Self-smoothing lithium metal anode based on screen-printed Cu-mesh current collector for long-term safety of lithium metal batteries

Lithium metal is an attractive anode candidate to enable high-energy lithium battery systems. However, nonideal dendrite growth at the anode/separator interface hinders the safe application of lithium metal batteries (LMBs). Three-dimensional (3D) current collectors (CCs) with high specific surface area could afford a crucial effect on suppressing dendrites, yet still subject to large thickness/weight and limited scalability for large-area fabrication. Here, we show an industry-compatible screen-printing technique to prepare ultrathin (∼1.5 μm) and ultralight (∼0.54 mg cm⁻²) Cu mesh on commercial Cu foil to realize a long-term safety of LMBs. In contrast to conventional laboratory level techniques, the screen-printed Cu-mesh CCs (∼8.3 mg cm⁻²), which are even lighter than the original Cu foil (∼8.84 mg cm⁻²), show a high compatibility for large-area fabrication. Meanwhile, the periodic Cu mesh can be also used to regulate the homogeneous distribution of Li-ion flux and thus, be in favor of realizing self-smoothing anodes at even deep and fast plating/stripping of lithium. The resulting lithium anodes demonstrate a long-term cyclic life of ∼840 h at 1 mA cm⁻² with a high Coulombic efficiency of 97.5%. LMBs with Cu-mesh CCs exhibit outstanding capacity retentions of ∼87% after 350 cycles at 1 C and ∼80% after 200 cycles at 5 C, suggesting a significant step of printable 3D CCs toward practical application of high-energy LMBs.