Understanding the electrochemical deposition of metal anodes is critical for high-energy rechargeable batteries, among which solid-state lithium metal batteries have attracted extensive interest. A long-standing open question is how electrochemically deposited lithium-ions at the interfaces with the solid-electrolytes crystalize into lithium metal. Here, using large-scale molecular dynamics simulations, we study and reveal the atomistic pathways and energy barriers of lithium crystallization at the solid interfaces. In contrast to the conventional understanding, lithium crystallization takes multi-step pathways mediated by interfacial lithium atoms with disordered and random-closed-packed configurations as intermediate steps, which give rise to the energy barrier of crystallization. This understanding of multi-step crystallization pathways extends the applicability of Ostwald’s step rule to interfacial atom states, and enables a rational strategy for lower-barrier crystallization by promoting favorable interfacial atom states as intermediate steps through interfacial engineering. Our findings open rationally guided avenues of interfacial engineering for facilitating the crystallization in metal electrodes for solid-state batteries and can be generally applicable for fast crystal growth.

了解金属阳极的电化学沉积对于高能可充电电池至关重要，其中固态锂金属电池引起了广泛的兴趣。一个长期悬而未决的问题是，在与固体电解质的界面处电化学沉积的锂离子如何结晶成锂金属。在这里，我们使用大规模分子动力学模拟，研究并揭示了固体界面处锂结晶的原子路径和能垒。与传统理解相反，锂结晶采用多步途径，由界面锂原子介导，具有无序和随机闭堆积构型作为中间步骤，从而产生结晶能垒。这种对多步结晶路径的理解将奥斯特瓦尔德步进规则的适用性扩展到界面原子态，并通过界面工程将有利的界面原子态作为中间步骤来促进低势垒结晶的合理策略。我们的研究结果开辟了界面工程的合理指导途径，以促进固态电池金属电极的结晶，并且普遍适用于快速晶体生长。