Paschen–Back effect modulation of SO42- hydration in magnetized electrolyte toward dendrite-free Zn-ion batteries
Xiayan Yao, Zhi Wang, Jianwei Guo, Guoyu Qian, Hongchen Wang, Xuzhong Gong, Dong Wang
Abstract
Tuning anionic solvation structures and dynamic processes at solid–liquid interfaces is critical yet challenging for stabilizing Zn metal negative electrodes in Zn-ion batteries, particularly due to the issue of dendrite formation and hydrogen evolution reaction. Here, we show that highly hydrated SO42- can be effectively modulated under a strong magnetic field via the Paschen–Back effect on O-H vibrations, which reorients individual water molecules to manipulate Zn2+ solvation and protonated water clusters (H3O+). Molecular dynamics simulations and in situ Raman spectroscopy reveal that the hydrated SO42-–H2O complexes promote Zn2+ nucleation and deposition on the (002) plane, with preferential oxygen adsorption inhibiting two-dimensional Zn2+ diffusion. Moreover, magnetizing the electrolyte disrupts the Grotthuss proton-transfer pathway, suppressing H2 evolution and further reducing dendrite formation. By employing inexpensive permanent magnets without external power, this magnetization strategy offers a practical, energy-efficient route to enhance both the stability and performance of zinc-based rechargeable batteries. Dendrite growth and hydrogen evolution limit the stability of aqueous zinc metal batteries. Here, authors use a magnetic field to tune ion solvation and proton transfer, enabling uniform Zn deposition and suppressing side reactions, offering a simple strategy to boost battery performance.