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The intelligent construction of non-noble metal materials that exhibit reversible oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with bifunctional electrocatalytic performance is greatly coveted in the realm of zinc-air batteries (ZABs). Herein, a crafted structure-amorphous MnO 2 lamellae encapsulated covalent triazine polymer-derived N, S, P co-doped carbon sphere (A-MnO 2 /NSPC) is designed using a self-doped pyrolysis coupled with an in situ encapsulation strategy. The customized A-MnO 2 /NSPC-2 demonstrates a superior bifunctional electrocatalytic performance, confirmed by a small ΔE index of 0.64 V for ORR/OER. Experimental investigations, along with density functional theory calculations validate that predesigned amorphous MnO 2 surface defects and abundant heteroatom catalytic active sites collectively enhance the oxygen electrocatalytic performance. Impressively, the A-MnO 2 /NSPC-based rechargeable liquid ZABs show a large open-circuit potential of 1.54 V, an ultrahigh peak power density of 181 mW cm -2 , an enormous capacity of 816 mAh g -1 , and a remarkable stability for more than 1720 discharging/charging cycles. Additionally, the assembled flexible all-solid-state ZABs also demonstrate outstanding cycle stability, surpassing 140 discharging/charging cycles. Therefore, this highly operable synthetic strategy offers substantial understanding in the development of magnificent bifunctional electrocatalysts for various sustainable energy conversions and beyond., (© 2024 Wiley‐VCH GmbH.)

The quasi-solid electrolytes (QSEs) attract extensive attention due to their improved ion transport properties and high stability, which is synergistically based on tunable functional groups and confined solvent molecules among the polymetric networks. However, the trade-off effect between the polymer content and ionic conductivity exists in QSEs, limiting their rate performance. In this work, the epitaxial polymerization strategy is used to build the gradient hydrogel networks (GHNs) covalently fixed on zinc anode. Then, it is revealed that the asymmetric distribution of negative charges benefits GHNs with fast and selective ionic transport properties, realizing a higher Zn 2+ transference number of 0.65 than that (0.52) for homogeneous hydrogel networks (HHNs) with the same polymer content. Meanwhile, the high-density networks formed at Zn/GHNs interface can efficiently immobilize free water molecules and homogenize the Zn 2+ flux, greatly inhibiting the water-involved parasitic reactions and dendrite growth. Thus, the GHNs enable dendrite-free stripping/plating over 1000 h at 8 mA cm -2 and 1 mAh cm -2 in a Zn||Zn symmetric cell, as well as the evidently prolonged cycles in various full cells. This work will shed light on asymmetric engineering of ion transport channels in advanced quasi-solid battery systems to achieve high energy and safety., (© 2023 Wiley-VCH GmbH.)

Ion-selective membranes act as the core components in osmotic energy harvesting, but remain with deficiencies such as low ion selectivity and a tendency to swell. 2D nanofluidic membranes as competitive candidates are still subjected to limited mass transport brought by insufficient wetting and poor stability in water. Here, an ionic-liquid-infused graphene oxide (GO@IL) membrane with ultrafast ion transport ability is reported, and how the confined ionic liquid mediates selective cation diffusion is revealed. The infusion of ionic liquids endows the 2D membrane with excellent mechanical strength, anti-swelling properties, and good stability in aqueous electrolytes. Importantly, immiscible ionic liquids also provide a medium, allowing partial dehydration for ultrafast ion transport. Through molecular dynamics simulation and finite element modeling, that GO nanosheets induce ionic liquids to rearrange, bringing in additional space charges, which can be coupled with GO synergistically, is proved. By mixing 0.5/0.01 m NaCl solution, the power density can achieve a record value of ≈6.7 W m -2 , outperforming state-of-art GO-based membranes. This work opens up a new route for boosting nanofluidic energy conversion because of the diversity of the ILs and 2D materials., (© 2023 Wiley-VCH GmbH.)

Charge-governed ion transport is the vital property of nanofluidic channels for salinity-gradient energy harvesting and other electrochemical energy conversion technologies. 2D nanofluidic channels constructed by nanosheets exhibit great superiority in ion selectivity, but a high ion transport rate remains challenging due to the insufficiency of intrinsic surface charge density in nanoconfinement. Herein, extrinsic surface charge into nanofluidic channels composed of surfactant-assisted sulfonated covalent organic nanosheets (SCONs), which enable tunable ion transport behaviors, is demonstrated. The polar moiety of surfactant is embedded in SCONs to adjust in-plane surface charges, and the aggregation of nonpolar moiety results in the sol-to-gel transformation of SCON solution for membrane fabrication. The combination endows SCON/surfactant membranes with considerable water-resistance, and the designable extrinsic charges promise fast ion transport and high ion selectivity. Additionally, the SCON/surfactant membrane, serving as a power generator, exhibits huge potential in harvesting salinity-gradient energy where corresponding output power density can reach up to 9.08 W m -2 under a 50-fold salinity gradient (0.5 m NaCl|0.01 m NaCl). The approach to extrinsic surface charge provides new and promising insight into regulating ion transport behaviors., (© 2022 Wiley-VCH GmbH.)

Charge-governed ion transport is crucial to numerous industries, and the advanced membrane is the essential component. In nature, the efficient and selective ion transport is mainly governed by the charged ion channels located in cell membrane, indicating the architecture with functional differentiation. Inspired by this architecture, a membrane by ionic crosslinking sulfonated poly(arylene ether ketone) and imidazolium-functionalized poly(arylene ether sulfone) is designed and fabricated to make full use of the charges. This ionic crosslinking is designed to realize nanophase separation to aggregate the ion pathways in the membrane, which results in excellent ion selectivity and high ion conductivity. With the excellent ion transport behavior, ionic crosslinking membrane shows great potential in osmotic energy conversion, which maximum power density can be up to 16.72 W m -2 . This design of ionic crosslinking-induced nanophase separation offers a roadmap for ion transport promotion., (© 2021 Wiley-VCH GmbH.)

A novel CO 2 -driven ionic gate, mimicking the function of olfactory sensory neurons of mosquitoes, is successfully developed by functionalizing the walls of the nanochannels using 1-(4-amino-phenyl)-2,2,2-trifluoro-ethanone. This artificial nanochannel can switch between the ON-state and OFF-state in the presence and absence of CO 2 , with an ultrahigh gating ratio of up to 1250, and has potential applications in CO 2 -related sensing, gating, and nanofluidic systems., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Asymmetric multifunctional heterogeneous membranes are demonstrated by combing a block copolymer polystyrene-block-poly(N,N-dimethylaminoethylmethacrylate) membrane with a track-etched porous poly(ethylene terephthalate) membrane. This hybrid membrane is capable of integrating pH- and temperature-cooperative high-performance ionic rectification, highly efficient cation gating, and excellent stability and controllability, which allows broad application in biosensing, energy conversion, and filtration., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The enhanced stability and controllability of an ionic diode system based on funnel-shaped nanochannels with a much longer critical region is reported. The polarity of ion transport switching from anion/cation-selective to ambipolar can be controlled by tuning the length and charge of the critical region. This nanofluidic structure anticipates potential applications in single-molecule biosensing, water resource monitoring, and healthcare., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A novel biomimetic voltage-gated chloride nanochannel is described. This artificial nanochannel can realize reversible switching between the "on" and "off" states upon addition and removal of Cl(-) and can realize the selective and directional transport of Cl(-) driven by voltage. Moreover, it also has high sensitivity, good selectivity, responsive switchability, and good stability., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Asymmetric composite membranes with rectifying properties are developed by grafting pH-stimulus-responsive materials onto the top layer of the composite structure, which is prepared by two novel block copolymers using a phase-separation technique. This engineered asymmetric composite membrane shows potential applications in sensors, filtration, and nanofluidic devices., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A bioinspired multifunctional heterogeneous membrane composed of a block copolymer (PS-b-P4VP) membrane and a porous anodic alumina membrane is fabricated. The ionic rectification is so strong that the maximum ratio is ≈489, and the chemical actuation of the anion or cation gate from the "OFF" to the "ON" state promotes a 98.5% increase in the channel conductance., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)