Dielectric additive induced weak Li solvation towards stabilized solid electrolyte interface for 4.6 V lithium metal batteries

Abstract

Developing stable electrode-electrolyte interphases on Li metal anode (LMA) and high voltage cathode is crucial for producing durable Li metal batteries. Electrolyte engineering has been regarded as an efficient way to in-situ construct stable and robust interphase. Herein, a dielectric electrolyte system is proposed by introducing LiNbO₃ nanoparticles to liquid carbonate-based electrolyte for regulating Li⁺ solvation structure, and thus inducing stable inorganic-rich SEI. Moreover, these dielectric nano LiNbO₃ additives can regulate the Li⁺ flux through their build-in electric field to guide dendrite free Li deposition. These multi-functional features of LiNbO₃ (LNO) allow for exceptional cyclic performance in both symmetric cell configuration (3300 h at 0.5 mA cm⁻² and 1 mA h cm⁻²) and Li||LiNi_0.8Co_0.1Mn_0.1O₂ half-cell charged at 4.6 V with capacity retention of 80% over 200 cycles. These results demonstrate great potential of dielectric electrolyte on improving the performance of lithium metal batteries.