The performance of aqueous Zn ion batteries (AZIBs) is highly dependent on inner Helmholtz plane (IHP) chemistry. Notorious parasitic reactions containing hydrogen evolution reactions (HER) and Zn dendrites both originate from abundant free H2O and random Zn deposition inside active IHP. Here, we report a universal high donor number (DN) additive pyridine (Py) with only 1 vol. % addition (Py‐to‐H2O volume ratio), for regulating molecule distribution inside IHP. Density functional theory (DFT) calculations and molecular dynamics (MD) simulation verify that incorporated Py additive could tailor Zn2+ solvation sheath and exclude H2O molecules from IHP effectively, which is in favor of preventing H2O decomposition. Consequently, even at extreme conditions such as high depth of discharge (DOD) of 80 %, the symmetric cell based on Py additive can sustain approximately 500 h long‐term stability. This efficient strategy with high DN additives furnishes a promising direction for designing novel electrolytes and promoting the practical application of AZIBs, despite inevitably introducing trace organic additives.

Aqueous Zn‐ion batteries (ZIBs) have emerged as a promising energy supply for next‐generation wearable electronics, yet they are still impeded by the notorious growth of zinc dendrite and uncontrollable side reaction. While the rational design of electrolyte composition or separator decoration can effectively restrain zinc dendrite growth, synchronously regulating the interfacial electrochemical performance by tackling the physical delamination venture between electrode and electrolyte remains a major obstacle for high‐performance wearable aqueous ZIB. Herein, a category of hybrid biogel electrolyte containing carrageenan and wool keratin (CWK) is put forward to regulate the interfacial electrochemistry in aqueous ZIB. Systematic electrochemical kinetics analyses and ex situ scanning electrochemical microscopy (SECM) characterizations achieve comprehensive understanding of the keratin enhanced interfacial Zn2+ redox reaction. Thanks to the keratin triggered selective ion permeability, the as‐designed CWK hybrid biogel electrolyte manifests a promoted Zn2+ transference number and excellent reversibility of Zn plating/stripping and outstanding Zn utilization (average Coulombic efficiency ≈98%). More impressively, the CWK hybrid biogel electrolyte also demonstrates cathode side‐reaction depression and strengthened interfacial adhesion while assembled into a quasi‐solid‐state flexible ZIB. This work offers a strategy to synchronously solve concurrent challenges for both of Zn anode and cathode toward realistic wearable aqueous ZIB.

Aqueous Zn-ion hybrid capacitors (ZIHCs) present prominent potentials in flexible wearable electronics application scenarios due to their inherent high safety and low cost. Simultaneously, volumetric energy density is one of the crucial parameters to determine the lifespan of the wearable electronics, in which lightweight and miniaturization is a cardinal prerequisite for realistic application. In this work, an aqueous ZIHC is constructed by harmonizing interlayer spacing of the laminate graphene film and Zn-ion solvation structure to improve the electrode space utilization. Laminate graphene film interspacing has been customized in the range of 0.72-0.81 nm via regulating the ratio of crumple graphene mediator, thereby optimizing the transport kinetics of large size hydrated Zn ions. Zn-ion solvation structure is further tailored by introducing ZnCl 2 electrolyte salt to accouple such regulated laminar ionic transport channel. In a result, the thusderived ZIHC demonstrates an ultralong cycling lifespan of 100 000 cycles (93.9% capacitance retention), a preeminent volumetric capacitance (235.4 F cm −3 ), and a remarkable specific area capacitance contribution (C ssa ≈ 72 µF cm −2 ). Quasisolid-state ZIHC is assembled with ZnCl 2 solution-filled polyacrylamide gel electrolyte to concurrently achieve a superior areal capacitance of 1227 mF cm −2 and great mechanical flexibility toward practical wearable application.

Despite conspicuous merits of Zn metal anodes, the commercialization is still handicapped by rampant dendrite formation and notorious side reaction. Manipulating the nucleation mode and deposition orientation of Zn is a key to rendering stabilized Zn anodes. Here, a dual electrolyte additive strategy is put forward via the direct cooperation of xylitol (XY) and graphene oxide (GO) species into typical zinc sulfate electrolyte. As verified by molecular dynamics simulations, the incorporated XY molecules could regulate the solvation structure of Zn2+, thus inhibiting hydrogen evolution and side reactions. The self‐assembled GO layer is in favor of facilitating the desolvation process to accelerate reaction kinetics. Progressive nucleation and orientational deposition can be realized under the synergistic modulation, enabling a dense and uniform Zn deposition. Consequently, symmetric cell based on dual additives harvests a highly reversible cycling of 5600 h at 1.0 mA cm−2/1.0 mAh cm−2.

receiving great attention for serving as power source of wearable electronics. [1] 1D fiber batteries can be directly woven into commercial textiles to solve energy anxiety. [2] Zn-ion aqueous batteries (ZIB) are an ideal electrochemical charge storage system for constructing fiber batteries, owing to their inherent safety, efficient Zn-ion transport dynamics, low cost (≈$ 65 kW −1 h vs ≈$ 300 kW −1 h for Li-ion battery), facile fabrication, and excellent volumetric capacity (5855 vs 2061 mAh cm −3 for Li) of the Zn metal anode. [3] These features have stimulated emerging research interests in developing Zn-ion fiber batteries. [4] For instance, Zhi et al. fabricated a Zn-ion fiber battery with α-MnO 2 as the cathode and Zn metal decorating two double helix carbon nanotube (CNT) fibers as the anode, in which a ZIB yarn woven into textile was demonstrated. However, in comparison with thin-film counterparts, the limited specific capacity of 302.1 mAh g −1 and volumetric energy density of 53.8 mWh cm −3 still hinder its broad application in providing long-term power for wearable electronics due to the insufficient active materials loading via the dip-coating strategy. [4c] In contrast to planar flexible batteries, fiber electrodes are of vital importance in determining energy storage performance and flexibility of the final fibrous ZIB. [5] Generally, fiber electrode fabrication strategies can be classified into two categories: i) surface coating/in situ growth that deposits active materials onto conductive fiber substrates [6] and ii) wet-spinning via incorporating target materials [7] (e.g., conducting polymers or metal oxides) with carbon-based nanomaterials (e.g., graphene or CNTs). Although surface-coating/in situ growth are feasible approaches to construct fiber electrodes through dip-coating or electrochemical deposition, the thus-fabricated electrodes so far only show limited active material loading and inadequate interfacial adhesion, which tends to create detrimental cracks or even severe abscission after repeated configuration deformation (e.g., bending, twisting, and stretching). These drawbacks significantly constrain the initial specific capacity, mechanical durability and long-term electrochemical stability. [8] Among the prevailing strategies, wet-spinning has been affirmed as a fascinating approach to surmount the aforementioned issues encountered with surface coated fiber electrodes. [9] Wet-spinning is a promising strategy to fabricate fiber electrodes for real commercial fiber battery applications, according to its great compatibility with large-scale fiber production. However, engineering the rheological properties of the electrochemical active materials to accommodate the viscoelasticity or liquid crystalline requirements for continuous wet-spinning remains a daunting challenge. Here, with entropy-driven volume-exclusion effects, the rheological behavior of vanadium pentoxide (V 2 O 5 ) nanowire dispersions is regulated through introducing 2D graphene oxide (GO) flakes in an optim...