The practical implementation of Li metal batteries is hindered by difficulties in controlling the Li metal plating microstructure. While previous atomic layer deposition (ALD) studies have focused on directly coating Li metal with thin films for the passivation of the electrode–electrolyte interface, a different approach is adopted, situating the ALD film beneath Li metal and directly on the copper current collector. A mechanistic explanation for this simple strategy of controlling the Li metal plating microstructure using TiO₂ grown on copper foil by ALD is presented. In contrast to previous studies where ALD‐grown layers act as artificial interphases, this TiO₂ layer resides at the copper–Li metal interface, acting as a nucleation layer to improve the Li metal plating morphology. Upon lithiation of TiO₂, a Li_xTiO₂ complex forms; this alloy provides a lithiophilic surface layer that enables uniform and reversible Li plating. The reversibility of lithium deposition is evident from the champion cell (5 nm TiO₂), which displays an average Coulombic efficiency (CE) of 96% after 150 cycles at a moderate current density of 1 mA cm⁻². This simple approach provides the first account of the mechanism of ALD‐derived Li nucleation control and suggests new possibilities for future ALD‐synthesized nucleation layers.

中文翻译：

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揭示和阐明ALD对锂电镀微结构的控制

锂金属电池的实际实施受到难以控制锂金属镀层微观结构的阻碍。虽然先前的原子层沉积（ALD）研究集中在直接用薄膜涂覆锂金属以钝化电极-电解质界面，但采用了另一种方法，将ALD膜置于锂金属下方并直接在铜集流体上。提出了这种简单的策略的机械解释，该策略使用通过ALD在铜箔上生长的TiO ₂来控制Li金属镀层的微观结构。与以前的研究相比，以前的研究将ALD层作为人工中间相，这种TiO ₂层位于铜-锂金属的界面处，充当成核层以改善锂金属的镀层形态。在TiO ₂锂化时，形成Li _x TiO ₂络合物。这种合金提供了一个亲锂表面层，能够实现均匀且可逆的锂镀层。从冠军电池（5 nm TiO ₂）可以明显看出锂沉积的可逆性，该冠军电池在1 mA cm ^-2的中等电流密度下经过150次循环后，平均库仑效率（CE）为96％。这种简单的方法首次说明了ALD衍生的Li成核控制机制，并为将来的ALD合成的成核层提供了新的可能性。