Macroscopic Architecture Design of Lithium Metal Electrodes: Impacts of Millimeter-Size Hollows on Economization, Cyclability, and Utilization

A macroscopic architecture design of lithium metal electrodes for solving the problem of extremely excessive lithium metal is proposed in this paper. By employing a simple mechanical processing method, macroscopic hollows within lithium foils are introduced, and consequently, the amount of lithium metal has economized significantly. The cyclability of lithium foils with millimeter-size hollows is evaluated jointly via modeling and experiments. The results suggest that the well-designed macroscopic hollow causes controllable sacrifices of battery cycling performances and considerably boosts the utilization of lithium metal. The relationship of economization, cyclability, and utilization of lithium metal is also discussed. The universality of the results is also verified in different battery systems. Meanwhile, the initial hollows are found to heal morphologically after a series of electrochemical cycles, and the existence of lithium metal in the healing product is also confirmed, indicating that hollows provide room for the in-plane lithium dendrite growth. Based on these findings, this work provides a new perspective on the architectural design of lithium metal electrodes.