Enhancing the Cathode/Electrolyte Interface in Ni-Rich Lithium-Ion Batteries Through Homogeneous Oxynitridation Enabled by NO3− Dominated Clusters

To meet the demand for higher energy density in lithium-ion batteries, extensive research has focused on advanced cathodes and metallic lithium anodes. However, Ni-rich cathodes suffer from the inactive phase-transition and side reactions at the cathode-electrolyte interfaces (CEI). In this study, we propose a novel approach to enhance the solubility of LiNO3 in carbonate electrolyte systems using a local high-concentrated addition strategy with triethyl phosphate as a co-solvent. Rather than the traditional solvent-dominated solvation clusters, the NO3− dominated electrolyte is examined to elucidate unique complexation phenomena. Two distinct clusters in NO3− dominated electrolyte arising from as a consequence of intramolecular interactions intrinsic to the constituents. This promotes the formation of a homogeneous oxynitride interphase and facilitates more expeditious lithium ion diffusion kinetics. Hence, the less stress fragmentation and irreversible phase transformation occur on the cathode surface with the homogeneous oxynitridation interface. This innovative design enables efficient cycling of the Li || NCM811 cell, offering a promising strategy to improve lithium-ion batteries performance.