RESUMEN
The inner Helmholtz plane and thus derived solid-electrolyte interphase (SEI) are crucial interfacial structure to determine the electrochemical stability of Zn-ion battery (ZIB). In this work, we demonstrate that introducing ß-cyclodextrins (CD) as anion-receptors into Zn(OTf)2 aqueous electrolyte could significantly optimize the Zn anode SEI structure for achieving stable ZIB. Specifically, ß-CD with macrocyclic structure holds appropriate cavity size and charge distribution to encase OTf- anions at the Zn metal surface to form ß-CD@OTf- dominated inner Helmholtz structure. Meanwhile, the electrochemically triggered ß-CD@OTf- decomposition could in situ convert to the organic-inorganic hybrid SEI (ZnF2/ZnCO3/ZnSâ(C-O-C/*CF/*CF3)), which could efficiently hinder the Zn dendrite growth with maintain the proper SEI mechanical strength stability to guarantee the long-term stability. The thus-derived Zn | |Zn pouch cell (21 cm2 size) with ß-CD-containing electrolyte exhibits a cumulative capacity of 6450 mAh-2 cm-2 at conditions of 10 mAh cm-2 high areal capacity. This work gives insights for reaching stable ZIB via electrolyte additive triggered SEI structure regulation.
RESUMEN
Alkenylboronates are highly versatile building blocks and valuable reagents in the synthesis of complex molecules. Compared with that of monosubstituted alkenylboronates, the synthesis of multisubstituted alkenylboronates is challenging. The copper-catalyzed carboboration of alkynes is an operationally simple and straightforward method for synthesizing bis/trisubstituted alkenylboronates. In this work, a series of copper-metallized N-Heterocyclic Carbene (NHC) ligand porous polymer catalysts are designed and synthesized in accordance with the mechanism of carboboration. By using CuCl@POL-NHC-Ph as the optimal nanocatalyst, this study realizes the ß-regio- and stereoselective (syn-addition) 1,2-carboboration of alkynes (regioselectivity up to >99:1) with satisfactory yields and a wide range of substrates. This work not only overcomes the selectivity of carboboration but also provides a new strategy for the design of nanocatalysts and their application in organic synthesis.
RESUMEN
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 H2 O and random Zn deposition inside active IHP. Here, we report a universal high donor number (DN) additive pyridine (Py) with only 1â vol. % addition (Py-to-H2 O 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 H2 O molecules from IHP effectively, which is in favor of preventing H2 O 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 500â 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.
RESUMEN
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 5600â h at 1.0â mA cm-2 /1.0â mAh cm-2 .
RESUMEN
2D conducting polymer thin film recently has garnered numerous interests as a means of combining the molecular aggregate ordering and promoting in-plane charge transport for large-scale/flexible organic electronics. However, it remains far from satisfactory for conducting polymer chains to achieve desirable surface topography and crystallinity due to lack of control over the precursor-involved interfacial assembly. Herein, wafer-size polyaniline (PANI) and tetra-aniline thin films are developed via a controlled interfacial synthesis with customized surface morphology and crystallinity through two typical aniline precursors selective polymerization. Two crucial competing assembly mechanisms, a) direct interfacial polymerization, b) solution polymerization and subsequent interfacial assembly, are investigated to play a vital role in determining elemental chain length and aggregate architecture. The optimal PANI thin film manifests ultraflat surface topography and unambiguous crystalline domains, which also enabling fascinating ammonia sensing capability with 31.4% ppm-1 sensitivity, fast response time (88 s) with astonishing selectivity, repeatability, and recovery capability. The thus-demonstrated strategy with wafer-scale processing potential and flexible microdevice offers a promising route for large-scale manufacturing thin-film organic electronics.
Asunto(s)
Compuestos de Anilina , Polímeros , Polimerizacion , Compuestos de Anilina/químicaRESUMEN
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 (V2 O5 ) nanowire dispersions is regulated through introducing 2D graphene oxide (GO) flakes in an optimal ratio. By optimizing the viscoelasticity and liquid-crystalline behavior of the spinning dope, the wet-spun hybrid fibers display controlled hierarchical orientation. The wet-spun V2 O5 /rGO hybrid fiber with the optimal 10:1 mass fraction (V2 O5 /rGO10:1 ) exhibits a highly oriented nanoblock arrangement, enabling efficient Zn-ion migration and an excellent Zn-ion storage capacity of 486.03 mAh g-1 at 0.1 A g-1 . A half-meter long quasi-solid-state fiber Zn-ion battery is assembled with a polyacrylamide gel electrolyte and biocompatible Ecoflex encapsulation. The thus-derived fiber Zn-ion battery is integrated into a wearable self-powered system, incorporating a highly efficient GaAs solar cell, which delivers a record-high overall efficiency (9.80%) for flexible solar charging systems.
RESUMEN
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.