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

초록

In recent years, tremendous efforts have been devoted to searching for the fast-charging methodology of lithiumion 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 LiNi0.6Co0.2Mn0.2O2 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.

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