A 3D lithiophilic ZIF-8@RGO free-standing scaffold with dendrite-free behavior enabling high-performance Li metal batteries

Abstract

Li metal is an attractive anode material for electrochemical energy storage. However, the growth of Li dendrites accompanied with infinity-dimension changes, which leads to decreased coulombic efficiency and Li utilization, has long hampered practical application in rechargeable Li-metal batteries. Herein, a 3D ZIF-8@RGO scaffold with in-situ-formed abundant N/Zn sites after a convenient carbonization strategy is successfully demonstrated as both current collector and host material for Li metal anodes. Preferential Li deposition is predominantly accommodated into the 3D matrix free of dendrites by the synergetic effect of lithiophilic N/Zn nucleation sites and free-standing RGO with outstanding conductive properties. Profiting from the selective deposition and stable encapsulation, Li/ZIF-8@RGO anodes with preloading 5 mA h cm⁻² Li can run for 600 h without short circuit and deliver a promoted coulombic efficiency of ∼98.48% over 350 cycles. Moreover, the ZIF-8@RGO-based full cells exhibit exceptional cycling stability and rate capability.