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

Rational surface engineering of 2D nanoarchitectures-based electrode materials is crucial as it may enable fast ion transport, abundant-surfacecontrolled 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.