A lithiophilic hyperbranched polymer-decorated three-dimensional carbon skeleton boosting highly reversible lithium metal anode

Abstract

The short cycling lifespan and serious safety issues caused by the crazy growth of dendrites, have severely restricted the practical application of Li metal anodes (LMAs) in high energy density batteries. Here, a three-dimensional (3D) porous conductive framework enriched with lithiophilic functional groups is proposed for stabilizing Li metal anodes, which is fabricated by coating hyperbranched polyol (HP) on the carbon fiber cloth (CFC) through a simple esterification reaction. The abundant lithiophilic groups distributed on HP can disperse the Li ion flow and guide the uniform nucleation of Li. The 3D porous skeleton not only promotes ion diffusion and electron transport but also provides adequate space for Li storage. Symmetrical battery configurated with CFC@HP-Li hybrid anode demonstrates stable cycling over 800 h with low voltage hysteresis at a current density of 2 mA cm−2. With a commercial LiFePO4 (LFP) cathode, the CFC@HP-Li//LFP full battery can realize a high capacity retention rate of 88.9% and a stable Coulombic efficiency (CE) close to 100% after 500 cycles at 2 C. The CFC@HP-Li anode, which is constructed by a modification of LMAs using the targeted lithiophilic coating, provides a promising strategy for the exploration of high-performance Li metal batteries (LMBs).