JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Xinglong Liu,Zexing Wang,Xinyao She,Quanliang Jia,Jiamao Li
In this study, LiF was utilized to decrease sintering temperature , improve microstructure, enhance Q × f , and regulate τ f of Li 2 Ti 0.9 (Zn 1/3 Ta 2/3 ) 0.1 O 3 (abbreviated as LTZT) ceramics. A complete solid solution together with a phase transition from monoclinic to cubic rock salt structure occurred. The cell volume of LTZT ceramics decreased as the LiF content increased. Relatively dense and uniform microstructures were observed for the ceramics as the LiF content was not less than 2 wt%. The dielectric constant of LTZT ceramics initially increased and then decreased with the increasing LiF content. The FWHM of the Raman band at about 808 cm −1 was closely related to the Q × f value. Notably, the samples with 3 wt% LiF exhibited the highest relative density of 97.4 % and satisfactory microwave dielectric properties of ε r = 23.14 ± 0.16, Q × f = 110,090 ± 1100 GHz, and τ f = +3.25 ± 1.45 ppm/°C when sintered at 950 °C. Good chemical compatibility with silver indicated the ceramic is a promising candidate in LTCC applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Tiantian Gao,Bo Wang,Jinlong Gao,Dianlong Wang
Lithium metal is considered to be one of the most promising anode materials for next-generation energy storage systems. However, low Coulombic efficiency and dendrite growth during cycling limit the practical applications of lithium metal. In this work, a non-combustible inorganic electrolyte-LiAlCl 4 · 3SO 2 is modified with LiF additive to achieve a more stable lithium metal anode . By adding 0.3 wt % LiF to LiAlCl 4 · 3SO 2 , the ionic conductivity and lithium ion transference number of LiAlCl 4 · 3SO 2 are increased, and lithium ion migration through the solid electrolyte interface (SEI) film of lithium metal anode is easier. Thus, a more stable lithium metal anode is achieved. Therefore, at 2.0 mA cm −2 and 2.0 mAh·cm −2 , Li|Cu cells with LiAlCl 4 · 3SO 2 containing 0.3 wt % LiF can provide a stable cycling for 310 h with an average Coulombic efficiency up to 97.0%. Moreover, the addition of 0.3 wt % LiF in LiAlCl 4 · 3SO 2 can also improve the electrochemical performance of Li-SO 2 full-cell. With an areal capacity of 2 mAh·cm −2 , Li-SO 2 cell with LiAlCl 4 · 3SO 2 containing 0.3 wt % LiF can deliver ∼900 mAh·g (carbon) −1 at a discharge current densities of 0.5 A g (carbon) −1 . Therefore, we believe that a simple and effective solution is provided in this work to improve the stability of lithium metal anode with LiAlCl 4 · 3SO 2 inorganic electrolyte.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Xiaodong Zhu,Fantao Kong,Xinsheng Ma
Li-added CaO-B 2 O 3 -SiO 2 (CBS) dielectric microwave substrates for low temperature co-fired ceramic (LTCC) applications were prepared using a solid-state reaction, and the effect of the LiF additive on the sintering behavior, dielectric performance and mechanical properties of the product was investigated. In this presently reported work, we found that the LiF additive could effectually reduce the sintering temperature of the CBS ceramics and also substantially improved the densification, dielectric and mechanical properties of it. The experimental results showed that an addition of 3 wt% LiF to the sample sintered at 790 °C resulted in a main crystalline phase of β-CaSiO3 which had excellent proprieties. These included an excellent degree of densification, ε r of 6.43, tan δ of 5.9 × 10 −4 and a volume resistivity of 8.20 × 10 11 Ω cm at 1 MHz, and flexural strength of 241 MPa.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Z.B. Feng,B.J. Tao,W.F. Wang,H.Y. Liu,H.T. Wu,Z.L. Zhang
Novel low temperature sintered Li 4 Mg 3 [Ti 0.8 (Mg 1/3 Ta 2/3 ) 0.2 ] 2 O 9 (LMT 0.8 (MT) 0.2 ) ceramics with 1–5 wt% LiF additives were successfully prepared by the solid-state reaction method. The effects of LiF additives on the phase composition, sintering characteristic, microstructure and microwave dielectric properties of LMT 0.8 (MT) 0.2 ceramics were investigated in detail for the first time. The sintering temperature of LMT 0.8 (MT) 0.2 ceramics could be effectively lowered to 950 °C by the addition of LiF. A single rock salt crystalline phase structure belonging to a space group of Fm-3m (No.225) was obtained through X-ray diffraction patterns. Dense uniform morphology was observed at 950 °C for LMT 0.8 (MT) 0.2 ceramics with 3–5 wt% LiF in terms of scanning electron microscopy photographs. Particularly, the LMT 0.8 (MT) 0.2 -4 wt% LiF ceramics sintered at 950 °C for 4 h possessed optimum microwave dielectric properties of ε r = 16.10, Q·f = 114,313 GHz (at 8.18 GHz) and τ f = −7.72 ppm/°C. In addition, the excellent chemical compatibility with silver metal electrodes indicated that the LMT 0.8 (MT) 0.2 -4 wt% LiF ceramics might be a promising candidate for the low-loss low temperature co-fired ceramics (LTCC) applications in microwave devices.
研究领域:
材料科学
·
陶瓷
·
微波工程
·
低温共烧陶瓷(LTCC)
✓ 已验证
DOI
高影响因子
Journal of Materiomics
·
2020
·
IF 5.797
Chi Zhang,Ying Chen,Xin Li,Haishen Ren,Genshui Wang,Xianlin Dong
Glass-free MgO-based microwave dielectric ceramics (1-x) wt% (0.98 MgO-0.02 Al 2 O 3 )-x wt% LiF (x = 0.5, 1, 2, 3, 4) were synthesized where LiF and Al 2 O 3 were utilized as sintering additive and reinforcement phase in MgO matrix respectively. It was found that ion substitution is apt to occur between LiF and MgO, leading to the formation of oxygen vacancies and MgF 2 . Nevertheless, different from ordinary liquid-phase sintering, morphologies of ceramics were distinctly altered with grains changing from polyhedron to sphere-like shape and densities underwent obvious decrease when excessive amount of LiF was introduced and we call it excessive liquid-phase sintering. Grain boundary weakening caused by this circumstance would exert an adverse effect on physical properties. Moreover, LiF addition dramatically reduced dielectric breakdown strength and altered the dielectric breakdown behavior of MgO-based ceramics, which is dominated by electrical breakdown mechanism. Combination of good properties were achieved in 1 wt% LiF modified MgO-based ceramics sintered at 950 °C which exhibited superior microwave properties (ε r = 9.56, tanδ = 9.2 × 10 −5 , Qf = 124,600 GHz), high flexural strength (184.5 MPa), high thermal conductivity (21.3 W/(m⋅K)), high coefficient of thermal expansion (∼12 ppm/°C) and moderate electrical properties (E b = 35.9 kV/mm, ρ = 4.9 × 10 12 Ω cm).
研究领域:
材料科学
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 29
·期 2
·999-1003
·
IF 2.019
Pan H. L.,Liu M. T.,Li M. F.,Ling F.,Wu H. T.
Li 6 Mg 7 Ti 3 O 16 ceramics were prepared by the conventional solid-state method with 1–5 wt% LiF as the sintering aid. Effects of LiF additions on the phase compositions, sintering characteristics, micro-structures and microwave dielectric properties of Li 6 Mg 7 Ti 3 O 16 ceramics were investigated. The LiF addition could effectively lower the sintering temperature of Li 6 Mg 7 Ti 3 O 16 ceramics from 1550 to 900 °C. For different LiF-doped compositions, the optimum dielectric permittivity ( ε
r
) and quality factor ( Q · f ) values first increased and then decreased with the increase of LiF contents, whereas the temperature coefficient of resonant frequency ( τ
f
) fluctuated between − 14.39 and − 8.21 ppm/°C. Typically, Li 6 Mg 7 Ti 3 O 16 ceramics with 4 wt% LiF sintered at 900 °C exhibited excellent microwave dielectric properties of ε
r
= 16.17, Q · f = 80,921 GHz and τ
f
= − 8.21 ppm/°C, which are promising materials for the low temperature co-fired ceramics applications.
研究领域:
材料科学
·
无机非金属材料
·
电子陶瓷
·
介电材料
·
低温共烧陶瓷技术
·
固体化学
·
功能材料
✓ 已验证
DOI
高影响因子
SOLID STATE PHENOMENA
·
2018
·
IF 0
Nan Lu,Jia Xi Liu,Gang He,Jiang Tao Li
MgO/Graphene ceramic composites were fabricated by combining combustion synthesis with spark plasma sintering. MgO/Graphene mixture powders were prepared by the combustion reaction between Mg powders and CO2 gas. Dense MgO/Graphene composites were fabricated by spark plasma sintering (SPS) using LiF as the sintering additive. The effect of the sintering temperature on microstructure and mechanical properties of the prepared MgO/Graphene ceramics was discussed. The sintering temperature of the MgO/Graphene mixture powders increased from 900°C to 1300°C. The highest density of 3.43g/cm3 and hardness of 2133MPa were obtained at 1100°C. Compared with monolithic MgO ceramics, the hardness of MgO/Graphene ceramics at the same sintering temperature was increased from 840MPa to 2133MPa.
研究领域:
材料科学
·
陶瓷工程
·
复合材料
✓ 已验证
产品关联
DOI
危险品化学品经营许可证（带存储）