Non‐Flammable Li‐Diamond Composite Anode Enabling High‐Safety Lithium Metal Batteries

The high reactivity of lithium metal anodes has persistently hindered their practical implementation. Herein, aiming to enhance both the safety and electrochemical performance of lithium metal anodes, we fabricated an ultrathin composite anode via mechanical rolling of zinc oxide (ZnO) modified diamond particles with lithium foil. The diamond component imparts exceptional safety to the composite anode. Under thermal abuse conditions, inert products formed at the Li‐diamond interface rapidly isolate metallic lithium from atmospheric oxygen, effectively suppressing lithium droplet formation and enabling prompt self‐extinguishment upon flame exposure. When paired with a non‐flammable electrolyte, the assembled pouch cell demonstrates outstanding safety under heating. Furthermore, using the same preparation method, we demonstrate that other carbon materials also enhance the inherent safety of lithium metal. This work provides a new perspective on lithium‐carbon composite anodes and facilitates the development of intrinsically safe lithium metal anodes.