Materials Today Chemistry
·
2021
·
IF 8.301
Xiaoyong Huang,Shaoying Wang,Balaji Devakumar,Nan Ma
The development of new efficient and environmental-friendly inorganic phosphors is highly important for phosphor-converted white light-emitting diodes and optoelectronic displays. In this paper, we report a novel and simple one-step solid-state reaction to synthesize lead-free cesium copper halide Cs 3 Cu 2 Br 5 powders with bright blue emission around 460 nm. The preparation process is performed at low calcination temperatures (290–320 °C) and requires no complex apparatus, reagents, or techniques, and thus it holds great potential for mass production of halide emitters. The Cs 3 Cu 2 Br 5 powder phosphors are characterized by X-ray diffraction, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, photoluminescence excitation and emission spectroscopy , CIE color coordinates, color purity, photoluminescence quantum yield, and temperature-dependent emission spectra . The effect of calcination temperature on the photoluminescence properties of the as-prepared Cs 3 Cu 2 Br 5 blue phosphors has been investigated and the air-stability property has also been discussed. Impressively, Cs 3 Cu 2 Br 5 blue phosphors show outstanding stability toward air exposure exceeding one month (30 days). Our work will open a new and simple approach to obtain excellent halide emitters for future solid-state lighting and displays.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Magnetic Resonance Letters
·
2023
·
IF 0
Suyu Gu,Guozhong Lu,Nianrui Guo,Juncheng Xu,Yu Jiang,Ming Shen,Bingwen Hu
LiCoO 2 is an important category of active cathode materials in lithium-ion batteries due to its high compacted electrode density, good thermal stability , and stable voltage platform. Recent works on LiCoO 2 have focused on the realization of higher charging voltages to fully utilize its high theoretical capacity. However, an unambiguous atomic-level local probe is essential for the understanding of structure-function correlation. Here we employ high-resolution solid-state nuclear magnetic resonance (NMR) spectroscopy to study the local atomic environments in LiCoO 2 synthesized with three common sintering methods. While one-dimensional 7 Li NMR shows distinct linewidth and subtle dependence on lithium over-stoichiometry, both 7 Li and 59 Co relaxation times are highly dependent on the sintering method. We prove that the two-step sintering method favors the elimination of unreacted Co 3 O 4 , thereby enabling the best discharge capacity in all-solid-state lithium batteries assembled with LiCoO 2 /LGPS/LiIn, which is in accordance with its narrowest 7 Li linewidth and the longest 7 Li/ 59 Co T 1 .
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
Frontiers in Energy Research
·
2021
·
IF 4.008
Zhanjun Chen,Tao Wang,Haijun Yu,Jun Guo,Hongbin Zhong,Chuanyue Hu,Ruirui Zhao,Hongyu Chen
Molten-salt assisted solid-state synthesis is considered a promising method in obtaining layer-structured cathodes for lithium-ion batteries with homogeneous elemental distribution and controllable morphologies. However, drawbacks like resource wasting which have arisen from redundant salt removal after sintering greatly hinder the broader application of this technique. In this paper, a closed-loop utilization of molten salts is proposed for the first time with specific electrochemical properties of the products studied. Results confirm the feasibility of this strategy, and that with only replenishing LiOH, the recycled LiOH-LiCl molten salts can be successfully reused into another LiNi0.5Co0.2Mn0.3O2 synthesis, which exhibits almost equal electrochemical performance to the product using fresh molten salts. We believe this research can provide significant insight in guiding green and environmental-friendly preparation methods involving molten salts.
研究领域:
材料科学
·
电化学
·
能源化学
·
无机化学
·
电池技术
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2024
·
IF 4.5
Huifeng Xu,Pengfei Wang,Saiwei Luan,Lixia Cheng,Zhenxiao Fu,Xiuhua Cao,Lei Zhang,Shuhui Yu,Rong Sun
Conventionally, tetragonality in BaTiO 3 powder is attributed to grain size, disregarding the role of Ba/Ti ratio. However, our study reveals a significant impact of Ba/Ti ratio on tetragonality in BaTiO 3 . With an increase in Ba/Ti ratio from 0.990 to 1.010, particle size remains around 200 nm. Tetragonality initially rises from 1.006 to a maximum of 1.0092 at Ba/Ti = 1.000, then decreases to 1.005. Lower tetragonality is associated with Ba or Ti vacancies, using density functional theory (DFT), we analyzed the electron density and lattice distinction in BaTiO 3 powders. Both Ba and Ti vacancies affect lattice distortion, the Ti vacancies leading to more significant lattice expansion and lower tetragonality than Ba vacancies. Using this powder, we fabricated high-density BaTiO 3 ceramics and multi-layer ceramics capacitors (MLCCs) with X7R temperature stability (−55 to 125 °C, ±15% coefficient) and excellent reliability. This strategy has broad implications for tetragonal BaTiO 3 nanopowders and MLCCs development.
研究领域:
材料科学
·
无机非金属材料
·
电子陶瓷
·
固态化学
·
功能材料
✓ 已验证
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2016
·Vol. 43
·期 1
·341-352
·
IF 1.833
Sun Guangyao,Li Wenjing,Ji Shidong,Cao Xun,Jin Ping
Methanol was used to optimize the solid-state synthesizing method of alkali metavanadates AVO 3 (A = Rb, Cs) for the first time and the benefits are discussed. Due to the optimization, four kinds of heterogeneous AVO 3 compounds, white CsVO 3 [CsVO 3 (W)], yellow CsVO 3 [CsVO 3 (Y)], white RbVO 3 [RbVO 3 (W)], and red RbVO 3 [RbVO 3 (R)], could be easily obtained. The colored compounds CsVO 3 (Y) and RbVO 3 (R) are reported for the first time and their synthetic process has been summarized, while their crystal structure, morphology, vibration spectroscopy, photoluminescence, moisture adsorption and thermodynamic properties were measured and compared to white compounds. The differences in properties of CsVO 3 (Y) and RbVO 3 (R) were hypothesized as the oriented growth and induced defects. All four AVO 3 compounds were excellent white-light-emitting phosphors, and CsVO 3 (Y) and RbVO 3 (R), with additional waterproofness, suggested much more practical value.
研究领域:
无机化学
·
材料科学
·
固体化学
·
发光材料
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Lingjun Li,Lingfeng Xia,Huiping Yang,Xuehui Zhan,Jie Chen,Zhaoyong Chen,Junfei Duan
The high voltage application of the LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathode is still hindered by its unstable surficial structure and poor capacity retention. Surface coating has been proved to be an effective strategy to deal with these problems. However, previous multistep surface coating approaches greatly complicate the synthesis procedure. In this work, a simple and large-scale solid-state approach is developed to prepare lanthanum-based oxides co-coated LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathode materials . Electrochemical tests indicate that the co-coated samples exhibit superior cycle life and higher rate performance than those of the pristine sample. Further studies reveal that the enhanced interface stability and facilitated electron transportation can be attributed to the synergetic contribution provided by the lanthanum-based oxides co-coating layer. The present work demonstrates that our approach can achieve cathode synthesis and surface coating synchronously, and shows great potential to apply on a large scale and extent to all Ni-rich cathodes.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
功能材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）