Semi-Immobilized Ionic Liquid Regulator with Fast Kinetics toward Highly Stable Zinc Anode under-35 to 60 °C

Aqueous zinc ion batteries (ZIBs) have been extensively investigated as a next-generation energy storage system due to their high safety and low cost. However, the critical issues of irregular dendrite growth and intricate side reactions severely restrict the further industrialization of ZIBs. Here, a strategy to fabricate a semi-immobilized ionic liquid interface layer is proposed to protect the Zn anode over a wide temperature range from -35 to 60 degrees C. The immobilized SiO2@cation can form high conjugate racks that can regulate the Zn2+ concentration gradient and self-polarizing electric field to guarantee uniform nucleation and planar deposition; the free anions of the ILs can weaken the hydrogen bonds of the water to promote rapid Zn2+ desolvation and accelerate ion-transport kinetics simultaneously. Because of these unique advantages, the cycling performance of the symmetric Zn batteries is greatly enhanced, evidenced by a cycling life of 1800 h at 20 mA cm(-2), and a cycle lifespan of 2000 h under a wide temperature window from -35 to 60 degrees C. The efficiency of this semi-immobilizing strategy is well demonstrated in various full cells including pouch cells, showing high performance at large current (20 A g(-1)) and wide temperatures with extra-long cycles up to 80 000 cycles.

Automated summary

This study proposes a strategy to fabricate a semi-immobilized ionic liquid interface layer in order to address the issues of irregular dendrite growth and side reactions in aqueous zinc ion batteries (ZIBs). By using immobilized SiO2@cation and free anions, the Zn anode is protected and achieves stable cycling performance over a wide temperature range.