A novel technique to prepare carbon/sulfur composites as cathode materials for Li/S batteries is proposed, which we call the ‘solution evaporation concentration crystallization’ method. Three composites with different S loadings were prepared, subject to two different solvent evaporation rates from acetylene black (AB)/sulfur in carbon disulfide solutions. X-ray diffraction, environmental scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller measurements all show that the porous AB structure is well-filled with S. Composites prepared at a lower solvent evaporation rate with 50 wt % S content, had good electrochemical properties, with 1609.67 mAh g−1in the initial cycle and 1115.69 mAh g−1after 100 cycles. Composites with better dispersibility at a low solvent evaporation rate can effectively prevent polysulfide from dissolving in the electrolyte, and serve to stabilize the structure of the S cathode during the charge-discharge process.Keywords:sulfur/carbon composites;solution evaporation concentration crystallization method;lithium sulfur batteries
D.D. Liu,N.S. Yu,D.P. Liu,Y.Y. He,R. Liu,Q.J. Li,B. Liu,B.B. Liu
C 60 nano/microcrystals were synthesized from fullerene dissolved in three different trichlorobenzene isomers, to investigate the role of solvent as both shape and morphology controller in the synthesis of C 60 nanocrystals. Various C 60 nano/microcrystals, in particle-, sheet-, cuboid- and rod morphologies have been selectively fabricated at 80 °C using either solution evaporation or solution mixing method. The molecular structure of trichlorobenzene solvent plays a key role in the formation of different crystal morphologies, and also affects the crystal structure of synthesized samples.
Ying Chen,Minghao Li,Jing Huang,Hui Zeng,Linhua Xu,Jing Su
This paper presents the growth of large-sized CsCu(Br, Cl) 3 crystals using the aqueous solution evaporation method. The structure and the components of the crystals were analyzed. It was found that CsCuBr 3 is a direct bandgap material, while CsCuCl 3 is an indirect bandgap material, and the band gap of CsCu(Br, Cl) 3 halides can be adjusted in the range of 2.63–3.63 eV (PBE) by changing the ratio of Br - /Cl - . Besides CsCuCl 3, which has an absorption valley at 654 nm, the other CsCu(Br, Cl) 3 crystals show high absorption in the range of 200–1000 nm. Under UV excitation, the PL spectra show that CsCu(Br, Cl) 3 crystals exhibit red and blue emission.
Aqiang Liu,Kang Liu,Huimin Zhou,Hongmei Li,Xiaoqing Qiu,Yi Yang,Min Liu
Organic-inorganic hybrid perovskite solar cells (PSCs), due to their high power conversion efficiency (PCE) and low cost, have been considered as one of the most promising photovoltaic devices . Well-distributed large-grain perovskite crystals play an important role for light adsorption and charge transfer. While, high quality perovskite crystals closely relate to the preparation method. Generally, the preparation of perovskite films requires a nitrogen atmosphere and toxic anti-solvents, which hinder their practical applications. Here, we reported a novel and simple solution evaporation process followed with a methylammonium iodide (MAI) solution immersion to prepare high quality perovskite films. Porous lead iodide (PbI 2 ) films were firstly formed by evaporation of PbI 2 precursor solution . The obtained porous PbI 2 films were completely transformed into well-distributed large-grain perovskite films after a quick MAI solution immersion. As a result, the corresponding PCE was enhanced by 30% compared to that prepared with a regular sequential deposition. This solution evaporation method provides a convenient and practical way for preparing high-quality perovskite films.
危险品化学品经营许可证（带存储）