Intrinsically safe electrolyte boosting high reversibleZn anode for rechargeable batteries

Rechargeable Zn batteries (RZBs) have been one of the hot topics in the field of electrochemical power sources due to their low cost and non-toxicity. However, Zn anode is still a critical issue that seriously affects RZBs practical applications mainly due to its thermodynamic instability with aqueous electrolytes. To solve the inherent disadvantages of traditional electrolytes, it's necessary to develop highly stable and intrinsically safe electrolytes for long-cycle-life RZBs. Herein, the functionalized ionic liquid and urea-based safe organic solvents are adopted to adjust the electrochemical performances of Zn metal anodes, leading to high Columbic efficiency (CE) of over 99.4% along with long cycle life of over 1200 h at 2.0 mA cm−2, even survive at 5.0 mA cm−2 as well as the large areal capacity of 10 mAh cm−2, where interface derived from ionic liquid effectively accelerates the Zn nucleation, ensures smooth deposit and alleviates side reactions. The combination of organic electrolytes with multi-functional additives might pave the way to develop thermodynamically stable and intrinsically safe electrolytes for practical RZBs.