Quasi-Solid-State Zn-Ion Batteries Based on Sol-Gel Transition and in Situ Electrodeposition of MnO₂

Zinc-ion batteries (ZIBs) have received much attention recently, because they are low-cost and environmentally friendly. In addition, ZIBs can be safer than lithium-ion batteries (LIBs) if issues, such as dendrite formation, side reactions, and hydrogen evolution, are resolved. Overcoming these challenges is crucial for the large-scale commercialization of ZIBs. In this article, Kevlar derivatized Aramid nanofiber combined with poly(vinyl alcohol) hydrogel was used to prevent the Zn dendrite growth and side reactions and increase the cyclability of the cells. A fast and simple method that involves sol-gel transition and in situ electrodeposition of the MnO₂ cathode was developed to fabricate quasi-solid-state ZIB cells with an initial capacity of 5.2 and 3.3 mA h after 900 cycles at 10C. In addition, we have optimized the assembling process of ZIBs pouch cells by taking advantage of sol-gel transition and eliminating the conventional complex slurry-casting-drying steps. This work paves the way to efficiently assemble ZIB pouch cells with excellent rate performance and cycling stability.