5Hz has increased by 14%, but its chargeable capacity has increased by 12%. When the ambient temperature is 25:°C, the temperature rise of pulse charging mode is higher, reaching 5°C While the temperature rise of 1C constant current charging is 3.5°C The pulse high-power charging mode achieves a better balance in terms of fast charging and reducing battery attenuation.