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1.
J Am Chem Soc ; 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32045234

RESUMO

Highly luminescent inks are desirable for various applications such as decorative coating, art painting, and anticounterfeiting, to name a few. However, present inks display low photoluminescent efficiency requiring a strong excitation light to make them glow. Here, we report a highly luminescent ink based on the copper-iodide/1-Propyl-1,4-diazabicyclo[2.2.2]octan-1-ium (Cu4I6(pr-ted)2) hybrid cluster with a quantum efficiency exceeding 98%. Under the interaction between the Cu4I6(pr-ted)2 hybrid cluster and polyvinylpyrrolidone (PVP), the highly luminescent Cu4I6(pr-ted)2/PVP ink can be facilely prepared via the one-pot solution synthesis. The obtained ink exhibits strong green light emission that originates from the efficient phosphorescence of Cu4I6(pr-ted)2 nanocrystals. Attractively, the ink displays high conversion efficiency for the ultraviolet light to bright green light emission due to its wide Stokes shift, implying great potential for anticounterfeiting and luminescent solar concentrator coating.

2.
Nano Lett ; 20(1): 677-685, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31825636

RESUMO

Lithium cobalt oxide (LiCoO2) possesses an attractive theoretical specific capacity (274 mAh g-1) and high discharge voltage (∼4.2 V vs Li+/Li). However, only a half of the theoretical capacity of LiCoO2 is available in commercialized lithium ion batteries because of the intrinsic structural instability and detrimental interface of LiCoO2 at the charging voltage over 4.2 V. Here, a facile blow-spinning synthetic method is developed to realize precise doping and simultaneous self-assembly coating of LiCoO2 particles, achieving a record performance among present LiCoO2 cathodes. Owing to the spatial confinement effect of microfibers fabricated by blow-spinning, homogeneously Mn and La doped in the LiCoO2 host and uniformly Li-Ti-O segregated at the LiCoO2 surface can be realized in every batch of samples. It is demonstrated that the Mn and La codoping can suspend the intrinsic instability and increase the Li+ diffusivity of the LiCoO2 host, and the Ti-based coating can stabilize the interface of LiCoO2 particles at the charging voltage up to 4.5 V. As a result, the obtained comodified LiCoO2 cathode shows the best rate performance (1.85 mAh cm-2 at 2C) and longest cycling stability under an areal capacity of 2.04 mAh cm-2 (83% capacity retention over 300 cycles at 0.3C), in comparison to previously reported LiCoO2 cathodes.

3.
Adv Mater ; 31(51): e1905711, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31693256

RESUMO

The commercial ceramic nanoparticle coated microporous polyolefin separators used in lithium batteries are still vulnerable under external impact, which may cause short circuits and consequently severe safety threats, because the protective ceramic nanoparticle coating layers on the separators are intrinsically brittle. Here, a nacre-inspired coating on the separator to improve the impact tolerance of lithium batteries is reported. Instead of a random structured ceramic nanoparticle layer, ion-conductive porous multilayers consisting of highly oriented aragonite platelets are coated on the separator. The nacre-inspired coating can sustain external impact by turning the violent localized stress into lower and more uniform stress due to the platelet sliding. A lithium-metal pouch cell using the aragonite platelet coated separator exhibits good cycling stability under external shock, which is in sharp contrast to the fast short circuit of a lithium-metal pouch cell using a commercial ceramic nanoparticle coated separator.

4.
Inorg Chem ; 58(17): 11807-11818, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31398054

RESUMO

Lead halide perovskite nanocrystals (NCs) exhibit great application potential in optoelectronic devices because of their tunable band gaps and facile colloidal synthesis, but they suffer from serious lead toxicity and instability. It is highly desirable to substitute lead with other elements to acquire nontoxic and environmentally friendly lead-free perovskite NCs for optoelectronic devices. Here, we report a general method for the colloidal synthesis of a series of bismuth/antimony-based halide perovskite NCs with various constituents and optical band gaps from 1.97 to 3.15 eV. In our proposed synthetic system, 1-dodecanol is adopted as the solvent instead of the conventionally used 1-octadecene to realize size controllability of bismuth/antimony-based metal halide perovskite NCs. It is found that 1-dodecanol can act as a surfactant to tightly adsorb on the surface of bismuth/antimony-based halide perovskite NCs, enabling their small sizes (∼2 nm) and high dispersibility. Simultaneously, the band gaps of bismuth/antimony-based halide (A3B2X9, where A = CH3NH3, Cs, or Rb, B = Bi or Sb, and X = Cl, Br, or I) perovskite NCs can be systematically tuned by the atomic substitution of A, B, or X lattice sites. Moreover, to show the optoelectronic application potential of these lead-free halide perovskite NCs, a solar cell based on colloidal Cs3Bi2I9 perovskite NCs is demonstrated. The developed colloidal synthesis of bismuth/antimony-based halide NCs in 1-dodecanol will offer an alternative route to fabricating lead-free halide perovskite optoelectronic devices.

5.
Chem Commun (Camb) ; 55(53): 7703-7706, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31204744

RESUMO

Two-dimensional (2D) boron nitride nanosheets (BNNSs) were chemically exfoliated from bulk boron nitride and coated onto the surface of a poly(ethylene oxide) (PEO)-based electrolyte through a dry-pressing transfer process. The fabricated BNNSs coating formed a robust interfacial layer to improve the chemical and mechanical stability of the PEO-based electrolyte, leading to the enhanced performance of solid-state Li metal batteries.

6.
Nat Commun ; 10(1): 2482, 2019 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-31171790

RESUMO

Lithium metal based anode with hierarchical structure to enable high rate capability, volume change accommodation, and dendritic suppression is highly desirable for all-solid-state lithium metal battery. However, the fabrication of hierarchical lithium metal based anode is challenging due to the volatility of lithium. Here, we report that natural diatomite can act as an excellent template for constructing hierarchical silicon-lithium based hybrid anode for high performance all-solid-state lithium metal battery. This hybrid anode exhibits stable lithium stripping/plating performance over 1000 h with average overpotential lower than 100 mV without any short circuit. Moreover, all-solid-state full cell using this lithium metal composite anode to couple with lithium iron phosphate cathode shows excellent cycling stability (0.04% capacity decay rate for 500 cycles at 0.5C) and high rate capability (65 mAh g-1 at 5C). The present natural diatomite derived hybrid anode could further promote the fabrication of high performance all-solid-state lithium batteries from sustainable natural resources.

7.
Nanoscale ; 10(41): 19262-19271, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30324957

RESUMO

Although the efficiency of metal halide perovskite light emitting diodes (PeLEDs) has been improved to an attractive level, the poor stability of perovskite emitting layers is a major concern for the application of PeLEDs. Herein, we report a facile ligand-assisted precipitation synthesis of stable dual-phase CsPbBr3-CsPb2Br5 nanocrystals (NCs) for improving the stability of PeLEDs. In our synthetic process, the bromide-rich circumstance is beneficial to generate high quality dual-phase perovskite NCs with PLQY as high as 92% and a narrow emission linewidth (19 nm). More importantly, as-synthesized dual phase perovskite NCs exhibit extremely high thermal stability in heating tests in air with a considerable humidity of 30%-55% in comparison with previously reported single phase CsPbBr3 NCs. The aforementioned advantages of our synthesized dual-phase CsPbBr3-CsPb2Br5 NCs allow for the fabrication of light emitting layers of PeLEDs under ambient conditions. The fabricated green PeLED based on CsPbBr3-CsPb2Br5 NCs shows a low turn-on voltage of 2.5 V and a high brightness of 8383 cd m-2 at 8 V. Owing to the high stability of dual-phase CsPbBr3-CsPb2Br5 NCs, the fabricated PeLED also exhibits better operational stability in comparison with those PeLEDs based on single phase CsPbBr3 NCs. Our work presents a new route to fabricate stable perovskite light-emitting diodes using room temperature precipitated dual-phase CsPbBr3-CsPb2Br5 NCs as emitting layer materials.

8.
Angew Chem Int Ed Engl ; 57(24): 7106-7110, 2018 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-29722463

RESUMO

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 (Cu4 I4 (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.

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