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
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Jiayang Sun,Yuchen Li,Linze Lv,Longfei Wang,Weixing Xiong,Lei Huang,Qunting Qu,Yan Wang,Ming Shen,Honghe Zheng
Silicon (Si) is a promising anode material for high-energy-density lithium-ion batteries. To achieve wide practical applications, it is highly desirable to build effective solidelectrolyte interphase (SEI) with high stability and high Li + conductivity. Herein, a novel interface engineering strategy is demonstrated with the assistance of a surfactant and the self-assembly of chitosan (CS) skin on Si surface. A high coating integrity of the Si particle is obtained compared to that without surfactants. Unlike traditional surface coatings, the positive charge of the applied CS layer enables it to selectively absorb PF 6 − anions in the electrolyte. The PF 6 − aggregates in Helmholtz layer lead to the formation of anion-derived SEI enriched in LiF species. As the result, the prepared CS-decorated Si anode exhibits a high initial coulombic efficiency of 92.2% and a high rate capability of 2200 mAh g −1 capacity at 10 C rate. After 500 charge–discharge cycles, it is still able to retain a reversible capacity 1621.3 mAh g −1 . Furthermore, the excellent electrochemical property is demonstrated in full cells against NCM811 cathode. The novel interface engineering strategy provides a new SEI mechanism and demonstrates a feasible and effective way to develop high-performance Si-based lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 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
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Yuantao Yan,Xiaoli Zhao,Huanglin Dou,Jingjiang Wei,Zhihua Sun,Yu-Shi He,Qiang Dong,Haisong Xu,Xiaowei Yang
Silicon-based materials are the desirable anodes for next-generation lithium-ion batteries; however, the large volume change of Si during the charging/discharging process causes electrode fracture and an unstable solid–electrolyte interphase (SEI) layer, which severely impair their stability and Coulombic efficiency. Herein, a bundle of silicon nanoparticles is encapsulated in robust micrometer-sized MXene frameworks, in which the MXene nanosheets are precrumpled by capillary compression force to effectively buffer the stress induced by the volume change, and the abundant covalent bonds (Ti–O–Ti) between adjacent nanosheets formed through a facile thermal self-cross-linking reaction further guarantee the robustness of the MXene architecture. Both factors stabilize the electrode structure. Moreover, the abundant fluorine terminations on MXene nanosheets contribute to an in situ formation of a highly compact, durable, and mechanically robust LiF-rich SEI layer outside the frameworks upon cycling, which not only shuts down the parasitic reaction between Si and an organic electrolyte but also enhances the structural stability of MXene frameworks. Benefiting from these merits, the as-prepared anodes deliver a high specific capacity of 1797 mA h g–1 at 0.2 A g–1 and a high capacity retention of 86.7% after 500 cycles at 2 A g–1 with an average Coulombic efficiency of 99.6%. Significantly, this work paves the way for other high-capacity electrode materials with a strong volume effect.
研究领域:
材料科学
·
电化学
·
纳米能源
·
锂离子电池
·
功能材料
·
界面化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 11
·5636-5644
·
IF 11.9
Shi Zhou,Yiting Zhu,Haoran Hu,Chenghan Li,Jie Jiang,Jianyu Huang,Biao Zhang
LiF, which is considered as a key component of the solid electrolyte interface (SEI), can promote the uniform deposition of lithium. However, excessive LiF will limit the transport of lithium ions (Li+) in the SEI, resulting in low coulombic efficiency and lithium dendrite growth. Regulating the LiF concentration in the SEI is challenging but critical to the development of solid-state lithium metal batteries (SSLMBs). Herein, we synthesized porous organic polymers (POPs) that can be flexibly modified at the molecular level. These modified POPs (denoted as POPs-X-FP, X = 2, 3, 4) are added into a PEO electrolyte as fillers to form composite solid electrolytes (denoted as CSE-X-FP, X = 2, 3, 4, respectively). CSE-X-FP have different catalytic decomposition capabilities of TFSI− anions in the electrolyte due to the different fluorine atom substitution positions on the benzene ring of the POPs. Consequently, the LiF concentration in the SEI can be optimized by tuning the fluorine atom substitution positions on the benzene rings of the POPs to boost the performance of PEO based ASSLMBs. Using the LiF optimized SEI, the LiFePO4(LFP)//CSE-4-FP//Li full cell delivered a long cycle life of 1200 cycles with an initial capacity of 160.7 mA h g−1 at 0.5C. This study provides a new strategy to regulate the LiF content in the SEI layer to boost the performance of SSLMBs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Kaixin Zhao,Qi Jin,Liyuan Zhang,Lu Li,Lili Wu,Xitian Zhang
Lithium–Sulfur (Li‒S) battery is regarded as the most promising next-generation energy storage system due to their low cost and high theoretical energy density. However, the formation of dendritic morphology of Li makes the side reactions between Li metal anode and lithium polysulfides (LiPSs) more serious, leading to the depletion active materials and short lifespan of batteries , which becomes a bottle neck of their practical application. Herein, a LiF-rich Li deposition regulating layer (LDRL) is developed to protect the Li anode in Li‒S battery. The LiF-rich LDRL can effectively regulate the deposition morphology of Li, thus decreases the corrosion of the LiPSs to the Li anode. A symmetrical cell with LDRL can stably cycle for more than 700 h at a current density of 1 mA cm −2 . The Li‒S batteries using Li anodes with a LDRL presents better cycling stability (760 mAh g −1 after 100 cycles at 0.1 C) compared with the batteries using the bare Li anodes. This work provides a new idea for protecting Li anode in Li‒S battery.
研究领域:
储能系统
·
电池技术
·
材料科学
✓ 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
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 25
·1-11
·
IF 2.8
Wang Chen Bo,Gong Wei Ping,Jin Jing Ye,Bai Hao Nan,Yang Yang,Zhou Qing Wei,Yu Xue Qing,Mao Min Min,Cao Lei,Song Kai Xin,Liu Bing
SrF 2 is a promising low-permittivity fluoride with excellent microwave dielectric properties. Nevertheless, realizing densification in SrF 2 ceramics remains challenging due to their low surface energy. In this work, a series of SrF 2 – x wt%LiF ( x = 0.5–20) ceramics were synthesized using the conventional solid-state reaction method. The incorporation of LiF effectively lowered the sintering temperature from 1050 °C to 775 °C and improved the relative density from 91% to 97.1%. Outstanding microwave dielectric properties ( ɛ r = 6.39, Qf = 71,024 GHz at 20 GHz and τ f = −85.1 ppm/°C) were achieved at x = 1.0, demonstrating great potential in millimeter-wave communication applications. In addition, the present ceramics demonstrated good chemical compatibility and a well-matched coefficient of thermal expansion with silver electrodes. Finite element simulations further revealed significantly reduced thermal stress when employing the present ceramics as substrates, highlighting the strong potential for high-reliability low temperature co-fired ceramic (LTCC) applications.
研究领域:
材料科学
·
陶瓷材料
·
微波工程
·
电子封装
·
固体物理
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
LongJin Du,Jianzhong Liu,Binghong Chen,ZhiHao Sun,WeiJuan Yang
B/JP-10 suspension fuel has very high energy density and high application prospects, but energy release during its actual combustion is incomplete. In this study, the surfaces of boron nanoparticles were modified by coating the particles with LiF and AP using a two-solvent method. Thermogravimetric experiments show that the ignition temperature of boron decreases from 772°C to 599°C when the LiF coating amount is 20 wt%. In a laser ignition experiment, the AP-modified B/JP-10 suspension fuel displayed a relatively obvious "microburst" phenomenon at the end of the combustion process . The "microburst" intensifies as the amount of AP coating increases; this behavior has positive implications for the release of energy from the boron in the fuel. The oxidation of boron in 10 wt% LiF-modified fuel increased from 26.35% to 36.22% without an increase in the ambient oxygen partial pressure . AP modification increases not only the oxidation rate of boron in the fuel but also the amount of oxidizing gas produced by decomposition, and this increases the burning intensity of JP-10. LiF and AP modification can destroy the shell layer of the agglomerates formed by the combustion of suspended fuels. LiF makes it difficult to close the shell layer by reacting with B 2 O 3 to form easily sublimated substances and flaky crystals. AP breaks the shell structure due to the high pressure generated by the "microburst", thus forming a porous configuration on the surface of the agglomerate.
研究领域:
燃烧工程
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Xuelian Fu,Chaoqun Shang,Guofu Zhou,Xin Wang
Li is attractive anode for next-generation high-energy batteries. The high chemical activity, dendrite growth, and huge volume fluctuation of Li hinder its practical application. In this work, a Li–BiOF composite anode (LBOF) is obtained by combining Li metal with BiOF nanoplates through facile folding and mechanical cold rolling. Further, Li 3 Bi/LiF/Li 2 O filler is formed by the in-situ reactions of BiOF with contacted Li. In the filler, the Li 3 Bi, with high ionic conductivity and a lithiophilic nature, provides a mutually permeable channel for Li + diffusion. The low surface diffusion energy barrier of Li 3 Bi and LiF can further promote the uniform deposition of Li. The conductive lithiophilic filler can reduce the local current density and provide a spatial limitation to the deposited Li. Consequently, the symmetrical LBOF||LBOF cell can cycle stably at 1 mA cm −2 for over 1300 h. Additionally, the surface of LBOF is flat with suppressed dendrite formation and free of dead Li accumulation, and the change in electrode volume is significantly alleviated. Furthermore, the LBOF||LiFePO 4 full battery can maintain a stable cycle of more than 200 times with high capacity retention of 88.7% in a corrosive ester-based electrolyte. This simple mechanical approach is compatible with the current industrial route and is inspiring to solve the long-standing lithium-dendrite problem.
研究领域:
材料科学
·
电化学
·
电池技术
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Mo Wei,Meng Fei Zhou,Bing Liu,Cheng Chao Hu,Yu Hua Cheng,Kai Xin Song
In this work, MgF 2 – x wt%LiF ( x = 0.5, 1.0, 2.5, 4.0, 5.0) ceramics have been prepared through the standard solid-state reaction method. X-ray diffraction patterns and scanning electron micrographs revealed the successful preparation of dense MgF 2 –LiF composite ceramics at an exceptionally low sintering temperature range of 525–600°C. The optimal microwave dielectric properties ( ε r = 5.09 ± 0.03, Qf = 100,733 ± 1646 GHz, τ f = −67.4 ± 3.3 ppm/°C) were achieved in MgF 2 –0.5 wt%LiF ceramics after sintering at 550 °C for 3 h. The present ceramics exhibited an outstanding combination of low- ε r , high Qf , and an ultra-low sintering temperature, surpassing the performance of most low-temperature-fired dielectric materials. Moreover, the theoretical Qf value, extrapolated from the fitting of infrared reflectivity spectra, was calculated to be 326,583 GHz, indicating significant potential for further Qf improvement. Additionally, the chemical compatibility with Al electrodes was confirmed, suggesting promising potential for ultra-low temperature co-fired ceramic (ULTCC) applications.
研究领域:
材料科学
·
陶瓷
·
介电材料
·
微波工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Yong Wu,Honglei Liu,Deli Li,Ranlin Dong,Mengfan Bu,Bei Liu,Xiaoming Fan,Weixin Zhang
Silicon (Si) is emerging as a highly promising anode material candidate for high energy-density lithium-ion batteries (LIBs). However, its significant volume expansion during cell cycling poses a substantial challenge. Herein, fluorinated carbon derived from a fluorine-rich polymer is employed as a functional layer to engineer the solid electrolyte interface (SEI) of Si based anode material, featuring LiF-rich components in the SEI film. The strong initial Coulombic efficiency (ICE)-semi-ionic F/C linear correlation in Si@C/F nanoparticles demonstrates the essential function of semi-ionic fluorine in high-efficiency Si anodes. Semi-ionic fluorine promotes preferential LiF nucleation during SEI formation, which simultaneously suppresses lithium-consuming side reactions to enhance ICE and stabilizes the electrode interface. The homogeneous LiF distribution creates low-barrier Li + diffusion channels, markedly boosting electrode kinetics for enhanced high-rate capability. As a result, the Si@C/F composite exhibits outstanding electrochemical performance, with an ICE value as high as 88.8 %. The Si@C/F composite also demonstrates excellent long-cycling stability and high-rate capability, maintaining a reversible capacity of 971.8 mAh g −1 even under 1 A g −1 for 500 cycles. This work reveals the regulation of C F bonds in the carbon layer to construct robust SEI layer in the Si/C composites, offering a strategy for advanced Si-based anode materials with both high ICE and stable cycling performance.
研究领域:
储能
·
材料科学
·
电化学
·
纳米技术
·
电池技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）