An In Situ Electrochemical Amorphization Electrode Enables High-Power High-Cryogenic Capacity Aqueous Zinc-Ion Batteries

Quick-charge technology is of great significance for the development of aqueous zinc-ion batteries. In this study, an unreported in situ electrochemical amorphization mechanism is highlighted to unlock the ultrafast-kinetics electrode. Multiple characterizations, density functional theory calculation, and molecular dynamic simulation are applied to uncover the storage mechanism of electrodes, as well as the evolution of structure, and reaction kinetics after reconstruction. As revealed, the long-range ordered ZnV₂O₄ crystalline can be reconstructed to a short-range ordered Zn_0.44V₂O₄ electrode, which exhibits significantly improved active sites, shortened diffusion path, and enhanced zinc ions capture ability. Notably, by pairing with the modified Zn anode, it can display ultrahigh rate capability (212 mAh g⁻¹ at 50 A g⁻¹) with a maximum power density of 23.2 kW kg⁻¹, as well as good cycle performance (217.2 mAh g⁻¹ after 3000 cycles at 20 A g⁻¹). Unexpectedly, such reconstructed amorphous electrodes can also retain superior storage capability even at cryogenic conditions. A high specific capacity of 251 mAh g⁻¹ can be delivered at −25°C and 1 A g⁻¹, as well as an 84.3% capacity retention after 500 cycles. This brand-new in-situ electrochemical amorphization mechanism is expected to provide new insight into understanding the high-performance aqueous zinc-ion batteries.     

In Situ Inkjet Printing Strategy for Fabricating Perovskite Quantum Dot Patterns

Perovskite quantum dots are emerging as attractive materials for photonic and optoelectronic applications. Patterning is an important step to incorporate them into display, anti‐counterfeiting, and optical chip applications. In this work, an in situ inkjet printing strategy is demonstrated for fabricating perovskite quantum dots patterns by printing perovskite precursor solutions onto a polymeric layer. Importantly, this strategy can achieve bright photoluminescence with a quantum yield up to 80% and shows broad applicability to a variety of perovskites and polymers. Moreover, the as‐fabricated perovskite quantum dots patterns are composed of a microdisks array on the surface of polymeric layer. The size of these microdisks can be varied by adjusting the printing temperature. To demonstrate the potential use in display and advanced anti‐counterfeiting applications, color pixel patterns and 2D code pattern are fabricated by varying the precursor solutions. The combination of superior photoluminescence properties, simple process, and low cost makes the in situ inkjet printing strategy very promising for patterning perovskite quantum dots toward photonic integrations.     

Horizontally-Oriented Growth of Organic Crystalline Nanowires on Polymer Films for In-Situ Flexible Photodetectors with Vis-NIR Response and High Bending Stability

Various epitaxial mechanisms have been proposed to control the growth orientation of vapor-deposited nanowires, yet the required lattice matching between target nanowires and supporting substrates limits their applicability. In this work, a versatile hot stamping protocol for fabricating parallel hydrophobic nanogrooves on flexible polymer films (e.g., polyimide (PI), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS)) is proposed. More interestingly, various organic small molecules, including several metal phthalocyanines (MPc, M = Cu, Zn, Fe, Ni, Co), 9,10-bis(phenylethynyl)anthracene (BPEA), 9,10-diphenylanthracene (DPA), and tris-(8-hydroxyquinoline)aluminium (Alq₃), are directly assembled into horizontally-oriented nanowires along the hot-stamped nanogrooves on a flexible PI film, thereby breaking the lattice-matching limitation for oriented nanowire growth. These submillimeter-long horizontally oriented nanowires can be integrated into flexible photodetectors directly on their growth film, eliminating the need for laborious post-growth transfer and alignment steps and the associated structural damage and contamination. Consequently, the in situ integrated flexible photodetector made of aligned CuPc nanowires maintains a stable and fast photoresponse to a spectrum in the region of 405-980 nm even when the detector is bent to a radius of curvature of 2.5 mm and 1000 times. This work will open new opportunities to develop in situ integrated flexible devices based on organic crystalline nanowires for practical applications.     

Revealing the Dynamics of Hybrid Metal Halide Perovskite Formation via Multimodal In Situ Probes

The exploration of the synthetic space of halide perovskites hinges on an enormous number of parameters requiring time‐consuming experimentation to decouple and optimize. Here, the formation of the prototype material CH₃NH₃PbI₃ (MAPbI₃) is investigated at different time and length scales using multimodal in situ measurements to monitor the evolution of crystalline phases, morphology, and photoluminescence as a function of the lead precursors. Kinetically fast formation of crystalline precursor phases already during the spin‐coat deposition is observed using lead iodide (PbI₂) or lead chloride (PbCl₂) routes. These precursor phases most likely template final MAPbI₃ film morphology. In particular, the emergence of the “needle‐like” structure is shown to appear before film annealing. In situ photoluminescence measurements suggest nanoscale nucleation followed by rapid nuclei densification and growth. Using this multimodal in situ approach, different formation pathways can be identified either via precursor phases in the PbI₂ and PbCl₂ routes or direct perovskite formation from molecular building blocks as observed in the lead acetate (PbAc₂) route. Correlation of in situ results with photovoltaic device performance demonstrates the power of in situ multimodal techniques, paves the way to a fast screening of synthetic parameters, and ultimately leads to controlled synthetic procedures that yield high‐efficiency devices.     

In Situ Self-Assembly of Ordered Organic/Inorganic Dual-Layered Interphase for Achieving Long-Life Dendrite-Free Li Metal Anodes in LiFSI-Based Electrolyte

Metallic lithium electrode with high capacity of 3860 mA h g⁻¹ is the most promising candidate for rechargeable batteries. However, some inherent problems such as dendrite growth, uneven solid electrolyte interphase (SEI), and high manufacturing risk restraint its practical application. Herein, distinct from the conventional mosaic structure, a facile fabrication of in situ self-assembled organic/inorganic hybrid SEI with ordered dual-layer structure on the lithium surface to suppress dendrite formation is proposed. With the aid of moderate active fluoric-containing ionic liquid, the as-formed lithium fluoride and robust ordered organic moieties are in situ self-assembled on the metallic lithium surface. The evolution process of the dual-layered structure is revealed by X-ray spectroscopy, in situ sum frequency generation spectroscopy, and atomic force microscopy. The formed “double protection” ordered hybrid interphase layer also exhibits the surprising ability against the corrosion of carbonate electrolyte or dry air. As a consequence, the pretreated metallic lithium electrode represents excellent stripping/plating reversibility of ≈99% and a long lifespan up to 1200 h without formation of dendrite, and remains high performance at a current density of 10 mA cm⁻², which is much higher than most reports, showing the facilitating promising to the future utilization.     

In Situ Crosslinkable Gelatin Hydrogels for Vasculogenic Induction and Delivery of Mesenchymal Stem Cells

Clinical trials utilizing mesenchymal stem cells (MSCs) for severe vascular diseases have highlighted the need to effectively engraft cells and promote pro‐angiogenic activity. A functional material accomplishing these two goals is an ideal solution as spatiotemporal and batch‐to‐batch variability in classical therapeutic delivery can be minimized, and tissue regeneration would begin rapidly at the implantation site. Gelatin may serve as a promising biomaterial due to its excellent biocompatibility, biodegradability, and non‐immuno/antigenicity. However, the dissolution of gelatin at body temperature and quick enzymatic degradation in vivo have limited its use thus far. To overcome these challenges, an injectable, in situ crosslinkable gelatin was developed by conjugating enzymatically crosslinkable hydroxyphenyl propionic acid (GHPA). When MSCs are cultured in 3D in vitro or injected in vivo in GHPA, spontaneous endothelial differentiation occurs, as evidenced by marked increases in endothlelial cell marker expressions (Flk1, Tie2, ANGPT1, vWF) in addition to forming an extensive perfusable vascular network after 2‐week subcutaneous implantation. Additionally, favorable host macrophage response is achieved with GHPA as shown by decreased iNOS and increased MRC1 expression. These results indicate GHPA as a promising soluble factor‐free cell delivery template which induces endothelial differentiation of MSCs with robust neovasculature formation and favorable host response.     

Microgel Assembly Powder Improves Acute Hemostasis,Antibacterial, and Wound Healing via In Situ Co-Assembly of Erythrocyte and Microgel

Rapid and effective hemostasis on irregular-shaped non-compressible bleeding wounds is still one of the key challenges in clinical practice. Herein, a novel multi-functional microgel assembly powder (MAP) composed of oxidized dextran/methacrylate gelatin (ODex/GelMA) microgel powder and long-chain alkyl quaternized chitosan (LQCS) crosslinker powder is reported for acute hemostasis, antibacterial, and wound healing. When MAP is applied onto bleeding wounds, porous ODex/GelMA microgel powder immediately absorbs massive liquid in blood whilst LQCS induces in situ co-assembly of erythrocytes and microgels. In other words, MAP combines the merits of hemostatic powders and hemostatic hydrogels, that is, the excellent hemostasis performance of MAP is originated from not only the high fluid uptake ratio/rate that causes the aggregation of coagulation factors and erythrocytes, but also the formation of erythrocytes-involved hydrogel-like microgel assembly that dramatically improves the mechanical strength, tissue adhesion and wound sealing performance in blood compared with those in PBS. In addition, MAP also exhibits excellent antibacterial ability, and promotes the wound healing in bacterial-infected full-thickness skin wounds. The fantastic features of MAP including low cost, easy synthesis and usage, excellent hemostasis on irregular-shaped, non-compressible bleeding wounds, outstanding antibacterial and wound healing, good cytocompatibility, make it a promising hemostatic material and wound dressing.     

In Situ Fabrication of Three‐Dimensional Graphene Films on Gold Substrates with Controllable Pore Structures for High‐Performance Electrochemical Sensing

In this work, novel three‐dimensional graphene films (3D GFs) with controllable pore structures are directly fabricated on gold substrates through the hydrothermal reduction. An interfacial technique of the self‐assembled monolayer is successfully introduced to address the binding issue between the graphene film and substrate. Adscititious silica spheres, serving as new connection centers, effectively regulate the dimensions of framework in graphene films, and secondary pore structures are produced once removing the spheres. Based on hierarchically porous 3D GFs with large surface area, excellent binding strength, high conductivity, and distinct interfacial micro‐environments, selected examples of electrochemical aptasensors are constructed for the assay of adenosine triphosphate (ATP) and thrombin (Tob) respectively. Sensitive ATP and Tob aptasensors, with high selectivity, excellent stability, and promising potential in real serum sample analysis, are established on 3D GFs with different structures. The results demonstrate that the surface area, as well as interfacial micro‐environments, plays a critical role in the molecular recognition. The developed reliable and scalable protocol is envisaged to become a general path for in situ fabrication of more graphene films and the as‐synthesized 3D GFs would open up a wide horizon for potential applications in electronic and energy‐related systems.     

In Situ Generated Gas Bubble‐Directed Self‐Assembly: Synthesis,and Peculiar Magnetic and Electrochemical Properties of Vertically Aligned Arrays of High‐Density Co3O4 Nanotubes

A novel and versatile gas bubble induced self‐assembly technique is developed for the one‐step fabrication of vertically aligned polycrystalline Co₃O₄ nanotube arrays (NTAs) by the rapid thermal decomposition of Co(NO₃)₂·6H₂O on a flat substrate. In this protocol, the in situ generation and release of gas bubbles, which can be regulated by elaborately adjusting the kinetic factors such as reaction time, decomposition temperature and pressure as well as the content of the chemically adsorbed water, play a vital role in the formation of the Co₃O₄ NTAs. Due to the shape anisotropy, ordered hierarchically porous structure and high surface area, the as‐obtained Co₃O₄ NTAs show unique magnetic properties of a low Néel temperature and a large exchange bias field, as well as an initial discharge capacity up to 1293 mAh·g^?1 at 35 mA·g^?1 and the retention of a charge capacity as high as 895.4 mAh·g^?1 after 10 cycles. This endows them with important potential use in magnetic shielding, magnetic recording media, and lithium ion batteries, etc. Due to the simplicity of the self‐assembly method, this process is applicable to the large‐scale production of the Co₃O₄ NTAs, and may be extended to other materials.     

A New rGO‐Overcoated Sb2Se3 Nanorods Anode for Na+ Battery: In Situ X‐Ray Diffraction Study on a Live Sodiation/Desodiation Process

Sodium ion batteries (SIBs) are a promising alternative to lithium ion batteries for a broader range of energy storage applications in the future. However, the development of high‐performance anode materials is a bottleneck of SIBs advancement. In this work, Sb₂Se₃ nanorods uniformly wrapped by reduced graphene oxide (rGO) as a promising anode material for SIBs are reported. The results show that such Sb₂Se₃/rGO hybrid anode yields a high reversible mass‐specific energy capacity of 682, 448, and 386 mAh g^?1 at a rate of 0.1, 1.0, and 2.0 A g^?1, respectively, and sustains at least 500 stable cycles at a rate of 1.0 A g^?1 with an average mass‐specific energy capacity of 417 mAh g^?1 and capacity retention of 90.2%. In situ X‐ray diffraction study on a live SIB cell reveals that the observed high performance is a result of the combined Na⁺ intercalation, conversion reaction between Na⁺ and Se, and alloying reaction between Na⁺ and Sb. The presence of rGO also plays a key role in achieving high rate capacity and cycle stability by providing good electrical conductivity, tolerant accommodation to volume change, and strong electron interactions to the base Sb₂Se₃ anode.     

Probing the Self‐Boosting Catalysis of LiCoO2 in Li–O2 Battery with Multiple In Situ/Operando Techniques

Designing high‐activity catalysts and revealing the in‐depth structure–property relationship is particularly important for Li–O₂ batteries. Herein, the self‐boosting catalysis of LiCoO₂ as an electrocatalyst for Li–O₂ batteries and the investigation of its self‐adjustment mechanism using in situ X‐ray absorption spectroscopy and other operando characterization techniques is reported. The intercalation/extraction of Li⁺ in LiCoO₂ not only induces the change in Co valence and modulates the electronic/crystal structure but also tunes the surface disorder degree, lattice strain, and local symmetry, which all affect the catalysis activity. In a discharge, highly ordered LiCoO₂ acts as a catalyst to boost oxygen reduction reaction. During charging, the initial extraction of Li⁺ from LiCoO₂ induces Li/oxygen vacancy and Co⁴⁺, which deforms CoO₆ octahedron as well as lowers the symmetry, and accordingly promotes oxygen evolution reaction. This article offers insights into tuning the activity of catalysts for Li–O₂ batteries with the intercalation/extraction of alkali metal ions in traditional cathodes.     

A General Metal‐Organic Framework (MOF)‐Derived Selenidation Strategy for In Situ Carbon‐Encapsulated Metal Selenides as High‐Rate Anodes for Na‐Ion Batteries

On account of increasing demand for energy storage devices, sodium‐ion batteries (SIBs) with abundant reserve, low cost, and similar electrochemical properties have the potential to partly replace the commercial lithium‐ion batteries. In this study, a facile metal‐organic framework (MOF)‐derived selenidation strategy to synthesize in situ carbon‐encapsulated selenides as superior anode for SIBs is rationally designed. These selenides with particular micro‐ and nanostructured features deliver ultrastable cycling performance at high charge–discharge rate and demonstrate ultraexcellent rate capability. For example, the uniform peapod‐like Fe₇Se₈@C nanorods represent a high specific capacity of 218 mAh g^?1 after 500 cycles at 3 A g^?1 and the porous NiSe@C spheres display a high specific capacity of 160 mAh g^?1 after 2000 cycles at 3 A g^?1. The current simple MOF‐derived method could be a promising strategy for boosting the development of new functional inorganic materials for energy storage, catalysis, and sensors.