Tailoring Local Electrolyte Solvation Structure via a Mesoporous Molecular Sieve for Dendrite‐Free Zinc Batteries

Abstract Aqueous zinc‐ion batteries (ZIBs) are low cost with a promising theoretical capacity and inherent safety, and thus have drawn increasing attention as prospective energy storage devices in large‐scale energy storage systems. However, severe dendrite growth and side reaction problems hinder the practical application of ZIBs. Here, molecular sieves with ordered mesoporous channels are constructed to tailor the local electrolyte solvation structure on the zinc surface. Different high‐concentration solvation structures can be realized by adjusting the pore diameter of the molecular sieve, and the optimal pore geometry is a mesoporous channel with a diameter of 2.5 nm that induces the formation of a locally concentrated electrolyte and affords a lower Zn 2+ de‐solvation energy in Mobil composition of matter number 41 (MCM41). The resulting MCM41‐Zn anode exhibits high cycling stability for Zn stripping/plating under different current densities (over 1800 h at 1 mA cm –2 , 1 mAh cm –2 , and 2200 h at 5 mA cm –2 , 1 mAh cm –2 ). Moreover, the CaV 8 O 20 ·nH 2 O//MCM41‐Zn full cell shows a high capacity of 274.2 mAh g −1 and a long lifespan (no capacity decay after 1000 cycles at 4 A g –1 ).