Insight into pulse-charging for lithium plating-free fast-charging lithium-ion batteries

Abstract

• Mechanism of pulse-current-based fast-charging to suppress Li plating. • Pulse-current mitigates Li plating and capacity fading during fast-charging. • Physics-based modeling predicts Li + redistribution during pulse-current cycling. • Relaxation of the Li + concentration mitigates the anode potential drop. In recent years, tremendous efforts have been devoted to searching for the fast-charging methodology of lithium-ion battery (LIB) with widespread practical application of the electric vehicles, since the uncontrolled Li plating on the graphite anode under the fast-charging condition can lead the accelerated capacity decay and cause the safety issues of LIB. Here, we present mechanistic insights into the pulse-current-based fast-charging to aid with suppressing Li plating on the graphite anode. Compared with a conventional fast-charging protocol of the constant current method, the full-cell assembled with graphite anode and LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode exhibits the improved fast-charging capability and cycle performance under the pulse-charging protocol. In particular, the graphite anode after prolonged 300 cycles shows a clean surface free of plated Li, which confirms that the pulse-charging protocol effectively inhibits Li plating on the anode even under fast-charging conditions. Furthermore, the physics-based numerical modeling results demonstrate that the pulse-current redistributes the accumulated Li + species at the electrolyte/anode interface periodically, which mitigates the anode potential drop and prevents consequent Li plating.