Hydrophobic Two-Dimensional Layered Superstructure of a Polyoxometalate Cluster as the Cathode Material for Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries hold promise for sustainable energy storage, yet challenges in finding high-performance cathode materials persist. Polyoxovanadates (POVs) are emerging as potential candidates due to their structural diversity and robust redox activity. Despite their potential, issues like dissolution in electrolytes, structural degradation, and byproduct accumulation persist. This work introduces a POV-based hydrophobic two-dimensional (2D) layered superstructure that addresses these challenges. The hydrophobic nature minimizes POV dissolution, enhancing structural stability and inhibiting phase transitions during cycling. The 2D arrangement ensures a larger surface area and improved electronic conductivity, resulting in faster kinetics and higher specific capacity. The superstructure demonstrates improved cycle life and an increased operating voltage, marking a significant advancement in POV-based cathode materials for aqueous zinc-ion batteries.

Chiral Transfer and Evolution in Cysteine Induced Cobalt Superstructures.

Chiral organic additives have unveiled the extraordinary capacity to form chiral inorganic superstructures, however, complex hierarchical structures have hindered the understanding of chiral transfer and growth mechanisms. This study introduces a simple hydrothermal synthesis method for constructing chiral cobalt superstructures with cysteine, demonstrating specific recognition of chiral molecules and outstanding electrocatalytic activity. The mild preparation conditions allow in situ tracking of chirality evolution in the chiral cobalt superstructure, offering unprecedented insights into the chiral transfer and amplification mechanism. The resulting superstructures exhibit a universal formation process applicable to other metal oxides, extending the understanding of chiral superstructure evolution. This work contributes not only to the fundamental understanding of chirality in self-assembled structures but also provides a versatile method for designing chiral inorganic nanomaterials with remarkable molecular recognition and electrocatalytic capabilities.

Chirality-enhanced 2D conductive polymer for flexible electronics and chiral sensing applications.

Chiral two-dimensional (2D) conductive polymers, encompassing chiral, 2D, flexible, and conductive properties, constitute a novel class of material that remains largely unexplored. The infusion of chirality into 2D conductive polymers taps into the unique characteristics associated with chirality, presenting opportunities to enhance or tailor the electronic, optical, and structural properties of materials for specific technological applications. In this study, we synthesized a chiral 2D PEDOT:PMo11V nanofilm through interfacial polymerization, effectively integrating a chiral monolayer, conductive polymer, and inorganic cluster. The inclusion of inorganic cluster serves to enhance the conductivity of the resulting chiral nanofilm. Furthermore, we demonstrated the chiral nanofilm as a capable electrochemical sensor for detecting drug enantiomers. The inherent flexibility of the chiral nanofilm also lays the groundwork for the development of chiral flexible/wearable devices.

Synergistic Cation-π Interactions and PEDOT-Based Protective Double-Layer for High Performance Zinc Anode.

Ensuring effective and controlled zinc ion transportation is crucial for functionality of the solid electrolyte interphase (SEI) and overall performance in zinc-based battery systems. Herein the first-ever demonstration of incorporate cation-π interactions are provided in the SEI to effectively facilitate uniform zinc ion flux. The artificial SEI design involves the immobilization of 4-amino-p-terphenyl (TPA), a strong amphiphilic cation-π interaction donor, as a monolayer onto a conductive poly(3,4-ethylenedioxythiophene) (PEDOT) matrix, which enable the establishment of a robust network of cation-π interactions. Through a carefully-designed interfacial polymerization process, a high-quality, large-area, robust is achieved, thin polymeric TPA/PEDOT (TP) film for the use of artificial SEI. Consequently, this interphase exhibits exceptional cycling stability with low overpotential and enables high reversibility of Zn plating/stripping. Symmetrical cells with TP/Zn electrodes can be cycled for more than 3200 hours at 1 mA cm-2 and 1 mAh cm-2 . And the asymmetric cells can cycle 3000 cycles stably with a high Coulomb efficiency of 99.78%. Also, under the extreme conditions of lean electrolyte and low N/P ratio, the battery with TP protective layer can still achieve ultra-stable cycle.

Pure Amorphous and Ultrathin Phosphate Layer with Superior Ionic Conduction for Zinc Anode Protection.

Fast and uniform ion transport within the solid electrolyte interphase (SEI) is considered a crucial factor for ensuring the long-term stability of metal electrodes. In this study, we present the fabrication of ultrathin artificial interphases consisting of a zinc phosphate nanofilm with pure amorphous characteristics and a surfactant overlayer. The thickness of the interphases can be precisely controlled within the range of a few tens of nanometers. We explore the impact of artificial SEI structure, including thickness and crystallinity, on its protective capabilities. The pure amorphous phosphate layer with optimized nanoscale thickness is found to provide an abundance of short and isotropic ion migration pathways and a low diffusion energy barrier. These features facilitate rapid and homogeneous Zn2+ transportation, resulting in compact and planar zinc deposition. Meanwhile, the hydrophobic alkyl moieties of the overlayer prevent disassociation of water at the interface. As a result, this nanofilm endures ultralong cycling stability with a low overpotential and enables high Zn plating/stripping reversibility. The Zn||MnO2 full cell shows a stable cycle life for 700 cycles under practical conditions of lean electrolyte, high areal capacity cathode, and limited Zn excess. These findings provide insights into the design and optimization of SEI layers for protection of metal anodes.

Defect-Engineered VS2 Electrocatalysts for Lithium-Sulfur Batteries.

Defective two-dimensional transition metal dichalcogenides can be effective electrocatalysts for Li-S batteries, but the relationship between defect types and battery performance is unclear. In this work, we designed S vacancy-type SV-VS2 and V self-intercalated-type VI-VS2 and measured their catalytic activities in Li-S batteries. Compared with self-intercalating V atoms, S vacancies accelerated Li+ diffusion and SV-VS2 as a Li+ "reservoir" promoted the sulfur conversion kinetics significantly. In addition, the presence of sulfur vacancies promoted the lithiation behavior of SV-VS2 during discharge, leading to an enhancement of the catalytic ability of SV-VS2. However, this lithiation phenomenon weakened the catalytic activity of VI-VS2. Overall, SV-VS2 had better adsorption and catalytic activity. Li-S batteries with SV-VS2-coated separators delivered high rate performance and excellent cycling stability, with a capacity decay rate of 0.043% over 880 cycles at 1.0 C. This work provides an effective strategy for designing efficient Li-S battery electrocatalysts using defect engineering.