Topological Li-SbF3@Cu Alloying Anode for High-Energy-Density Li Metal Batteries

Abstract

The ultrathin Lithium (Li) alloying anode (≤ 50 µm) plays a key role in advancing rechargeable Li metal batteries into practical use, especially because of the insurmountable difficulties in developing pure Li anode. Herein, a thickness-controllable (≈5.5–30 µm) and topological Li-SbF₃@Cu anode with the embedded dual Li-based (Li₃Sb and Li-Cu) alloys and outmost LiF-rich layer is prepared for high-energy-density Li metal batteries under high Li utilization. Upon cycling, the surface LiF-rich layer together with inner lithiophilic Li₃Sb sites and ferroconcrete-like Li-Cu skeletons, synergistically regulates the Li deposition/dissolution behaviors and Li/electrolyte interface evolution. The assembled Li-SbF₃@Cu symmetric cell can cycle stably over 1200 h at 1 mA cm⁻²/1 mAh cm⁻², and realize an ultrahigh discharge/charge depth of 53.6% at 2 mA cm⁻²/3 mAh cm⁻². Moreover, a full cell with a high-Li-capacity LiCoO₂ cathode (3.8 mAh cm⁻²) delivers an energy density of 394.5 Wh kg⁻¹ with impressive cycling reversibility at a low negative/positive electrode capacity (N/P) ratio of 1.5. All the findings provide a rewarding avenue toward the industrial application of high-Li-utilization alloying anodes for practical high-energy-density Li metal batteries.