Electrochemical stability of Zn metal anode in N-methyl-2-pyrrolidone based non-aqueous electrolyte

Abstract

In search of cost-effective and safe energy storage systems, rechargeable Zn batteries offer huge promise due to their low cost and relatively high safety. However, their widespread commercialization goals are dented seriously by Zn dendrite growth and passivation resulting in poor cycle life and early cell failures. Herein, N-methyl-2-pyrrolidone (NMP) is adopted as a solvent for rechargeable Zn batteries which demonstrates highly thermodynamic stability with Zn metal anodes. Zn||Zn cells in NMP-electrolyte exhibit cycle life of over 4000 h at a current density of 0.5 mA cm−2 with a plating capacity of 2.5 mAh cm−2, along with high average CE of 99.52% and wide current densities ranging from 0.5 to 10.0 mA cm−2. Moreover, stable Zn||Zn cycling at 50 °C further marks NMP as a potentially impressive non-aqueous electrolyte for high-temperature Zn batteries. Zn||α-CrMnO2 battery is also initially investigated to prove the compatibility of NMP within full cell and demonstrate its application potential for practical rechargeable Zn batteries.