Lifetime Extension of Lithium-ion Batteries with Low-Frequency Pulsed Current Charging

The pulsed current has been proposed to achieve fast charging and extend the lifetime of lithium-ion (Li-ion) batteries. However, the optimal condition of the pulsed current is still inconclusive in previous studies. This article experimentally investigated the effect of the low-frequency positive pulsed current (PPC) charging on the lifetime and charging performance of Li-ion batteries. A two-stage degradation model of Li-ion batteries is developed to determine the inhibitory effect of the PPC on degradation mechanisms at different aging stages. Moreover, the changes in the internal resistance (IR) and the incremental capacity (IC) curve are provided to thoroughly explore the effects of the PPC on the degradation of Li-ion batteries. Compared with the traditional constant current (CC) charging, the lifetime, maximum rising temperature, and energy efficiency of the Li-ion batteries that were cycled by the PPC charging are improved by 81.6%, 60.5%, and 9.1%, respectively, after 1000 cycles. Therefore, low-frequency PPC charging should be considered as a promising charging strategy for Li-ion batteries.