High-rate yet dendrite-free lithium-metal batteries enabled by epitaxial growth of lithiophilic Cu particles on Cu foils with a double reducing agent strategy

Abstract

High-rate capability of lithium-metal batteries (LMBs) provides great advantages for developing the next-generation of electronic devices. However, increasing the charge/discharge rates will easily trigger serious lithium-dendrite issue and dangerous heat accumulation, severely hindering the safe utilization of LMBs. Here we develop a novel epitaxial growth strategy to anchor lithiophilic/monodisperse Cu particles on Cu foils (EG-Cu@Cu) to improve the deposition quality of lithium for dendrite-free LMBs. Highly exposed active sites based on the EG-Cu@Cu structure endow the electrodes with high ionic/electronic conductivity, and thus significantly promote the charge/discharge rates of LMBs. The resulting lithium-metal anodes based on the EG-Cu@Cu structure demonstrate a dramatical improvement in voltage hysteresis as the current density increases from 0.25 to 3 mA cm⁻², indicating outstanding rate capability for fast-charge applications. When coupled with LiFePO₄ cathodes, LMBs based on the EG-Cu@Cu structure exhibit excellent rate performance and superior cycling stability (e.g., stable running for 280 cycles at 1C). This study offers a new perspective for achieving high-rate LMBs with simultaneously considering their operation safety under harsh test conditions.