CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Jin Feng,Rongxia Huang,Zhihao Liang,Zuchao Du,Yejing Dai,Jianbo Wu,Hua-Tay Lin
This research explored the influence of Nb 5+ doping on the electrical properties and microstructure of [0.852(Bi 0.5 Na 0.5 )-0.11(Bi 0.5 K 0.5 )-0.038Ba]Ti (1- x ) Nb x O 3 (designated as BNKT-BT). The BNKT-BT samples were fabricated and the XRD results showed that the doping of Nb 5+ ions induced a transformation from the coexistence of both rhombohedral and tetragonal phase to a single pseudo cubic phase. Also, the doping of Nb 5+ ions caused the temperature of ferroelectric state-ergodic relaxor state transition to decrease below the room temperature (RT). The SEM observations showed that the Nb 5+ doping had a minor effect on the grain size of BNKT-BT samples. In addition, the samples achieved a large electrostrain of 0.43% ( d * 33 = S max / E max = 614 pm/V) under 7 kV/mm at RT. Moreover, the aging process employed at 80 °C for two weeks in air could effectively increase the electrostrain from 0.38% to 0.41% under 6 kV/mm ( d * 33 = 683 pm/V) and reduce the strain hysteresis from 57% to 34%. These results indicated that the B site doping, combined with the aging process, could provide an effective way to enhance the electrostrain performance of lead-free piezoelectric ceramics.
研究领域:
材料科学
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物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2022
·Vol. 106
·期 2
·1413-1423
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IF 4.186
Yameng Zhu,Jinpeng Zhu,Hailong Wang,Kaijun Yang,Mingliang Li,Jilin He
Thermal protection materials with high optical reflectivity, low thermal conductivity, and good high-temperature stability are required for the development of laser technologies and the protection of the critical equipment components. Herein, we synthesize a novel thermal protective material, La 0.9 Sr 0.1 Ti 1− x Nb x O 3+ δ (LSTN; x = 0.1, 0.125, 0.15), with different Nb 5+ -ion contents using solid-state sintering. Phase structure analysis demonstrates that LSTN ( x = 0.1, 0.125, 0.15) presents a single-phase monoclinic structure with a uniform element distribution. In particular, the LSTN 0.125 ceramic exhibits ultrahigh optical reflectivity (96%, 2300 nm) and excellent thermophysical properties, such as a high thermal expansion coefficient (10.3 × 10 −6 K −1 , 1000°C), an ultralow thermal conductivity (0.408 W (m K) −1 , 300°C), and excellent high-temperature stability. Aberration-corrected scanning transmission electron microscopy reveals that the disordered substitution of Nb 5+ ions induces numerous lattice distortions and mass fluctuations, which decrease the thermal conductivity, and makes difference in the relative refractive indices of atomic layers causing the high reflectivity of the material. These remarkable properties render the LSTN 0.125 ceramic as an ideal alternative for near-infrared thermal protection applications.
研究领域:
材料科学
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物理学
✓ 已验证
产品关联
DOI
高影响因子
Interdisciplinary Materials
·
2025
·Vol. 4
·期 6
·914-926
·
IF 31.6
Wanqing Ren,Yang Li,Xingyi Peng,Meng Wu,Xiang Qi,Peng Lei,Changyi Fan,Ce-Wen Nan,Li-Zhen Fan
Zirconium-based halide electrolytes were created as prospective candidates for all-solid-state lithium batteries (ASSLBs) because of their low cost, wide electrochemical window, and superior compatibility with oxide cathodes. However, practical implementation is hindered by limitations such as suboptimal room-temperature (RT) ionic conductivity (< 1 mS cm −1 ) and poor interfacial compatibility with lithium metal. Herein, we report a new class of zirconium-based chlorides, Li 2− x Zr 1− x Nb x Cl 6 , synthesized by a high-valent Nb 5+ doping method. The introduction of Nb 5+ induces local lattice decrease, which simultaneously weakens the binding intensity of Li─Zr and optimizes ion migration pathways and defect concentrations. Therefore, the optimal composition, Li 1.75 Zr 0.75 Nb 0.25 Cl 6 (denoted as LZC-Nb), achieves a high RT ionic conductivity of 1.82 mS cm −1 and exceptional moisture resistance. Furthermore, the dynamic interfacial modulation of LZC-Nb forms a low-impedance passivation layer, enhancing Li + transport kinetics. This improvement in interfacial stability enables symmetric batteries to exceed a critical current density of 1.3 mA cm −2 . Combined with a LiNi 0.8 Mn 0.1 Co 0.1 O 2 cathode, the resultant ASSLB retains 81.8% of its initial capacity (157.5 mAh g −1 ) after 600 cycles at 0.3 C. This study provides a proven strategy for developing inorganic ionic conductors with superior ionic transport and interfacial compatibility, offering a viable pathway toward high-performance ASSLBs.
研究领域:
材料科学
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电化学
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储能
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固体离子学
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电池技术
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Hao Wang,Yanju Wei,Jitong Wang,Donghui Long
Submicrometer-sized LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM111) crystals with homogeneous composition are prepared via a polymer-chelation chemical solution process. The complexed chelate agents of ethylenediaminetetraacetic acid (EDTA) and polyethyleneimine (PEI) could chelate all metal ions in one step, with intimate mixing at the atomic level, ensuring a homogeneous ion distribution in the product. The as-prepared NCM111 crystals have a narrow particle size distribution with an average size of 250 nm, which can effectively shorten the lithium ion diffusion path. In addition, the NCM111 crystals majorly consist of electrochemically active {010} facets and low Li + /Ni 2+ cation mixing, thus delivering a high reversible discharge capacity of 156.1 mAh g −1 after 100th cycles and good rate capability of 102.7 mAh g −1 at 10 C. Furthermore, it is found that the induction of excess Li could deteriorate the rate capability and increase the Li + solid-state diffusion resistance. However, Al 3+ doping could effectively improve the cycling performance, while Nb 5+ doping could increase significantly the discharge capacity as well as rate capability. Owing to the flexibility of the chelating chemistry , the synthesis should be extended to prepare other multicomponent single-crystal cathodes with homogeneous composition and desired substation.
研究领域:
材料科学
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化学
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电化学
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电池技术
✓ 已验证
DOI
高影响因子
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