Constructing a 3D Li[sbnd]Mg alloy skeleton through mechanical rolling for high-rate Li anodes

Abstract

Li is a promising anode material for lithium-ion batteries owing to its low redox potential (−3.04 V vs. standard hydrogen electrode) and exceptionally high theoretical specific capacity (3860 mAh g−1). However, considerable volume changes and uncontrolled dendrite growth reduce coulombic efficiency during charge/discharge cycles, limiting its practical application. This research introduces a straightforward method to fabricate a two-phase intertwined composite electrode featuring a LiMg phase as a three-dimensional (3D) skeleton structure aimed at high-rate Li-metal batteries. With its mixed electronic and ionic conducting networks, the 3D alloy structure offers abundant interfaces with pure Li and exhibits strong lithium affinity, enhancing Li+ diffusion throughout the electrode and enabling dendrite-free deposition. Results demonstrate a long cycle life exceeding 80 h at 30 mA cm−2 in symmetric cells. Coin- and pouch-type full cells with cathodes also show excellent rate capacity and cycling stability. The exceptional performance of this material makes it a highly desirable anode for high-rate lithium-metal batteries.