Hybrid Controller Automatic Fast Charging with Capacity Retention for Lithium Ion Batteries

The widespread adoption of lithium-ion battery-based electrification applications is being hindered by inherently slow recharge rate and capacity fade. Fast charge techniques using traditional constant current constant voltage (CCCV) with amplified current can reduce charge times but results in significantly lowered cycle life and endurance. Novel fast charge techniques utilizing positive, negative, and alternating pulses have demonstrated improvement in charge times while decelerating battery degradation compared to high rate CCCV methods. However, details of practical and efficient implementation of these methods are lacking. The hybrid controller presented in this work is a proposed solution and enabling technology capable of applying amplified pulses of energy to and from the battery during charging. The hybrid controller dynamically moves energy between the lithium-ion battery and an integrated supercapacitor supporting the pulsed nature of the charge profile with minimal dissipative losses. The architecture allows for an efficient method of applying the alternating pulsed power charging algorithms. Experimental data from initial testing is presented for a hybrid enabled efficient fast charging algorithm utilizing bidirectional energy pulses. The preliminary data shows 40% improvement in charging time over standard CCCV methods while also greatly reducing power fade and capacity fade to a level that is only 2% below standard CCCV. These are critical improvements for power and endurance applications.