Bottom-up deposition of lithium on 3D lithiophobic–lithiophilic host for long-life lithium metal anodes

Abstract

Rational structure design of 3D hosts is one of the most promising strategies to achieve uniform Li deposition and inhibit the uncontrolled growth of Li dendrites. Herein, a 3D-C_TPA skeleton with lithiophobic–lithiophilic properties was used for the fabrication of a 3D composite Li anode (3D-C_TPA@Li) by electrodeposition. The resulting 3D-C_TPA@Li symmetric cell showed a long lifespan of 2000 h at 1 mA cm⁻² for 1 mA h cm⁻². Additionally, the 3D-C_TPA@Li/LiFePO₄ full cell exhibited long cyclic stability with 86.6% capacity retention after 500 cycles at 0.5C. The good electrochemical performance of the 3D-C_TPA@Li anode can be attributed to the unique features of the 3D-C_TPA skeleton, which resulted in dominant Li(110) facets for enhanced electrochemical kinetics. This was supported by XPS results, which indicated the formation of an inorganic-rich SEI layer on the surface of the 3D-C_TPA@Li anode. The robust SEI layer with heterogenous electronic insulated/ionic conductive (Li₃N/LiF) properties could effectively inhibit the reduction of Li⁺ and the electrolyte on the surface of the 3D-C_TPA@Li anode, as well as serve as an “ionic sieve” to realize uniform and fast Li⁺ transport through the interface. Consequently, metallic Li preferentially nucleated/grew inside the 3D-C_TPA pore spaces with bottom-up Li deposition.