Electrochemically Induced Phase Transformation in Vanadium Oxide Boosts Zn-Ion Intercalation.

Vanadium oxides are excellent cathode materials with large storage capacities for aqueous zinc-ion batteries, but their further development has been hampered by their low electronic conductivity and slow Zn diffusion. Here, an electrochemically induced phase transformation strategy is proposed to mitigate and overcome these barriers. X-ray diffraction analysis confirms the complete transformation of tunnel-like structural VO into layered VO·6HO during the initial electrochemical charging process.

Oxygen Vacancies on NH V O Accelerate Ion and Charge Transfer in Aqueous Zinc-Ion Batteries.

Vanadium-based compounds are identified as promising cathode materials for aqueous zinc ion batteries due to their high specific capacity. However, the low intrinsic conductivity and sluggish Zn diffusion kinetics seriously impede their further practical application. Here, oxygen vacancies on NH V O is reported as a high-performing cathode material for aqueous zinc ion batteries via a facile hydrothermal strategy.

Addition of Dioxane in Electrolyte Promotes (002)-Textured Zinc Growth and Suppressed Side Reactions in Zinc-Ion Batteries.

The reversibility and cyclability of aqueous zinc-ion batteries (ZIBs) are largely determined by the stabilization of the Zn anode. Therefore, a stable anode/electrolyte interface capable of inhibiting dendrites and side reactions is crucial for high-performing ZIBs. In this study, we investigated the adsorption of 1,4-dioxane (DX) to promote the exposure of Zn (002) facets and prevent dendrite growth.

Hierarchical Porous Metallic VO@C for Advanced Aqueous Zinc-Ion Batteries.

Aqueous Zn-ion batteries (ZIBs) are a potential electrochemical energy storage device because of their highly intrinsic safety, low cost, and large capacity. However, it is still in the primary stage because of the limited selection of cathode materials with high rate and long-life cycling stability. In addition, the energy storage mechanisms of ZIBs have not been well established.

Adjusting the Introduction of Cations for Highly Efficient and Stable Perovskite Solar Cells Based on (FAPbI ) (FAPbBr ).

Although the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has increased to 22.7 %, the instability when exposed to moisture and heat has hindered their further practical development. In this study, to gain highly efficient and stable perovskite components, methylammonium (MA), Cs, and Rb cations are introduced into a (FAPbI ) (FAPbBr ) (FA=formamidine) film, which is rarely used because of its poor photovoltaic performance.

Solvothermal Synthesis of Hierarchical TiO Microstructures with High Crystallinity and Superior Light Scattering for High-Performance Dye-Sensitized Solar Cells.

In this article, hierarchical TiO microstructures (HM-TiO) were synthesized by a simple solvothermal method adopting tetra-n-butyl titanate as the titanium source in a mixed solvent composed of N,N-dimethylformamide and acetic acid. Due to the high crystallinity and superior light-scattering ability, the resultant HM-TiO are advantageous as photoanodes for dye-sensitized solar cells. When assembled to the entire photovoltaic device with C101 dye as a sensitizer, the pure HM-TiO-based solar cells showed an ultrahigh photovoltage up to 0.

Enhancing the Photovoltaic Performance of Perovskite Solar Cells with a Down-Conversion Eu-Complex.

Organometal halide perovskite solar cells (PSCs) have shown high photovoltaic performance but poor utilization of ultraviolet (UV) irradiation. Lanthanide complexes have a wide absorption range in the UV region and they can down-convert the absorbed UV light into visible light, which provides a possibility for PSCs to utilize UV light for higher photocurrent, efficiency, and stability. In this study, we use a transparent luminescent down-converting layer (LDL) of Eu-4,7-diphenyl-1,10-phenanthroline (Eu-complex) to improve the light utilization efficiency of PSCs.

TiO hierarchical sub-wavelength microspheres for high efficiency dye-sensitized solar cells.

Monodisperse anatase hierarchical microspheres were produced via a simple sol-gel process. These microspheres in the sub-wavelength diameter of 320-750 nm could scatter visible light efficiently as whispering gallery modes (WGM) corresponding to the dye sensitized wavelength, and load a large number of dye molecules with a large surface area (149.82 m g).

Trap States Comparison of Mesoporous TiO2 Photoanodes with Different Particle Sizes.

For the dye-sensitized solar cells (DSSCs), trap states exist in the TiO2 based photoanode and play an important role on the dynamic process of charge transport and recombination in the DSSCs. Generally, trap states mainly result from impurities, interface adsorption of ions, the breakdown of the lattice periodicity in the semiconductor, dangling bonds and/or the rearrangement of surface atoms. In this paper, we compare trap states of different nanoparticles based TiO2 photoanode films.

High Performance Dye-Sensitized Solar Cells with Enhanced Light-Harvesting Efficiency Based on Polyvinylpyrrolidone-Coated Au-TiO2 Microspheres.

Surface plasmon resonance using noble metal nanoparticles is regarded as an attractive and viable strategy to improve the optical absorption and/or photocurrent in dye-sensitized solar cells (DSSCs). However, no significant improvement in device performance has been observed. The bottleneck is the stability of the noble-metal nanoparticles caused by chemical corrosion.

Fine Tuning of Nanocrystal and Pore Sizes of TiO2 Submicrospheres toward High Performance Dye-Sensitized Solar Cells.

In general, the properties and performance of mesoporous TiO2 are greatly dependent on its crystal size, crystallinity, porosity, surface area, and morphology; in this regard, design and fine-tuning the crystal and pore sizes of the TiO2 submicrospheres and investigating the effect of these factors on the properties and photoelectric performance of dye-sensitized solar cells (DSSCs) is essential. In this work, uniform TiO2 submicrospheres were synthesized by a two-step procedure containing hydrolysis and solvothermal process. The crystal and pore sizes of the TiO2 submicrospheres were fine-tuned and controlled in a narrow range by adjusting the quantity of NH4OH during the solvothermal process.

Mesoporous TiO2 Yolk-Shell Microspheres for Dye-sensitized Solar Cells with a High Efficiency Exceeding 11%.

Yolk-shell TiO2 microspheres were synthesized via a one-pot template-free solvothermal method building on the aldol condensation reaction of acetylacetone. This unique structure shows superior light scattering ability resulting in power conversion efficiency as high as 11%. This work provided a new synthesis system for TiO2 microspheres from solid to hollow and a novel material platform for high performance solar cells.

One-Pot Synthesis of Mesoporous TiO₂ Micropheres and Its Application for High-Efficiency Dye-Sensitized Solar Cells.

TiO2 microspheres are of great interest for a great deal of applications, especially in the solar cell field. Because of their unique microstructure and light-scattering effect, TiO2 microsphere-based solar cells often exhibit superior photovoltaic performance. Hence, exploring new suitable TiO2 microspheres for high-efficiency solar cells is essential.

A study on formation of titanium oxide nanoribbons.

The transformation process of nanoribbons produced by the hydrothermal treatment in 10 M NaOH solution at 200 degrees C was investigated systematically via electron microscopy. Field emission scanning electron microscope (FE-SEM) observation showed that the treatment duration had a strong effect on the product morphology from the hollow nanotubes to nanoribbons. The details of transformation were studied by transmission electron miscroscopy.