Zincophilic, Green, Non‐Toxic Additives Modulate Lean‐Water Inner Helmholtz Layer for Enhanced Stability of Zinc Anodes

The structural modulation of the inner Helmholtz layer is crucial to enhance the cycling stability of Zn anode interface. A water‐rich inner Helmholtz layer normally induces uncontrollable zinc dendrites, hydrogen evolution and corrosion, severely compromising the cycle life of the zinc anode. Therefore, in this work, green and non‐toxic dipropylene glycol dimethyl ether (DMM) is used as an additive to remodel the inner Helmholtz layer. Both experimental and computational results show that DMM is zincophilic and can preferential adsorb on the zinc surface for the occupation of the inner Helmholtz layer. Meanwhile, DMM contains two hydrophobic methyl groups, which can repel water molecules remaining after solvent removal, and build a lean‐water inner Helmholtz layer to avoid continuous contact between water molecules and zinc anode. The quartz crystal microbalance with dissipation test intuitively and accurately reflected the adsorption behavior of DMM on the surface of zinc anode, and realized the leap from qualitative analysis to quantitative analysis. The Zn//Zn symmetric cells with DMM electrolytes have a stable cycle life of over 1100 cycles at 2 mA cm −2 and 0.5 mAh cm −2 . In addition, Zn//PANI cell with DMM electrolyte can maintain 90% capacity retention over 1000 cycles at 1 A g −1 .