Aggregation‐induced emission (AIE) is an attractive phenomenon in which materials display strong luminescence in the aggregated solid states rather than in the conventional dissolved molecular ...states. However, highly luminescent inks based on AIE are hard to be obtained because of the difficulty in finely controlling the crystallinity of AIE materials at nanoscale. Herein, we report the preparation of highly luminescent inks via oil‐in‐water microemulsion induced aggregation of Cu–I hybrid clusters based on the highly soluble copper iodide‐tris(3‐methylphenyl)phosphine (Cu4I4(P‐(m‐Tol)3)4) hybrid. Furthermore, we can synthesize a series of AIE inks with different light‐emission colors to cover the whole visible spectrum range via a facile ligand exchange processes. The assemblies of Cu–I hybrid clusters with AIE characteristics will pave the way to fabricate low‐cost highly luminescent inks.
Ink‐lined to glow: Highly luminescent inks based on AIE Cu–I hybrids clusters are prepared by the self‐assembly of Cu–I hybrid cluster aggregates in microemulsion droplets. A subsequent ligand exchange step expands the color pallet of the as‐fabricated inks.
Although biomimetic designs are expected to play a key role in exploring future structural materials, facile fabrication of bulk biomimetic materials under ambient conditions remains a major ...challenge. Here, we describe a mesoscale "assembly-and-mineralization" approach inspired by the natural process in mollusks to fabricate bulk synthetic nacre that highly resembles both the chemical composition and the hierarchical structure of natural nacre. The millimeter-thick synthetic nacre consists of alternating organic layers and aragonite platelet layers (91 weight percent) and exhibits good ultimate strength and fracture toughness. This predesigned matrix-directed mineralization method represents a rational strategy for the preparation of robust composite materials with hierarchically ordered structures, where various constituents are adaptable, including brittle and heat-labile materials.
Electrolyte engineering via fluorinated additives is promising to improve cycling stability and safety of high‐energy Li‐metal batteries. Here, an electrolyte is reported in a porous lithium fluoride ...(LiF) strategy to enable efficient carbonate electrolyte engineering for stable and safe Li‐metal batteries. Unlike traditionally engineered electrolytes, the prepared electrolyte in the porous LiF nanobox exhibits nonflammability and high electrochemical performance owing to strong interactions between the electrolyte solvent molecules and numerous exposed active LiF (111) crystal planes. Via cryogenic transmission electron microscopy and X‐ray photoelectron spectroscopy depth analysis, it is revealed that the electrolyte in active porous LiF nanobox involves the formation of a high‐fluorine‐content (>30%) solid electrolyte interphase layer, which enables very stable Li‐metal anode cycling over one thousand cycles under high current density (4 mA cm−2). More importantly, employing the porous LiF nanobox engineered electrolyte, a Li || LiNi0.8Co0.1Mn0.1O2 pouch cell is achieved with a specific energy of 380 Wh kg−1 for stable cycling over 80 cycles, representing the excellent performance of the Li‐metal pouch cell using practical carbonate electrolyte. This study provides a new electrolyte engineering strategy for stable and safe Li‐metal batteries.
Electrolyte engineering via fluorinated additives is promising to improve the cycling stability and safety of high‐energy Li‐metal batteries. The electrolyte in an active porous LiF nanobox involves the formation of a high‐fluorine‐content (>30%) solid electrolyte interphase layer to achieve a ≈3.5 Ah Li || LiNi0.8Co0.1Mn0.1O2 pouch cell with a specific energy of 380 Wh kg−1 under a practical carbonate electrolyte.
Fabricating a robust interfacial layer on the lithium metal anode to isolate it from liquid electrolyte is vital to restrain the rapid degradation of a lithium metal battery. Here, we report that the ...solution-processed metal chloride perovskite thin film can be coated onto the lithium metal surface as a robust interfacial layer to shield the lithium metal from liquid electrolyte. Via phase analysis and density functional theory calculations, we demonstrate that the perovskite layer can allow fast lithium ion shuttle under a low energy barrier of 0.45 eV without the collapse of framework. Such perovskite modification can realize stable cycling of LiCoO
|Li cells with an areal capacity of 2.8 mAh cm
using thin lithium metal foil (50 μm) and limited electrolyte (20 μl mAh
) for over 100 cycles at 0.5 C. The metal chloride perovskite protection strategy could open a promising avenue for advanced lithium metal batteries.
Various methods have been exploited to replicate nacre features into artificial structural materials with impressive structural and mechanical similarity. However, it is still very challenging to ...produce nacre-mimetics in three-dimensional bulk form, especially for further scale-up. Herein, we demonstrate that large-sized, three-dimensional bulk artificial nacre with comprehensive mimicry of the hierarchical structures and the toughening mechanisms of natural nacre can be facilely fabricated via a bottom-up assembly process based on laminating pre-fabricated two-dimensional nacre-mimetic films. By optimizing the hierarchical architecture from molecular level to macroscopic level, the mechanical performance of the artificial nacre is superior to that of natural nacre and many engineering materials. This bottom-up strategy has no size restriction or fundamental barrier for further scale-up, and can be easily extended to other material systems, opening an avenue for mass production of high-performance bulk nacre-mimetic structural materials in an efficient and cost-effective way for practical applications.Artificial materials that replicate the mechanical properties of nacre represent important structural materials, but are difficult to produce in bulk. Here, the authors exploit the bottom-up assembly of 2D nacre-mimetic films to fabricate 3D bulk artificial nacre with an optimized architecture and excellent mechanical properties.
Ultrathick electrode design is a promising strategy to enhance the specific energy of Li‐ion batteries (LIBs) without changing the underlying materials chemistry. However, the low Li‐ion conductivity ...caused by ultralong Li‐ion transport pathway in traditional random microstructured electrode heavily deteriorates the rate performance of ultrathick electrodes. Herein, inspired by the vertical microchannels in natural wood as the highway for water transport, the microstructures of wood are successfully duplicated into ultrathick bulk LiCoO2 (LCO) cathode via a sol–gel process to achieve the high areal capacity and excellent rate capability. The X‐ray‐based microtomography demonstrates that the uniform microchannels are built up throughout the whole wood‐templated LCO cathode bringing in 1.5 times lower of tortuosity and ≈2 times higher of Li‐ion conductivity compared to that of random structured LCO cathode. The fabricated wood‐inspired LCO cathode delivers high areal capacity up to 22.7 mAh cm−2 (five times of the existing electrode) and achieves the dynamic stress test at such high areal capacity for the first time. The reported wood‐inspired design will open a new avenue to adopt natural hierarchical structures to improve the performance of LIBs.
Inspired by the vertical microchannels in natural wood as the highway for water transport, an ultra‐thick bulk LiCoO2 (LCO) cathode with vertical channels is fabricated to enhance the transport of Li+. Remarkably, the fabricated LCO cathode shows low tortuosity and high Li‐ion conductivity, and can deliver high areal capacity up to 22.7 mAh cm−2.
Ultrathin nanostructures are attractive for diverse applications owing to their unique properties compared to their bulk materials. Transition‐metal chalcogenides are promising electrocatalysts, yet ...it remains difficult to make ultrathin structures (sub‐2 nm), and the realization of their chemical doping is even more challenging. Herein we describe a soft‐template mediated colloidal synthesis of Fe‐doped NiSe2 ultrathin nanowires (UNWs) with diameter down to 1.7 nm. The synergistic interplay between oleylamine and 1‐dodecanethiol is crucial to yield these UNWs. The in situ formed amorphous hydroxide layers that is confined to the surface of the ultrathin scaffolds enable efficient oxygen evolution electrocatalysis. The UNWs exhibit a very low overpotential of 268 mV at 10 mA cm−2 in 0.1 m KOH, as well as remarkable long‐term stability, representing one of the most efficient noble‐metal‐free catalysts.
Down to the wire: Colloidal Fe‐doped NiSe2 ultrathin nanowires (UNWs) down to 1.7 nm in diameter were synthesized by a binary soft‐template strategy. These UNWs yield surface‐confined electrochemical oxidation, enabling efficient and robust oxygen evolution catalysis owing to their favorable electronic structures and unsaturated local coordination environments.
The exploration of lead‐free halide perovskite nanocrystals (NCs) with intriguing optical properties is highly desirable owing to the toxicity and instability of lead halide perovskite NCs. Here, a ...new kind of uniform lead‐free double perovskite Cs2NaBiCl6 NCs are reported as versatile hosts to accommodate ionic dopants for improving optical properties especially the photoluminescence (PL). In contrast to the low deep‐blue PL with a quantum yield of only 1.7% of the as‐synthesized pristine Cs2NaBiCl6 NCs, the PL of the Cs2NaBiCl6 NCs can be impressively regulated and enhanced via doping Ag+, Mn2+, or Eu3+ ions in the double perovskite lattices. The femtosecond time‐resolved transient absorption spectroscopy is adopted to unravel the PL enhancement mechanism of the ion doping in the Cs2NaBiCl6 NCs. For the Ag+‐doping, the excitonic absorption energy of the Cs2NaBiCl6 NCs can be tuned from 3.82 to 3.48 eV with the significant improvement of the PL quantum yield (PLQY) from 1.7% to 20%. The Mn2+‐doped Cs2NaBiCl6 NCs show broad orange–red emission peak centered at 585 nm with a PLQY of 3%, owing to the 4T1→6A1 transition of octahedrally coordinated Mn2+. Eu3+‐doped Cs2NaBiCl6 NCs are endowed with strong Eu3+5D0→7FJ (J = 1, 2) orange–red emission at 591 and 615 nm.
A series of ions (Ag+, Mn2+, and Eu3+) doped lead‐free double perovskite Cs2NaBiCl6 nanocrystals (NCs) with uniform morphologies and good air stability are synthesized, exhibiting impressively enhanced photoluminescence in comparison to pristine Cs2NaBiCl6 NCs. The ion doping mechanisms for improving the PL are unraveled by the femtosecond time‐resolved transient absorption spectroscopy characterizations as well.
Graphene‐based fibers (GBFs) are attractive for next‐generation wearable electronics due to their potentially high mechanical strength, superior flexibility, and excellent electrical and thermal ...conductivity. Many efforts have been devoted to improving these properties of GBFs in the past few years. However, fabricating GBFs with high strength and electrical conductivity simultaneously remains as a great challenge. Herein, inspired by nacre‐like multilevel structural design, an interface‐reinforced method is developed to improve both the mechanical property and electrical conductivity of the GBFs by introducing polydopamine‐derived N‐doped carbon species as resistance enhancers, binding agents, and conductive connection “bridges.” Remarkably, both the tensile strength and electrical conductivity of the obtained GBFs are significantly improved to ≈724 MPa and ≈6.6 × 104 S m−1, respectively, demonstrating great superiority compared to previously reported similar GBFs. These outstanding integrated performances of the GBFs provide it with great application potential in the fields of flexible and wearable microdevices such as sensors, actuators, supercapacitors, and batteries.
Both the mechanical properties and electrical conductivity of graphene‐based fibers (GBFs) are improved by a novel interface‐reinforced method by introducing polydopamine (PDA)‐derived N‐doped carbon species as resistance enhancers, binding agents, and conductive connection “bridges”. Ultimately, both the tensile strength and electrical conductivity of the obtained GBFs are significantly improved.
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