Design of a permselective interface for highly stable Zn electrodeposition

In aqueous electrolytes, the deterioration of Zn electrodes is mainly due to the electrolyte species (e.g., H2O, Zn2+, SO42-, etc.) involved side reactions happened at the Zn|electrolyte interface (ZEI). Here, we design a permselective polyelectrolyte (PPE) that is rich in hydrophobic ethylhexyl and anion-blocking sulfonate (-SO3-) groups for Zn electrodes. During Zn electrodeposition, the PPE coating serves as a screener to suppress the transportation of undesired electrolyte species (e.g., H2O and SO42-) while homogenizing the Zn-ion flux. The as -designed PPE significantly suppresses the side reactions and prolongs the cycling life of the Zn electrodes. Even with a PPE layer as thin as similar to 220 nm, the protected Zn electrode delivers an exceptional stability of > 3400 h at an areal capacity of 2 mAh cm(-2) and > 1200 h at a higher capacity of 10 mAh cm-2, superior to those of the control cells.

Automated summary

By designing a polyelectrolyte coating that is rich in hydrophobic and anion-blocking groups, undesired side reactions at the zinc electrode|electrolyte interface can be suppressed, leading to a prolonged cycling life of the zinc electrodes.