Interlamellar Lithium‐Ion Conductor Reformed Interface for High Performance Lithium Metal Anode

Abstract

AbstractLithium metal anodes are promising for application in new‐type secondary batteries. Unfortunately, low cycle life and safety peril induced by uncontrollable dendrites growth and weak solid electrolyte interface (SEI) have blocked their utilization. In this work, an interlamellar lithium‐ion conductor of lithium‐montmorillonite (Li‐MMT) is applied to enhance the SEI properties, inhibit dendrites‐germination, and thus significantly enhance electrochemical performance. Such a well‐designed Li‐MMT SEI not only possesses inherent fast lithium‐ion channels, but also works as a reservoir to supply adequate lithium‐ions in the interlaminations and periphery of Li‐MMT nanosheets, offering fast lithium‐ion transfer in interlaminations and sheet‐to‐sheet. Furthermore, the strong trend of lithium‐ion absorption of Li‐MMT is confirmed by density functional theory calculations and stable lithium deposition under Li‐MMT SEI layer at 10 mA cm−2is verified via finite element modeling. As a result, a steady lithium deposition process without dendrites is achieved. Coulombic efficiency of the half‐cell accomplishes a mean value of 99.1% over 400 cycles at 1 mA cm−2, while Li‐LiFePO4full cells show a stable capacity up to 120 mAh g−1and steady circulation over 400 loops at 1C. This work offers a novel strategy to design a high‐performance SEI layer and suppress dendrite growth.