The principle and amelioration of lithium plating in fast-charging lithium-ion batteries

Abstract

Fast charging is restricted primarily by the risk of lithium (Li) plating, a side reaction that can lead to the rapid capacity decay and dendrite-induced thermal runaway of lithium-ion batteries (LIBs). Investigation on the intrinsic mechanism and the position of Li plating is crucial to improving the fast rechargeability and safety of LIBs. Herein, we investigate the Li plating behavior in porous electrodes under the restricted transport of Li+. Based on the theoretical model, it can be concluded that the Li plating on the anode-separator interface (ASI) is thermodynamically feasible and kinetically advantageous. Meanwhile, the prior deposition of metal Li on the ASI rather than the anode-current collector interface (ACI) is verified experimentally. In order to facilitate the transfer of Li+ among the electrode and improve the utilization of active materials without Li plating, a bilayer asymmetric anode composed of graphite and hard carbon (GH) is proposed. Experimental and simulation results suggest that the GH hybrid electrode homogenizes the lithiated-rate throughout the electrode and outperforms the pure graphite electrode in terms of the rate performance and inhibition of Li plating. This work provides new insights into the behavior of Li plating and the rational design of electrode structure.