Robust, Ultrasmooth Fluorinated Lithium Metal Interphase Feasible via Lithiophilic Graphene Quantum Dots for Dendrite‐Less Batteries
Chenrayan Senthil, Seung Gyu Kim, Sun‐Sik Kim, Myung Gwan Hahm, Hyun Young Jung
Abstract
Abstract Dendrite growth and in‐homogeneous solid electrolyte interphase (SEI) buildup of Li metal anodes hinder the longtime discharge–charge cycling and safety in secondary metal batteries. Here, the authors report an in‐situ restructured artificial lithium/electrolyte SEI exposing an ultrasmooth and thin layer mediated through graphene quantum dots (GQDs). The reformed artificial interphase comprises a mixture of organic/inorganic‐rich compositions alike as mosaic interphase, albeit the synergistic effect mediated via hydroxylated GQDs involving redeposition‐borne lithium, and its accumulated salts, facilitate a homogeneous and ultrasmooth near fluorine‐rich interfacial environment ensuring a facile lithium‐ion (Li‐ion) diffusion and dendritic‐free nature. As a result, symmetrical graphene dots‐lithium cells enable a dendrite‐less operation up to 2000 h with good cycling stability and capacity retention at current densities 1 and 5 mA cm −2 compared to bare lithium. The well‐established fluorinated interface engenders a high reversible capacity and stable performance during the initial and long‐term cycles upon configuring in lithium‐sulfur (Li‐S) cells. Thus, the authors’ work illuminates the direction toward achieving dendritic‐free smooth and robust metal anodes through manipulating and restructuring the critical SEI chemical components.