Porous Attapulgite Interfaces with Nanochannels That Enable Dendrite-Free Aqueous Zinc Ion Batteries

Aqueous zinc ion batteries (AZIBs) are promising for energy storage due to their high specific capacity and high safety. Unfortunately, uneven Zn dendrite growth and corrosion limit their further application. Herein, we demonstrate a cost-effective porous attapulgite nanorod protective layer to endow Zn anodes with dendrite-free Zn stripping/plating. The porous attapulgite coating serves as an artificial protective layer, which not only provides multiple nanochannels to homogenize the Zn2+ flux for uniform Zn stripping/plating but also improves the hydrophilicity favoring electrolyte infiltration and fast Zn2+ transport. In consequence, the ATP-Zn anode displays significantly reduced charge transfer resistance. Symmetric cells based on the ATP-Zn anode exhibit long cycling stability of 1600 h with a small voltage hysteresis of 40 mV at 0.25 mA cm–2, much better than that of the bare Zn anode. The ATP-Zn anode also displays a high Coulombic efficiency of 98% and a lower nucleation overpotential in half-cells. When compared with the typical β-MnO2 cathode, the ATP-Zn//MnO2 cell exhibits good cyclic stability. The reversible capacity of the ATP-Zn//MnO2 cell is 210 mAh g–1 after 300 cycles at 1C, while the capacity of the Zn//MnO2 cell is only 107 mAh g–1. This work provides an eco-friendly and facile strategy to upgrade the electrochemical stability of AZIBs.