JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2020
·
IF 4.495
Jing Wang,Xinhong Wan,Yu Rao,Lei Zhao,Kongjun Zhu
Silver niobate AgNbO 3 ceramics have been regarded as a promising lead-free material for energy storage applications. In present work, pure and fine AgNbO 3 powders were successfully fabricated via the hydrothermal method using AgNO 3 as the raw material. It is found that the reaction products show strong dependence on the molar ratio of NH 4 HF 2 :AgNO 3 :Nb 2 O 5 , pH value and reaction time. Pure AgNbO 3 powders were obtained when the process conditions are 3NH 4 HF 2 :2AgNO 3 : x Nb 2 O 5 with x ≤0.85 or y NH 4 HF 2 :2AgNO 3 :1Nb 2 O 5 with y = 4–5, pH = 5 and reaction time t ≥ 10 h. Benefitting from the hydrothermal synthesised AgNbO 3 powders, AgNbO 3 ceramics with fine-grain of ∼3.4 μm were obtained. The fine-grain leads to increased electric breakdown strength E b up to 250 kV/cm, which is the highest among the pure AgNbO 3 ceramics to our best knowledge. The further enhancement in E b and recoverable energy density could be highly anticipated if the antiferroelectric phase could be stabilized.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 4
·2437-2445
·
IF 3.361
Heng Xu,Jianghu Liang,Zhanfei Zhang,Zihao Deng,Yuankun Qiu,Maosheng He,Jianli Wang,Yajuan Yang,Chun-Chao Chen
Cesium lead halide perovskite nanocrystals (NCs) have attracted extensive attention for photoelectric device application due to their excellent optoelectronic properties. However, the toxicity of lead has hindered their commercialization. Consequently, lead free cesium metal halide NCs have been developed, but these materials suffer from low photoluminescence quantum yield (PLQY) and poor stability. Here, a new class of lead-free non-perovskite blue-emitting cesium bromine (CsBr) and cesium iodine (CsI) halide NCs are realized by zinc doping. High PLQYs of 79.05% and 78.95% are achieved by CsBr:Zn and CsI:Zn NCs, respectively, attributed to the improved local structural order and reduced strain between the lattices of the NCs after storing under ambient conditions for 20 to 30 days. Moreover, zinc doped cesium halide NCs show excellent air stability for at least 50 days. Our results for zinc doped cesium halide NCs have shown a new avenue to fabricate lead-free halide NCs for blue lighting and display applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Boying Wang,Hao Wang,Jiantao Wang,Chaolong Li,Feng Wang,Chunli Diao,Haiwu Zheng
Dielectric thin film capacitors are expected to be a promising candidate for high-performance energy storage devices due to their high power density, fast charge/discharge speed, and excellent stability. Nevertheless, it remains a challenging endeavor to develop dielectrics with excellent energy storage density comparable to that of commercial batteries. In this work, lead-free 0.8SrTiO 3 -0.2BiFeO 3 (0.8STO-0.2BFO) thin films with coexisting amorphous and nanocrystalline structure were prepared by a sol-gel method. The heat-treatment temperature was adjusted to form polar-nano regions, thereby modulate the breakdown strength and dielectric polarization, and increase the energy storage density. The electric potential, electric field, and current density of the films with different amorphous/crystalline volume fractions were evaluated by the finite element simulation to further verify that the proper crystallization can result in the improved polarization performance and increased breakdown strength of the films, which are beneficial to the enhancement of energy storage performance. Through structural tailoring, the 0.8STO-0.2BFO film annealed at 550 °C demonstrates the optimal energy storage properties with a giant discharge energy storage density of 65 J/cm 3 and high efficiency of 75% at room temperature. Simultaneously, a broad temperature stability (20–160 °C), superb operating frequency stability (20 Hz-2 kHz), and excellent fatigue endurance (6.3 ×10 5 ) are observed without appreciable degradation of the energy storage performance. The excellent energy storage performance indicates a widespread potential of 0.8STO-0.2BFO films in pulse power applications, such as consumer electronics, microelectronics, and medical devices .
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2023
·Vol. 10
·期 7
·2039-2044
·
IF 7
Weiqi Huang,Xiaolong Wu,Belal Ahmed,Yanqiang Li,Yang Zhou,Han Wang,Yipeng Song,Xiaojun Kuang,Junhua Luo,Sangen Zhao
Birefringent crystals have important applications in optoelectronics due to their ability to modulate and polarize light. Hybrid halide perovskites were not considered as promising candidates for birefringent crystals until quite recently, when we reported a hybrid lead bromine perovskite with large birefringence. Herein, we report a novel lead-free hybrid pseudo-perovskite layered structure of MLASnCl4 (MLA = melamine). Remarkably, MLASnCl4 reveals a large birefringence of 0.294@550 nm, which is comparable to that of the previously reported hybrid lead bromine perovskite MLAPbBr4. Furthermore, the surface morphologies of the reported crystals exhibit excellent air stability investigated by their exposure to air at room temperature for various time ranges. The observed birefringence is generated from the delocalized π-conjugations of melamine cations and stereochemically active lone pair electrons on the Sn2+ cations of highly distorted SnCl4 tetrahedra, as suggested by theoretical calculations. This current research effort may open new windows for the design of hybrid perovskite materials for polarization-dependent optical applications.
研究领域:
材料科学
·
光学
·
无机化学
·
凝聚态物理
·
功能材料
✓ 已验证
DOI
高影响因子
Materials Today Physics
·
2023
·
IF 11.5
Ruifan Si,Zhongwei Zhang,Chengyan Liu,Ying Peng,Xiaobo Bai,Baoquan Feng,Junliang Chen,Jie Gao,Lei Miao
With developing of thermoelectric (TE) performance, GeTe-based TE materials present great promising application at medium temperatures as a replacement for toxic PbTe. However, the further improvement of TE properties is severely constrained by the coupling of electron and phonon transport. In this study, we achieve decoupled electron and phonon transport by effectively creating a special phase boundary to scatter phonon but transmit electron by implanting multi-walled carbon nanotubes (MWCNTs) into Bi-doped GeTe. With the help of this decoupling mechanism, the power factor is effectively improved and reaches up to ∼4482 μW −1 m −1 K −2 at 673 K while the thermal conductivity shows an obvious drop to ∼1.27 W m −1 K −1 at 723 K, leading to an impressive increase in zT to a maximum value of ∼2.3 at 723 K. In particular, a competitive average zT value of ∼1.43 in the temperature range of 323–773 K is obtained, which is at a high level in lead-free GeTe-based materials. Our method could be used as a guidance for the decoupling of electron and phonon transport in other TE materials .
研究领域:
材料科学
·
凝聚态物理
·
能源材料
·
热电转换
·
纳米复合材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）