3D Vertically Aligned Li Metal Anodes with Ultrahigh Cycling Currents and Capacities of 10 mA cm-2/20 mAh cm-2 Realized by Selective Nucleation within Microchannel Walls

Although metallic lithium is regarded as the Holy Grail for next-generation rechargeable batteries due to its high theoretical capacity and low overpotential, the uncontrollable Li dendrite growth, especially under high current densities and deep plating/striping, has inhibited its practical application. Herein, a 3D-printed, vertically aligned Li anode (3DP-VALi) is shown to efficiently guide Li deposition via a nucleation within microchannel walls process, enabling a high-performance, dendrite-free Li anode. Moreover, the microchannels within the microwalls are beneficial for promoting fast Li+ diffusion, supplying large space for the accommodation of Li during the plating/stripping process. The high-surface-area 3D anode design enables high operating current densities and high areal capacities. As a result, the Li-Li symmetric cells using 3DP-VALi demonstrate excellent electrochemical performances as high as 10 mA cm(-2)/10 mAh cm(-2) for 1500 h and 5 mA cm(-2)/20 mAh cm(-2) for 400 h, respectively. Additionally, the Li-S and Li-LiFePO4 cells using 3DP-VALi anodes present excellent cycling stability up to 250 and 800 cycles at a rate of 1 C, respectively. It is believed that these new findings could open a new window for dendrite-free metal anode design and pave the way toward energy storage devices with high energy/power density.