Lamellar Regulation for Fast and Reversible Zinc‐Ion Transport in Water‐Rich Hydrogels for Aqueous Zinc‐Ion Batteries

ABSTRACT

The trade‐off between stability and efficiency has critically impeded the widespread applications of aqueous zinc‐ion batteries (ZIBs). Hydrogel electrolytes typically require a high content of water to achieve desirable ionic conductivities, which still led to stability issues in ZIBs. Herein, a simple approach is proposed to simultaneously improve the Zinc‐ion (Zn ²⁺ ) transportation and stability of water‐rich hydrogels for ZIBs by constructing lamellar regulation of lyotropic liquid crystals (LLCs). Lamellar water‐rich hydrogels with a high liquid content of 82% are prepared by polymerization of acrylamide in lamellar LLC solutions, which were formed by self‐assembly of amphiphilic sodium dodecyl sulfate (SDS) in ZnSO ₄ solutions. The self‐assembly of SDS regulates the ZnSO ₄ solutions within the lamellar LLC nanostructures. The lamellar regulation enables fast and reversible Zn ²⁺ transport in hydrogels and suppress the side reactions at Zn/hydrogel interfaces, which synergistically boost the efficiency and stability of ZIBs. The lamellar water‐rich hydrogel electrolytes show superior charge/discharge capacities and robust cyclic performance in separator‐free V ₂ O ₅ //Zn pouch cells comparing to corresponding conventional water‐rich hydrogels and micellar water‐rich hydrogels. The work here paves new way of introducing lamellar LLC nanostructures for developing high‐performance hydrogel electrolytes for superior ZIBs.