3D-Polyacrylamide/Ti-MXene: A Newer Hybrid Hydrogel Electrolyte Featuring High Mechanical Strength and Durability for Flexible Aqueous Zinc-Ion Batteries

The utilization of hydrogel (HG) electrolytes for aqueous zinc-ion batteries is a new emerging technology for flexible and wearable electronics owing to their eco-friendliness, low cost, high safety, and ease of operation. In comparison with solid electrolytes, the hydrogel electrolyte (HGE) carries an annexation of the individualities of both solid and liquid electrolytes in terms of mechanical strength and ionic conductivity. However, it is still a technical hitch to achieve hydrogel electrolytes that comply with all of the necessities for developing a high-performance zinc-ion battery. Herein, a newer type of polymer-inorganic-based hybrid hydrogel electrolyte (HHGE) of polyacrylamide (PAM)/Ti-MXene is developed for aqueous zinc-ion batteries to address the aforementioned concerns. Among different wt % values of Ti-MXene-incorporated PAM, PAM/Ti-MXene (0.1 wt %) HHGE shows a higher ionic conductivity of 25.27 mS cm –1 with an electrochemical stability window (ESW) of ∼2.7 V. Additionally, the as-fabricated Zn // V 2 O 5 –CNT battery shows a higher initial capacity of 192 mAh g –1 at 0.05 Ag –1 with a Coulombic efficiency of 100%.