Advanced Hierarchical Lithiophilic Scaffold Design to Facilitate Synchronous Deposition for Dendrite-Free Lithium Metal Batteries

Abstract

Localized deposition behavior tends to induce the growth of lithium dendrite and hinder the the full utilization of lithium storage space, significantly impeding the practical application of 3D conductive hosts. Here, a novel synchronous deposition mode is proposed for the first time through hierarchical structure design of 3D Li host. The top-down gradually enhanced lithiophilicity and conductivity of 3D scaffold provide sufficient driving force for Li⁺ to migrate downward, promoting synchronous Li deposition within the entire space of the host. Notably, the novel deposition mode has been theoretically and experimentally validated through finite element simulation and in situ optical microscopy, respectively. The meticulously designed strategy not only maximizes the utilization of the entire 3D scaffold space but also prevents the formation of Li dendrites under high current rate. Consequently, the symmetric Li//Li cell exhibits a long-term cycling lifespan over 3700 h with a low overpotential of 15.6 mV, together with a Coulombic efficiency as high as 99.5% over 300 cycles at 3 mA cm⁻². The full cell paired with LiFePO₄ cathode demonstrates a cycling lifespan of 1000 cycles with a capacity retention rate of 91.6%. The proposed synchronous deposition strategy opens up a new paradigm for the design and construction of 3D hosts for dendrite-free Li metal anode.