Implementation of Variable Duty Ratio Reflex Charging of Li-ion Batteries

Abstract

In today scenario, a proper battery charging method is vital. There are many methods to charge the lithium battery like constant current(CC), constant current constant voltage(CC-CV), Multistage constant current(MS-CC), pulse charging, and Reflex charging. In the Reflex method, a high pulse current is used to decrease the time consumption for charging, and the negative pulse of the reflex method along with rest period reverses the chemical action, thereby decreases the internal pressure as well as the amount of Li-ion saturation at graphite. Different types of reflex method are there,like constant pulse width and variable frequency. A duty cycle varied Reflex charging method is proposed in this paper to charge the Li-ion batteries using a bidirectional converter. The duty ratio of this reflex method will vary according to the charge stored in the battery. The main advantage of the proposed method is, efficient and fast charging of Li-ion batteries. Using this method, the Lithium quantity decreases during the formation of a solid electrolyte interface(SEI). Hence, the life cycles of batteries is increased. This scheme involves, varying the duty cycle of the charging current such that the charge rate is greater than the conventional reflex charge rate. This strategy is simulated and analyzed and also compared with the conventional constant pulse width reflex charging method and the CC-CV method.