Shape‐Controlled Reversible Li Plating‐Stripping for Stable and High‐Rate Anode‐Free Lithium Metal Batteries

Abstract

AbstractAnode‐free lithium metal batteries are promising toward high‐energy‐density power sources with low‐cost, but their practical applications are challenged by poor cycling stability and low rate capability. Herein, a shape change‐free and lithium‐free anode that well controls the reversible Li plating‐stripping is reported, which is composed of a highly‐ordered hollow ZnO matrix with a surface‐coated lithium‐phosphorus‐oxynitride (LiPON) layer. The ZnO matrix supplies sufficient cavities and lithiophilic sites to facilitate uniform Li plating/stripping within the hollow cavity, while the LiPON layer maintains stable solid‐electrolyte interphase from mechanical and electrochemical damage. As a result, lithium is constrained within the cavity and the overall anode shape is effectively controlled during long‐term and high‐rate cycling. The assembled half‐cell stably works at 1.2 mA cm−2 for 335 cycles with Coulombic efficiency of 98.8%. Without Li pre‐deposition, full‐cells using modified‐LiFePO4 and LiNi0.5Co0.2Mn0.3O2 cathodes demonstrate 150‐cycles lifespan and high energy density of 617 Wh kg−1 at 2C rate.