Shooting Three Birds with One Stone: The Regulation of Zn2+, H2O, and OH Kinetics for Stable Zn‐Metal Anodes with a Multifunctional Sieve

Abstract

AbstractZn‐metal anode for Zn ion battery (ZIB) suffers from multiple catastrophic issues (severe corrosion reaction, concomitant hydrogen evolution, and dendrite growth) that are always intricate and are inevitably interactional, setting up critical obstacle for application of ZIB. Herein, a multifunctional sieve (MS) consisting of inorganic nanolayers and organic molecule layers is proposed to solve these issues synchronously based on its trifunctional roles (accelerating Zn2+, repelling H2O, and binding OH). As a prototype, porous nano‐architecture MS composed of steric acid molecule layer and TiO2 nanosheets (derived from MXene) (SA@TiO2‐MS) is deliberately created on the surface of zinc anodes (Zn@SA@TiO2‐MS) employing in situ self‐assembly strategy. Theoretical calculations together with proof‐of‐experiment prove that SA@TiO2‐MS can alleviate the growth of Zn dendrites, mitigate hydrogen evolution, relieve corrosion reaction, via the acceleration of the Zn2+ diffusion, the repelling of H2O with hydrophobic SA layer, as well as the bonding of OH with TiO2 layer. As a result, Zn@SA@TiO2‐MS||Zn@SA@TiO2‐MS symmetric cell achieves a lifespan up to 1100 h at 5 mA cm−2. In addition, the full‐cell by pairing carbon‐cloth@MnO2 with Zn@SA@TiO2‐MS delivered capacity retention of 70.3% after 2000 cycles. This work proposes fundamentally a more comprehensive approach to balance the issues faced by Zn‐metal anode.