Research on Lithium-Ion Battery with New Flexible Electrode Materials

Abstract

The thesis studied the thermal characteristics and influencing factors of the flexible electrode material lithium-ion power battery during the charging and discharging process through a combination of experiment and simulation. Studies have shown that the charge and discharge rate, ambient temperature, and state of charge will affect the battery’s thermal characteristics. The greater the charge-discharge rate, the lower the environment, and the lower the state of charge, the greater the battery’s healing power. The higher the temperature rise of the battery. As the discharge rate increases, the proportion of ohmic heat in the total heat increases, and the proportion of polarization heat and reaction heat in the total heat decreases: In the case of high-rate discharge, ohmic heat and polarization heat play a major role: environment the lower the temperature, the greater the total internal resistance of the battery, so that the greater the healing power of the battery, the faster the temperature rise of the battery. Besides, the paper proposes an internal heat source model suitable for lithium-ion batteries. The simulation results show that the proposed model can better reflect the battery’s internal temperature field during the discharge process. Simultaneously, the model is used to simulate the temperature rise of the battery when the battery is working under harsh conditions and the influence of different convective heat transfer coefficients on the battery’s thermal characteristics. The simulation shows that increasing the convective heat transfer coefficient is beneficial to lower the battery’s temperature.