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

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 solid electrolyte interphase. 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 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||LiNi0.8Co0.1Mn0.1O2 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.