Atomic Layer Deposition of Zinc-Oxide Layers for Photoassisted Lithium Metal Batteries

The lithium metal anode offers a high theoretical capacity (3860 mAh g^-1) and a low electrochemical potential (-3.040 V vs SHE). These properties make it a promising candidate for use as an anode in next-generation lithium-ion batteries. However, the uneven deposition and stripping of lithium lead to dendrite growth and instability of the solid electrolyte interface. These problems seriously hinder the practical application of lithium metal batteries. Stable Li anodes enabled by a uniform lithiophilic nucleation layer and photoassisted current collectors are highly desirable. However, only a few studies have explored this approach. In this work, a thin ZnO layer was conformally deposited onto a 3D current collector via atomic layer deposition (ALD) to achieve uniform and stable lithium metal growth. The ZnO layer serves as a lithium nucleation layer and provides photoresponsiveness, thereby facilitating subsequent photoassisted deposition. This modification induced local carrier redistribution, reduced the overpotential by 25.5 mV, and significantly enhanced the lithium deposition kinetics. A high Coulombic efficiency of 96.56% was achieved at 3 mA cm^-2 after 300 cycles. These findings provide valuable insights into the development of next-generation photoassisted Li metal anodes, highlighting their potential for improved performance and stability.