In Situ Generated Mixed Ion/Electron-Conducting Scaffold with Uniform Li Deposition for Flexible Li Metal Anodes

Carbon cloth (CC) is widely used as a three-dimensional (3D) substrate for flexible energy-storage devices, but its application in flexible Li metal anode is still limited. One of the most critical problems is the uneven Li deposition on top of the CC due to the lithiophobic and electron-conducting nature, which induces the uncontrollable Li dendrite growth leading to short circuit and other safety issues. Here, we report a mixed ion/electron-conducting scaffold (MIECS) as a flexible Li metal anode host, synthesized through the in situ conversion of Cu2S into the high Li-ion-conductive Li2S layer on the CC skeleton. Together with high lithiophilicity, the MIECS can achieve homogeneous Li-ion flux, which realizes uniform Li nucleation and growth in the whole structure via balanced ion/electron transport. Thus, the MIECS displays enhanced electrochemical performances with ultrahigh coulombic efficiency, long cyclic life, good rate performance, and high flexibility. Furthermore, the full battery coupled with organic cathode shows excellent flexibility and superior cyclic stability even after bending 1000 cycles. This work provides insight into the promising potential of 3D MIECS for flexible Li metal anodes.