Engineering the Current Collector Interface by Atomic Layer Deposition for Fast Charging of Lithium Metal Batteries

Enabling fast charging conditions in high energy density batteries is crucial for supporting the electrification of the transportation sector. Here, we introduce a strategy to support fast charging in lithium metal batteries by using atomic layer deposition to coat the copper current collector with a resistive Al2O3 thin film. The film constrains electron transfer to low-resistance defect sites, leading to the regulation of Li+ ion transfer and concentration profiles. Results show that limiting nucleation sites promotes the lateral growth of beneficial low-surface-area lithium deposits at current densities of up to 20 mA cm–2, an effect attributed to the radial diffusion of Li+ ions. We also show that the Al2O3 thin film incorporates a greater degree of beneficial inorganic species and LiF into the solid electrolyte interface at high current densities. For charging rates of 5 mA cm–2, the cumulative benefits allow cells with the resistive Al2O3 coating to achieve Coulombic efficiencies nearly 8% greater than bare copper over the first 100 cycles and support an additional 100 cycles at Coulombic efficiencies above 80% in carbonate electrolytes.