Rational design of dual-function zwitterionic cellulose poly(ionic liquid)s enabling ultralong-cycling dendrite-free zinc anodes

A zwitterionic cellulose poly(ionic liquid) additive enables electrostatic shielding and preferential adsorption to stabilize Zn anodes. • Zn||Cu half-cells deliver 99.75% average CE over 2,792 cycles at 10 mA cm -2 . • Zn||Zn symmetric cells achieve an ultralong lifespan of 3,160 h at 0.5 mA cm -2 . • Zn||NVO full cells retain 82.4% capacity after 500 cycles at 1 A g -1 and suppress vanadium dissolution. Aqueous zinc-ion batteries (AZIBs) face formidable barriers including uncontrolled dendrite growth, severe corrosion, hydrogen evolution, and inhomogeneous Zn 2+ deposition. To overcome these challenges, this work develops an innovative zwitterionic cellulose poly(ionic liquid)s (ZC-PILs) electrolyte additive leveraging the DBU/CO 2 /DMSO solvent system. The ZC-PILs synergistically combines electrostatic shielding from [Mim] + moieties and self-adsorption of −COOH groups to stabilize Zn anodes. Unprecedented electrochemical performance is demonstrated by an average CE of 99.75% over 2792 cycles for Zn||Cu cells at 10 mA cm −2 and stable operation for 3160 h for Zn||Zn symmetric cells at 0.5 mA cm −2 with a capacity of 0.5 mAh cm −2 . Interfacial and electrochemical analyses reveal preferential Zn(002) deposition, the formation of ZnS-ZnF 2 -rich SEI layers, and improved electrochemical stability of NH 4 V 4 O 10 cathodes in ZC-PILs-containing electrolytes. Consequently, Zn||NVO full cells retain 82.4% capacity after 500 cycles at 1 A g −1 with 92.94% CE and minimal self-discharge. This work demonstrates a multifunctional additive strategy for suppressing dendrite growth and improving the stability of zinc batteries. Cellulose-based zwitterionic poly(ionic liquid)s (ZC-PILs) simultaneously regulate Zn 2+ transport and the Zn/electrolyte interface through imidazolium-mediated electrostatic modulation and carboxyl-group-assisted preferential adsorption. This dual-function interfacial regulation homogenizes Zn 2+ flux, suppresses parasitic reactions and dendrite growth, and enables highly reversible, ultralong-cycling Zn anodes. Download: Download high-res image (215KB) Download: Download full-size image