Engineering 2D Nanofluidic Li‐Ion Transport Channels for Superior Electrochemical Energy Storage

Abstract Rational surface engineering of 2D nanoarchitectures‐based electrode materials is crucial as it may enable fast ion transport, abundant‐surface‐controlled energy storage, long‐term structural integrity, and high‐rate cycling performance. Here we developed the stacked ultrathin Co₃O₄ nanosheets with surface functionalization (SUCNs‐SF) converted from layered hydroxides with inheritance of included anion groups (OH⁻, NO₃⁻, CO₃²⁻). Such stacked structure establishes 2D nanofluidic channels offering extra lithium storage sites, accelerated Li‐ion transport, and sufficient buffering space for volume change during electrochemical processes. Tested as an anode material, this unique nanoarchitecture delivers high specific capacity (1230 and 1011 mAh g⁻¹ at 0.2 and 1 A g⁻¹, respectively), excellent rate performance, and long cycle capability (1500 cycles at 5 A g⁻¹). The demonstrated advantageous features by constructing 2D nanochannels in nonlayered materials may open up possibilities for designing high‐power lithium ion batteries.