Dilemma of Low-Cost Filter Paper as Separator: Toughen Its Wet Strength for Robust Aqueous Zinc-Ion Batteries

Abstract

The industrialization of aqueous zinc-ion batteries (AZIBs) is hampered by poor-performance separators. Filter paper (FP), with mature production processes and low prices, has potential as a separator. However, its swelling and decline of mechanical durability in aqueous environments make it easily punctured by dendrites. In response, wet strength promotion is proposed to toughen FP for robust AZIBs, termed wet-strengthened FP (WSFP). Due to the self-cross-linking network formed on cellulose fibers, water molecules are prevented from easily permeating and disrupting the hydrogen bonds between cellulose molecules. Moreover, the positively charged network can anchor SO 4 2− , thus increasing the Zn 2+ transference number and facilitating uniform zinc deposition. Surprisingly, the half and full cells with the WSFP separator present much more stable cycling than untreated FP and glass fiber (GF) separators. These results suggest that robust and low-cost WSFP separators provide a new avenue for the development of high-performance AZIBs with potential for commercialization.

A Multifunctional Additive Based on the Cation–Anion Synergistic Effect for Highly Stable Zinc Metal Anodes

“…In recent years, amidst the backdrop of global green development and energy scarcity, there is an urgency to develop green energy storage solutions characterized by robust safety, heightened reliability, elevated energy density, and cost-effectiveness. − Researchers have extensively investigated aqueous zinc-ion batteries (AZBs) owing to their low toxicity, abundant global reserves, and high theoretical capacity (820 mAh g –1 ; 5855 mAh cm –3 ), as well as nonflammable and high ionic conductivity of aqueous electrolyte. − Nevertheless, Zn metal anodes have faced a series of challenges related to the rampant zinc dendrite growth, corrosion, and hydrogen evolution reaction (HER). The “tip effect” continuously attracts more Zn 2+ to the initial zinc nuclei, resulting in the growth of dendrites that can ultimately breach the diaphragm and compromise battery integrity. , However, with the deprotonation of larger amounts of free water, the water-induced HER would lead to the gas generation issue and competed side reactions with zinc deposition, which have severely hindered the application of AZBs.…”