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.

中文翻译：

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快充锂离子电池镀锂原理及改进


快速充电主要受到锂 (Li) 电镀风险的限制，这种副反应可能导致锂离子电池 (LIB) 的容量快速衰减和枝晶引起的热失控。研究锂镀层的内在机制和位置对于提高锂离子电池的快速充电性能和安全性至关重要。在此，我们研究了Li限制传输下多孔电极中的Li电镀行为。基于理论模型，可以得出结论，阳极-隔膜界面（ASI）上的锂镀层在热力学上是可行的并且在动力学上是有利的。同时，实验验证了金属Li预先沉积在ASI而不是阳极集流体界面（ACI）上。为了促进锂在电极之间的转移并提高活性材料的利用率，而无需镀锂，提出了一种由石墨和硬碳（GH）组成的双层不对称负极。实验和模拟结果表明，GH 混合电极使整个电极的锂化率均匀化，并且在倍率性能和锂沉积抑制方面优于纯石墨电极。这项工作为锂电镀行为和电极结构的合理设计提供了新的见解。