Firstly, using the C–R pulse mode, it was determined that pulse charging has a positive impact on shortening the charging time for both LFP batteries and NMC batteries, and a smaller frequency is the key to improving battery performance and shortening the total charging time. For the C–R mode, the pulse current amplitude has the greatest impact.
Pulse charging of a lithium-ion battery has several advantages. It can prevent lithium dendrites from growing, form stable solid electrolyte (SEI) films [27, 28], and preheat lithium batteries at low temperatures [29, 30]. Hence pulse charging can prolong the life of lithium-ion batteries [31, 32].
Specifically, the average internal resistance in the C-D mode is nearly 17.5 % lower than that of the CC-CV mode, demonstrating that the pulse charging has superior performance in enhancing battery cycle life and efficiency. 4.5. Battery cycle life testing results
The model results show that pulse charging enhances uniformity of lithium-ion distribution in the battery, thereby improving the battery performance. This research demonstrates pulse charging is a viable option to improve battery charging performance at low temperatures compared to the CC-CV charging method. 1. Introduction
Results published in existing literature are not in complete agreement regarding the effects of pulse charging. Several studies claim to have beneficial effects on charging efficiency, charging time, and capacity fade. While others have found disadvantageous effects on the same parameters.
The advantage of this method is that it can generate a large amount of heat in a short period, lowering the impedance, and thus reducing the capacity loss of battery [24, 25]. Pulse charging refers to the use of periodically changing current to charge the battery. The pulse current can be positive (i.e. charging) or negative (i.e. discharging).