An Electrochemically Polymerized Protective Layer for Magnesium Metal Anode

Rechargeable magnesium (Mg) batteries are promising beyond Li-ion technologies due to their high volumetric capacity (3832 mAh cm −3 ) and natural abundance. Nonetheless, Mg metal anode is incompatible with most conventional electrolytes which leads the formation of an ionically passivating layer. also suffers from growth dendrites similar Li, causes failure cells. In this study, we electrochemically polymerized 1,3-dioxolane (DOL) form a thin 2+ -conducting elastomeric artificial solid electrolyte interphase (ASEI) layer by pretreating anodes. We found that protective ASEI enables excellent cyclability Mg-Mg symmetric cells at current density (0.5 mA -2 over 400 hours stable low overpotential (0.50 V vs. /Mg) without cell short-circuiting, while untreated pristine quickly failed. The significantly lowered impedance cells, proved its capability conducting ions. Comprehensive surface chemistry analysis was done X-ray photoelectron spectroscopy (XPS) showed mainly consists poly-DOL formed, along various salts instrumental conductance More importantly, component in elastomer well preserved post-cycling, contributed long-term voltage hysteresis pretreated as compared ones. Focused ion beam (FIB) – scanning electron microscopy (SEM) energy-dispersive (EDS) mapping generally uniform formed on roughly 200 µm thick able suppress after cycling for 0.03 density, rampant sphere-shaped anodes cycling. This first ever report successful electrochemical polymerization method effectively enhanced performance Figure 1