Ultrafast Lithium‐Ion Transport Engineered by Nanoconfinement Effect

Abstract Amid the burgeoning demand for electrochemical energy storage and neuromorphic computing, fast ion transport behavior has attracted widespread attention at both fundamental and practical levels. Here, based on the nanoconfined channel of graphene oxide laminar membranes (GOLMs), the lithium ionic conductivity typically exceeding 10 2 mS cm −1 is realized, one to three orders of magnitude higher than traditional liquid or solid lithium‐ion electrolyte. Specifically, the nanoconfined lithium hexafluorophosphate (LiPF 6 )‐ethylene carbonate (EC)/ dimethyl carbonate (DMC) electrolyte demonstrates the ionic conductivity of 170 mS cm −1 , outperforming the bulk counterpart by ≈16 fold. At the ultralow temperature of −60 °C, the nanoconfined electrolyte also maintains a practically useful conductivity of 11 mS cm −1 . Furthermore, the in situ experimental and theoretical framework enables to attribute the enhanced ionic conductivity to the layer‐by‐layer cations and anions distribution induced by high surface charge and nanoconfinement effects in GO nanochannels. More importantly, integrating such rapid lithium‐ion transport nanochannel into the LiFePO 4 (LFP) cathode significantly improves the high‐rate and long‐cycle performance of lithium batteries. These results exhibit the convention‐breaking ionic conductivity of nanoconfined electrolytes, inspiring the development of ultrafast ion diffusion pathways based on 2D nanoconfined channels for efficient energy storage applications.