Synergistic Modulation of Mass Transfer and Parasitic Reactions of Zn Metal Anode via Bioinspired Artificial Protection Layer.

Rechargeable aqueous zinc-ion batteries are regarded as promising energy storage devices due to their attractive economic benefits and extraordinary electrochemical performance. However, the sluggish Zn2+ mass transfer behavior and water-induced parasitic reactions that occurred on the anode-electrode interface inevitably restrain their applications. Herein, inspired by the selective permeability and superior stability of plasma membrane, a thin UiO-66 metal-organic framework layer with smart aperture size is ex-situ decorated onto the Zn anode. Experimental characterizations in conjunction with theoretical calculations demonstrate that this bio-inspired layer promotes the de-solvation process of hydrated Zn2+ and reduces the effective contact between the anode and H2 O molecules, thereby boosting Zn2+ deposition kinetics and restraining interfacial parasitic reactions. Hence, the Zn||Zn cells could sustain a long lifespan of 1680 h and the Zn||Cu cells yielded a stable coulombic efficiency of over 99.3% throughout 600 cycles under the assistance of the bio-inspired layer. Moreover, pairing with δ-MnO2 cathode, the full cells also demonstrate prominent cycling stability and rate performance. From the bio-inspired design philosophy, this work provides a novel insight into the development of aqueous batteries.

A Perspective of Bioinspired Interfaces Applied in Renewable Energy Storage and Conversion Devices.

The natural world renders a large number of opportunities to design intriguing structures and fascinating functions for innovations of advanced surfaces and interfaces. Currently, bioinspired interfaces have attracted much attention in practical applications of renewable energy storage and conversion devices including rechargeable batteries, fuel cells, dye-sensitized solar cells, and supercapacitors. By mimicking miscellaneous natural creatures, many novel bioinspired interfaces with various components, structures, morphology, and configurations are exerted on the devices' electrodes, electrolytes, additives, separators, and catalyst matrixes, resorting to their wonderful mechanical, optical, electrical, physical, chemical, and electrochemical features compared with the corresponding traditional modes. In this Perspective, the principles of designing bioinspired interfaces are discussed with respect to biomimetic chemical components, physical morphologies, biochemical reactions, and macrobiomimetic assembly configurations. A brief summary, subsequently, is mainly focused on the recent progress on bioinspired interfaces applied in key materials for rechargeable batteries. Ultimately, a critical comment is projected on significant opportunities and challenges existing in the future development course of bioinspired interfaces. It is expected that this Perspective is able to provide a profound perception into some underlying artificial intelligent energy storage and conversion device design as a promising candidate to resolve the global energy crisis and environmental pollution.

Modulating Surface Electron Density of Heterointerface with Bio-Inspired Light-Trapping Nano-Structure to Boost Kinetics of Overall Water Splitting.

Herein, inspired by natural sunflower heads' properties increasing the temperature of dish-shaped flowers by tracking the sun, a novel hybrid heterostructure (MoS2 /Ni3 S2 @CA, CA means carbon nanowire arrays) with the sunflower-like structure to boost the kinetics of water splitting is proposed. Density functional theory (DFT) reveals that it can modulate the active electronic states of NiMo atoms around the Fermi-level through the charge transfer between the metallic atoms of Ni3 S2 and MoMo bonds of MoS2 to boost overall water splitting. Most importantly, the finite difference time domain (FDTD) could find that its unique bio-inspired micro-nano light-trapping structure has high solar photothermal conversion efficiency. With the assistance of the photothermal field, the kinetics of water-splitting is improved, affording low overpotentials of 96 and 229 mV at 10 mA cm-2 for HER and OER, respectively. Moreover, the Sun-MoS2 /Ni3 S2 @CA enables the overall alkaline water splitting at a low cell voltage of 1.48 and 1.64 V to achieve 10 and 100 mA cm-2 with outstanding catalytic durability. This study may open up a new route for rationally constructing bionic sunflower micro-nano light-trapping structure to maximize their photothermal conversion and electrochemical performances, and accelerate the development of nonprecious electrocatalysts for overall water splitting.

Electrolyte Regulation of Bio-Inspired Zincophilic Additive toward High-Performance Dendrite-Free Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries hold attractive potential for large-scale energy storage devices owing to their prominent electrochemical performance and high security. Nevertheless, the applications of aqueous electrolytes have generated various challenges, including uncontrolled dendrite growth and parasitic reactions, thereby deteriorating the Zn anode's stability. Herein, inspired by the superior affinity between Zn2+ and amino acid chains in the zinc finger protein, a cost-effective and green glycine additive is incorporated into aqueous electrolytes to stabilize the Zn anode. As confirmed by experimental characterizations and theoretical calculations, the glycine additives can not only reorganize the solvation sheaths of hydrated Zn2+ via partial substitution of coordinated H2 O but also preferentially adsorb onto the Zn anode, thereby significantly restraining dendrite growth and interfacial side reactions. Accordingly, the Zn anode could realize a long lifespan of over 2000 h and enhanced reversibility (98.8%) in the glycine-containing electrolyte. Furthermore, the assembled Zn||α-MnO2 full cells with glycine-modified electrolyte also delivers substantial capacity retention (82.3% after 1000 cycles at 2 A g-1 ), showing promising application prospects. This innovative bio-inspired design concept would inject new vitality into the development of aqueous electrolytes.

Electrolyte Modulation of Biological Chelation Additives toward a Dendrite-Free Zn Metal Anode.

Aqueous zinc-ion batteries are considered promising energy storage devices due to their superior electrochemical performance. Nevertheless, the uncontrolled dendrites and parasitic side reactions adversely affect the stability and durability of the Zn anode. To cope with these issues, inspired by the chelation behavior between metal ions and amino acids in the biological system, glutamic acid and aspartic acid are selected as electrolyte additives to stabilize the Zn anode. Experimental characterizations in conjunction with theoretical calculation results indicate that these additives can simultaneously modify the solvation structure of hydrated Zn2+ and preferentially adsorb onto the Zn anode, thereby restricting the occurrence of interfacial side reactions and enhancing the performance of the Zn anode. Benefiting from these synergistic effects, the as-assembled Zn-based batteries containing additive electrolytes achieved admirable electrochemical performance. From the viewpoint of electrolyte regulation, this work provides a bright direction toward the development of aqueous batteries.

Subnanocyclic Molecule of 15-Crown-5 Inhibiting Interfacial Water Decomposition and Stabilizing Zinc Anodes via Regulation of Zn2+ Solvation Shell.

Aqueous zinc ion batteries exhibit a promising application prospect for next-generation energy storage devices. However, the decomposition of active H2O molecules on the Zn anode induces drastic dendrite formation, thereby impairing the performance for entire devices. To solve this challenge, we introduce subnanocyclic molecules of 15-Crown-5 as an additive into ZnSO4 electrolyte to stabilize the Zn anode. Owing to the binding property of crown ethers with alkali metal ions and the size-fit rule, the 15-Crown-5 additives enable effective regulation of the solvation structure of hydrated Zn2+ and reduce the efficient contact between Zn anode and active H2O, which are validated by the experimental analysis and theoretical calculations. Under the assistance of the 15-Crown-5 additive, the as-assembled Zn-based batteries deliver superior performance compared with ZnSO4 and 18-Crown-6contaning ZnSO4 electrolytes. This work shows a bright direction toward progress in aqueous batteries.