Ultra‐Stable Zn Anode Enabled by Fiber‐Directed Ion Migration Using Mass‐Producible Separator

Abstract

Aqueous zinc‐ion battery (AZB) is a promising candidate for next‐generation energy storage owing to inherent safety and low cost. However, AZBs are currently plagued by Zn dendrite growth and undesirable side‐reactions, leading to poor cycling stability and premature failure. To restrain the uncontrollable Zn growth, a unique separator is developed based on polyacrylonitrile/graphene oxide (abbreviated as PG) composite nanofibers, which contain abundance of zincophilicity functional groups to regulate the migration and distribution of Zn2+ ions in the separator. It is demonstrated that the cyano ligands on PG not only facilitate the dehydration of solvated Zn2+ ions prior to deposition, but also form fast lanes to enable homogenous scattering of deposition spots. Benefiting from these features, the PG separator offers a high ionic conductivity of 7.69 mS cm‐1 and a transference number of 0.74 for Zn2+. The Zn||Zn symmetrical cells with PG separators achieve an ultra‐stable cycle life over 13 000 h. Zn||Zn0.27V2O5 full batteries with PG separators retain 71.5% of the original capacity after 2800 cycles at a high current density of 2 A g‐1. This study offers future research directions toward the design of multifunctional separators to overcome the limits of Zn metal anode in AZBs.

Multi‐Healable, Mechanically Durable Double Cross‐Linked Polyacrylamide Electrolyte Incorporating Hydrophobic Interactions for Dendrite‐Free Flexible Zinc‐Ion Batteries

“…Compared with many previously reported hydrogels, the PAAm‐O 110 ‐B hydrogel electrolyte has a higher $${t}_{{\mathrm{Zn}}^{2 + }}$$ value, suggesting favorable Zn 2+ migration in the PAAm‐O 110 ‐B hydrogel electrolyte (Figure 3i). [ 27,28 ] The enhanced ionic conductivity and transference number can be attributed to these hydrophobic segments in the hydrogel which act as physical cross‐linkers to form a 3D structure in the aqueous solution and eventually lead to more porosity. Besides, the PAAm‐O‐B hydrogel electrolyte possesses more accessible NH 2 and CO groups in the skeleton to interact with Zn 2+ ions to help their transport in electrolyte.…”

“…g) Nyquist plots before and after potentiostatic polarization and h) chronoamperometric curve of PAAm-O 110 -B hydrogel electrolyte. i) Comparison of the t Zn 2+ of the PAAm-O 110 -B hydrogel electrolyte (at room temperature) with other works (GF: glass fibers; CF: cellulose fibers; PH SPE: PVDF-HFP solid polymer electrolyte; PH/MXene SPE: PVDF-HFP/MXene solid polymer electrolyte) [27,28].…”

A Functional Janus Ag Nanowires/Bacterial Cellulose Separator for High‐Performance Dendrite‐Free Zinc Anode Under Harsh Conditions

“…BC separators are easily prepared through industrial methods. [31] Consequently, BC has been studied as a possible candidate to generate ultrathin porous functional separators with superior mechanical strength. [32][33][34][35][36] Despite these advantages, BC separators have low porosity given the strong interactions within the fibrils, which hinders quick ionic transportation.…”

Regulating the Water Molecular in the Solvation Structure for Stable Zinc Metal Batteries

“…[17][18][19] However, since the Zn anode experiences large and uneven volume variation during the repeated plating/stripping, the 3D structure of Zn anode and artificial interphase on the Zn surface would be unavoidably destroyed during the cycling. [20,21] Zhou et al developed a Metal-organic frameworks functionalized glass fiber separator (UiO-66-GF), which could accelerate the transport of charge carriers and provide a uniform electric field distribution. Besides, Zinc anode demonstrates preferential orientation of (002) plane under the control of UiO-66-GF, which effectively inhibits dendrites.…”