An Advanced Battery Charging System Using Bipolar Pulse Strategy for Lithium-Ion Battery Durability Enhancement

With the increasing deployment of energy storage devices in electric vehicles and distributed renewable power network, the extensive research on battery charging systems has shown a growing significance. This paper focuses on developing a new charging method which aims at extending the lifespan of lithium-ion battery by using bipolar current pulses. A battery charging system employing a phase-shift controlled dual active bridge and battery elements has been studied and its small-signal average model is established to investigate the dynamic control of the proposed bipolar pulse charging approach. Furthermore, the influence of the negative pulse on eliminating the polarization effect and inhibiting the ageing of the lithium-ion battery has been analyzed in detail. Finally, an advanced four-stage battery charging strategy is proposed for the ageing effect suppression and battery lifetime extension, without compromising the charging speed. An average of 7.58% charging time reduction is resulted compared with the traditional charging method.