Unshared Pair Electrons of Zincophilic Lewis Base Enable Long-life Zn Anodes under Three High Conditions

The hydrogen evolution and dendrite issues are the notorious culprits of the limited lifespan and Coulombic efficiency (CE) of Zn anodes, particularly at harsh test conditions. Herein, considering the Lewis acidic feature of Zn2+, abundant unshared pair electrons of zincophilic Lewis bases are proposed as decent electrolyte additives to stabilize Zn anodes at Three High conditions (high depth of discharge, high areal capacity and high current). The unshared pair electrons can remove H2O from Zn2+ solvated sheaths and confine the activity of H2O by breaking its hydrogen bonding network. The combination of these factors effectively restricts H2O-involved side reactions and enables dendrite-free Zn deposition, even at harsh conditions. The effectiveness of this strategy is fully proved by a series of Lewis base molecules. Noticeably, the Zn||Zn cell with an area of 20 cm(2), using DMF-containing electrolyte can be stably cycled over 1000 h at 60 % DOD, with a 100 % CE.

Automated summary

This study proposes the use of zincophilic Lewis bases as electrolyte additives to stabilize Zn anodes under harsh test conditions by removing H2O from the solvated Zn2+ sheaths and limiting its activity. The combination of these factors effectively restrains water-involved side reactions and enables dendrite-free Zn deposition, even at high demand conditions.