Uniform Zn2+ distribution and deposition regulated by ultrathin hydroxyl-rich silica ion sieve in zinc metal anodes

Recently, the design of zinc metal anodes with high Coulombic efficiency and long lifespan remains a huge challenge due to the occurrence of uncontrollable dendrites growth and side reactions. Herein, a hydroxyl-decorated in-plane micro-mesoporous silica nanosheet is reported as ion sieve which can effectively regulate the plating/stripping behavior of zinc ion, ensuring uniform Zn2+ distribution and deposition. According to the COMSOL simulations and DFT calculations, the well-ordered micro-mesopores serves as the ion channels to homogenize the Zn-ion flux distribution and the hydroxyl group decreases the affinity of ion sieve to Zn which is beneficial to the planar Zn deposition. Thanks to the presence of the silica ion sieve, the assembled Zn//Zn cells demonstrates an extremely long cycle lifespan of over 3400 and 2500 h at 1 and 10 mA cm−2 respectively, which is approximately 25 and 20 times that of bare Zn//Zn cells. Impressively, the constructed Zn//NaV3O8·1.5H2O full cells and Zn//AC hybrid capacitors operates steadily for more than 1500 and 8300 (capacity retention of 100%) cycles even under high cathode loading of 5.8 and 31 mg cm−2, respectively. Moreover, this strategy can be conveniently extended to lithium metal anodes, suggesting its high versatility in inhibiting dendrite growth in metal anodes.