In-situ polymerization strategy to construct stable electrode/electrolyte interfaces for high-performance lithium metal batteries

The unstable electrode/electrolyte interface formed in conventional electrolytes is a major factor limiting the large-scale application of lithium metal batteries (LMBs). Herein, we propose a strategy for in-situ polymerization of additives, using N,O-bis(trimethylsilyl)acetamide (BSA) and vinyl carbonate (VC) as synergistic additives to construct a stable and robust solid electrolyte interface (SEI) through in-situ polymerization reaction, significantly reducing interface impedance. In addition, BSA can effectively scavenge HF and inhibit electrolyte decomposition. The Li||Li symmetric cell with VC and BSA additives exhibits stable cycling for over 600 h at 1 mA cm⁻² with a capacity of 1mAh cm⁻², and LiFePO₄ (LFP)||Li full cell shows a rate capability of exceeding 118 mAh g⁻¹ and excellent cycle stability of 2000 cycles at 10C. This work provides a facile and effective strategy for LMBs to construct stable interfaces.