Spatio-dipolar synergy modulated interfacial molecular bridge for calendar aging resistant aqueous zinc-ion batteries

Abstract Short calendar-aging life and interfacial degradation hinder the applications of aqueous Zn-ion batteries. Herein, trimorpholinophosphine-oxide (TPO), featuring high Topological Polar Surface Area (TPSA), is introduced as an electrolyte additive that modulates interfacial ions via steric-dipolar synergism. Specifically, the topological polarity of TPO facilitates Zn2+ coordination and strong surface adsorption, creating migration channels within solvation-interfacial networks. Moreover, the steric hindrance of TPO disrupts the solvation sheath of Zn2+, forming H3O+-repelled layers. Consequently, TPO-containing cells achieve an exceptional average Coulombic efficiency (CE) of 99.91% and operate steadily at ultrahigh current densities (280 mA cm−2). At -20°C, TPO-containing cells retain 177 mAh g⁻1 after 6000 cycles, yet additive-free cells fail after 1400 cycles (84 mAh g⁻1). Most importantly, TPO-containing cells maintain high CE exceeding 95% over a superior 2500 h under intermittent calendar-aging, far exceeding the 72 h of additive-free cells. This work offers molecular-level insights into TPSA-induced steric-dipole synergism for ultra-stable batteries.