Copper Nitride Nanowires Printed Li with Stable Cycling for Li Metal Batteries in Carbonate Electrolytes

Abstract The practical implementation of the lithium metal anode is hindered by obstacles such as Li dendrite growth, large volume changes, and poor lifespan. Here, copper nitride nanowires (Cu 3 N NWs) printed Li by a facile and low‐cost roll‐press method is reported, to operate in carbonate electrolytes for high‐voltage cathode materials. Through one‐step roll pressing, Cu 3 N NWs can be conformally printed onto the Li metal surface, and form a Li 3 N@Cu NWs layer on the Li metal. The Li 3 N@Cu NWs layer can assist homogeneous Li‐ion flux with the 3D channel structure, as well as the high Li‐ion conductivity of the Li 3 N. With those beneficial effects, the Li 3 N@Cu NWs layer can guide Li to deposit into a dense and planar structure without Li‐dendrite growth. Li metal with Li 3 N@Cu NWs protection layer exhibits outstanding cycling performances even at a high current density of 5.0 mA cm −2 with low overpotentials in Li symmetric cells. Furthermore, the stable cyclability and improved rate capability can be realized in a full cell using LiCoO 2 over 300 cycles. When decoupling the irreversible reactions of the cathode using Li 4 T i5 O 12 , stable cycling performance over 1000 cycles can be achieved at a practical current density of ≈2 mA cm −2 .