Adsorption-induced Dual-layer Solid Electrolyte Interface Toward High-Reversible Zn Anode

Abstract

Aqueous zinc-ion batteries (AZIBs) are promising candidates for grid-scale energy storage due to their low cost and high safety, but display limited application due to severe parasitic reactions and dendrite growth on the zinc (Zn) anode. Herein, a unique adsorption-induced solid electrolyte interphase (SEI) formation mechanism is proposed using trace amount of 2-pyrrolidinone (PD), synergistically addressing the Zn dendrite growth, corrosion and hydrogen evolution reaction (HER). Multidimensional theoretical and experimental studies reveal that PD preferentially adsorbs on the Zn anode via strong interaction between its amino/carbonyl groups and Zn atoms. This interfacial coordination can modify the chemical environment of PD and thereby triggering its electrochemical decomposition to in situ generate a dual-layer organic-inorganic SEI on the Zn anode. As a result, Zn‖Zn symmetric cells with PD-containing electrolyte exhibit an ultra-long cycling lifespan of >1600 hours at 1 mA cm-2 and 1 mAh cm-2. Zn‖Cu asymmetric cells exhibit a high average Coulombic efficiency of 99.7% over 3000 cycles at 5 mA cm-2 and 1 mAh cm-2. Full batteries paired with polyaniline (PANI) and NaV3O8·1.5H2O (NVO) cathodes also demonstrate exceptional capacity retention and cycle life (95% after 1200 cycles for Zn‖PANI at 1 A g-1 and 71.1% after 300 cycles for Zn‖NVO at 5 A g-1). This work provides a paradigm for in situ construction of efficient hybrid SEI to realize highly reversible zinc anode.