Ultralight Ag-grid current collector enabled by screen printing Ag ink on Cu foil as efficient deposition-inducing layer for dendrite-free lithium metal batteries

Abstract

Metallic lithium exhibits considerable advantages that make it applicable in future high-energy battery systems. However, the infinite growth of dendritic lithium at the anode/separator interface poses serious safety threats (e.g., battery fire and explosion) to the practical application of lithium metal anodes. In contrast to laboratory-level technologies for dendrite suppression, we show an efficient deposition-inducing strategy that entails screen printing grid-like Ag pattern on commercial Cu foil to foster a smooth lithium-deposition behavior. The scalable screen-printing technique enables large-scale fabrication of the Cu@Ag grids, while the ultrathin (∼2 μm) and ultralight (∼1.4 mg cm⁻²) Ag grids render a low thickness and weight of 3D current collectors, and thus supports the precondition for realizing high-energy lithium batteries. Dendrite-free lithium metal anodes with ultrasmooth anode surfaces are achieved via the precise regulation of the lithium deposition process. The resulting lithium anodes exhibit a high Coulombic efficiency of ∼97.2% and a long-term cyclic stability of 700 h at 1 mA cm⁻². Lithium metal batteries with Cu@Ag grids show stable cycling for ∼300 cycles at 1C and ∼150 cycles at 5C, suggesting the potential for the 3D-grid structure to be used in next generation high-energy lithium metal batteries.