Aqueous Zn metal batteries hold promising prospect for stationary energy storage technology, but the annoying dendrite growth with low cycling efficiency of Zn metal anodes caused by the unstable Zn-electrolyte...

Zn metal has received immense interest as a promising anode of rechargeable aqueous batteries for grid-scale energy storage. Nevertheless, the uncontrollable dendrite growth and surface parasitic reactions greatly retard its practical implementation. Herein, we demonstrate a seamless and multifunctional metal−organic framework (MOF) interphase for building corrosion-free and dendrite-free Zn anodes. The on-site coordinated MOF interphase with 3D open framework structure could function as a highly zincophilic mediator and ion sifter that synergistically induces fast and uniform Zn nucleation/deposition. In addition, the surface corrosion and hydrogen evolution are significantly suppressed by the interface shielding of the seamless interphase. An ultrastable Zn plating/stripping is achieved with elevated Coulombic efficiency of 99.2% over 1000 cycles and prolonged lifetime of 1100 h at 10 mA cm −2 with a high cumulative plated capacity of 5.5 Ah cm −2 . Moreover, the modified Zn anode assures the MnO 2 -based full cells with superior rate and cycling performance.

Hard carbons as a kind of nongraphitized amorphous carbon have been recognized as potential anode materials for sodium-ion batteries (SIBs) due to its large interlayer spacing. However, the issues in terms of onerous synthetic procedure and elusive working mechanism remains critical bottlenecks for practical implement. Herein, we report a facile production of tubular hard carbon through direct carbonization of platanus flosses (FHC) for the first time. Through optimizing the pyrolysis temperatures, the FHC obtained at 1300 °C possesses a key balance between the interlayer spacing and surface area, which can maintain the substantial active sites as well as reduce the irreversible sodium storage. Accordingly, it can deliver a reversible capacity of 324.6 mAh g–1 with a high initial Coulombic efficiency of 80%, superb rate property of 107.2 mAh g–1 at 2 A g–1, and long operating stability over 1000 cycles. Furthermore, the in situ Raman spectroscopic studies certify that sodium ions are stored in FHC following the “adsorption–insertion” mechanism. Our study could provide a promising route for large-scale development of the biomass-derived carbonaceous anodes for high-performance SIBs.

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