LiNO3‐Based Electrolyte with Fast Kinetics for Lithium Metal Batteries Under Practical Conditions

A LiNO₃-based electrolyte enables lithium metal batteries to achieve exceptional cycling stability (430 cycles) and ultrafast kinetics (2.35 mAh cm⁻² at 12 mA cm⁻²) under practical conditions. The electrolyte's unique solvation structure and Li₂O-Li₃N-rich interphase facilitate rapid ion transport, outperforming costly LiFSI-based systems and paving the way for commercially viable high-energy batteries.

Abstract

To be commercially viable, the electrolyte for lithium metal batteries (LMBs) must enable both long cycle life and fast charging characteristics under extreme conditions (high cathode loading, low negative/positive ratio, and low electrolyte/cathode ratio). While LiFSI-based electrolytes typically provide LMBs with extended cycle life, they often fall short in terms of kinetics. This study, for the first time, demonstrates that the LiNO₃-based electrolyte can simultaneously achieve excellent reversibility and rapid kinetics in LMBs, outperforming state-of-the-art LiFSI-based electrolytes. Notably, LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) || Li batteries exhibit 80% capacity retention after 430 cycles, along with outstanding rate performance (2.35 mAh cm⁻² at 12 mA cm⁻²) under practical conditions (20 mg cm⁻² NCM811, 50 µm Li foil, and 5.6 mL Ah⁻¹ electrolyte). The rapid kinetics can be attributed to the efficient transport of lithium ions through both the bulk electrolyte and the electrode/electrolyte interphases. The work highlights the significance of low-cost LiNO₃ salt and presents an alternative pathway to achieving superior performance for lithium metal batteries under extreme conditions.